Write docs; Update logging and error messages

Cargo.toml

@@ -1,16 +1,50 @@
-[workspace]
+[package]
-members = ["dust-lang", "dust-shell"]
+name = "dust-lang"
-default-members = ["dust-lang"]
+description = "General purpose programming language"
-resolver = "2"
+version = "0.4.1"
-
+repository = "https://git.jeffa.io/jeff/dust.git"
-[workspace.package]
-authors = ["Jeff Anderson"]
 edition = "2021"
 license = "MIT"
-readme = "README.md"
+authors = ["Jeff Anderson"]
-repository = "https://git.jeffa.io/jeff/dust.git"
+default-run = "dust"
+
+[[bin]]
+name = "dust"
+path = "src/main.rs"
 
 [profile.dev]
 opt-level = 1
 [profile.dev.package."*"]
 opt-level = 3
+
+[dependencies]
+clap = { version = "4.4.4", features = ["derive"] }
+csv = "1.2.2"
+libc = "0.2.148"
+log = "0.4.20"
+rand = "0.8.5"
+rayon = "1.8.0"
+reqwest = { version = "0.11.20", features = ["blocking", "json"] }
+serde = { version = "1.0.188", features = ["derive"] }
+serde_json = "1.0.107"
+toml = "0.8.1"
+tree-sitter = "0.20.10"
+enum-iterator = "1.4.1"
+env_logger = "0.10"
+reedline = { version = "0.28.0", features = ["clipboard", "sqlite"] }
+crossterm = "0.27.0"
+nu-ansi-term = "0.49.0"
+humantime = "2.1.0"
+stanza = "0.5.1"
+colored = "2.1.0"
+lyneate = "0.2.1"
+
+[target.'cfg(not(target_arch = "wasm32"))'.dependencies]
+env_logger = "0.10"
+
+[target.'cfg(target_arch = "wasm32")'.dependencies]
+getrandom = { version = "0.2", features = ["js"] }
+wasm-bindgen-futures = "0.4"
+
+[build-dependencies]
+cc = "1.0"

README.md

@@ -1,50 +1,59 @@
 # Dust
 
-Dust is a high-level interpreted programming language with static types that focuses on ease of use,
+High-level programming language with effortless concurrency, automatic memory management, type safety and strict error handling.
-performance and correctness.
 
-## Implementation
+![Dust version of an example from The Rust Programming Language.](https://git.jeffa.io/jeff/dust/docs/assets/example_0.png)
 
-Dust is implemented in Rust and is divided into several parts, primarily the lexer, compiler, and
+<!--toc:start-->
-virtual machine. All of Dust's components are designed with performance in mind and the codebase
+- [Dust](#dust)
-uses as few dependencies as possible.
+  - [Easy to Read and Write](#easy-to-read-and-write)
+  - [Effortless Concurrency](#effortless-concurrency)
+  - [Helpful Errors](#helpful-errors)
+  - [Debugging](#debugging)
+  - [Automatic Memory Management](#automatic-memory-management)
+  - [Installation and Usage](#installation-and-usage)
+<!--toc:end-->
 
-### Lexer
+## Easy to Read and Write
 
-The lexer emits tokens from the source code. Dust makes extensive use of Rust's zero-copy
+Dust has simple, easy-to-learn syntax.
-capabilities to avoid unnecessary allocations when creating tokens. A token, depending on its type,
-may contain a reference to some data from the source code. The data is only copied in the case of an
-error, because it improves the usability of the codebase for errors to own their data when possible.
-In a successfully executed program, no part of the source code is copied unless it is a string
-literal or identifier.
 
-### Compiler
+```js
+output('Hello world!')
+```
 
-The compiler creates a chunk, which contains all of the data needed by the virtual machine to run a
+## Effortless Concurrency
-Dust program. It does so by emitting bytecode instructions, constants and locals while parsing the
-tokens, which are generated one at a time by the lexer.
 
-#### Parsing
+Write multi-threaded code as easily as you would write code for a single thread.
 
-Dust's compiler uses a custom Pratt parser, a kind of recursive descent parser, to translate a
+```js
-sequence of tokens into a chunk.
+async {
+    output('Will this one print first?')
+    output('Or will this one?')
+    output('Who knows! Each "output" will run in its own thread!')
+}
+```
 
-#### Optimizing
+## Helpful Errors
 
-When generating instructions for a register-based virtual machine, there are opportunities to
+Dust shows you exactly where your code went wrong and suggests changes.
-optimize the generated code, usually by consolidating register use or reusing registers within an
-expression. While it is best to output optimal code in the first place, it is not always possible.
-Dust's compiler has a simple peephole optimizer that can be used to modify isolated sections of the
-instruction list through a mutable reference.
 
-### Instructions
+![Example of syntax error output.](https://git.jeffa.io/jeff/dust/docs/assets/syntax_error.png)
 
-### Virtual Machine
+## Static analysis
 
-## Previous Implementations
+Your code is always validated for safety before it is run. Other interpreted languages can fail halfway through, but Dust is able to avoid runtime errors by analyzing the program *before* it is run
 
-## Inspiration
+![Example of type error output.](https://git.jeffa.io/jeff/dust/docs/assets/type_error.png)
 
-- [The Implementation of Lua 5.0](https://www.lua.org/doc/jucs05.pdf)
+## Debugging
-- [A No-Frills Introduction to Lua 5.1 VM Instructions](https://www.mcours.net/cours/pdf/hasclic3/hasssclic818.pdf)
+
-- [Crafting Interpreters](https://craftinginterpreters.com/)
+Just set the environment variable `DUST_LOG=info` and Dust will tell you exactly what your code is doing while it's doing it. If you set `DUST_LOG=trace`, it will output detailed logs about parsing, abstraction, validation, memory management and runtime.
+
+![Example of debug output.](https://git.jeffa.io/jeff/dust/docs/assets/debugging.png)
+
+## Automatic Memory Management
+
+## Error Handling
+
+## Installation and Usage

build.rs

@@ -0,0 +1,17 @@
+fn main() {
+    let src_dir = std::path::Path::new("tree-sitter-dust/src");
+    let mut c_config = cc::Build::new();
+
+    c_config.include(src_dir);
+    c_config
+        .flag_if_supported("-Wno-unused-parameter")
+        .flag_if_supported("-Wno-unused-but-set-variable")
+        .flag_if_supported("-Wno-trigraphs");
+
+    let parser_path = src_dir.join("parser.c");
+
+    c_config.file(&parser_path);
+    c_config.compile("parser");
+
+    println!("cargo:rerun-if-changed={}", parser_path.to_str().unwrap());
+}

docs/language.md

@@ -0,0 +1,515 @@
+# Dust Language Reference
+
+!!! This is a **work in progress** and has incomplete information. !!!
+
+This is an in-depth description of the syntax and abstractions used by the Dust language. It is not
+necessary to read or understand all of it before you start using Dust. Instead, refer to it when
+you need help with the syntax or understanding how the code is run.
+
+Each section of this document corresponds to a node in the concrete syntax tree. Creating this tree
+is the first step in interpreting Dust code. Second, the syntax tree is traversed and an abstract
+tree is generated. Each node in the syntax tree corresponds to a node in the abstract tree. Third,
+the abstract tree is verified to ensure that it will not generate any values that violate the type
+restrictions. Finally, the abstract tree is run, beginning at the [root](#root).
+
+You may reference the [grammar file](tree-sitter-dust/grammar.js) and the [Tree Sitter docs]
+(https://tree-sitter.github.io/) while reading this guide to understand how the language is parsed.
+
+<!--toc:start-->
+- [Dust Language Reference](#dust-language-reference)
+  - [Root](#root)
+  - [Values](#values)
+    - [Boolean](#boolean)
+    - [Integer](#integer)
+    - [Float](#float)
+    - [Range](#range)
+    - [String](#string)
+    - [List](#list)
+    - [Map](#map)
+    - [Function](#function)
+    - [Option](#option)
+    - [Structure](#structure)
+  - [Types](#types)
+    - [Basic Types](#basic-types)
+    - [Number](#number)
+    - [Any](#any)
+    - [None](#none)
+    - [List Type](#list-type)
+    - [Map Type](#map-type)
+    - [Iter](#iter)
+    - [Function Type](#function-type)
+    - [Option Type](#option-type)
+    - [Custom Types](#custom-types)
+  - [Statements](#statements)
+    - [Assignment](#assignment)
+    - [Blocks](#blocks)
+      - [Synchronous Blocks](#synchronous-blocks)
+      - [Asynchronous Blocks](#asynchronous-blocks)
+    - [Break](#break)
+    - [For Loop](#for-loop)
+    - [While Loop](#while-loop)
+    - [If/Else](#ifelse)
+    - [Match](#match)
+    - [Pipe](#pipe)
+    - [Expression](#expression)
+  - [Expressions](#expressions)
+      - [Identifier](#identifier)
+      - [Index](#index)
+      - [Logic](#logic)
+      - [Math](#math)
+      - [Value](#value)
+      - [New](#new)
+      - [Command](#command)
+  - [Built-In Values](#built-in-values)
+  - [Comments](#comments)
+<!--toc:end-->
+
+## Root
+
+The root node represents all of the source code. It is a sequence of [statements](#statements) that
+are executed synchronously, in order. The output of the program is always the result of the final
+statement or the first error encountered.
+
+## Values
+
+There are ten kinds of value in Dust. Some are very simple and are parsed directly from the source
+code, some are collections and others are used in special ways, like functions and structures. All
+values can be assinged to an [identifier](#identifiers).
+
+Dust does not have a null type. Absent values are represented with the `none` value, which is a
+kind of [option](#option). You may not create a variable without a value and no variable can ever
+be in an 'undefined' state during execution.
+
+### Boolean
+
+Booleans are true or false. They are represented by the literal tokens `true` and `false`.
+
+### Integer
+
+Integers are whole numbers that may be positive, negative or zero. Internally, an integer is a
+signed 64-bit value.
+
+```dust
+42
+```
+
+Integers always **overflow** when their maximum or minimum value is reached. Overflowing means that
+if the value is too high or low for the 64-bit integer, it will wrap around. You can use the built-
+in values `int:max` and `int:min` to get the highest and lowest possible values.
+
+```dust
+assert_equal(int:max + 1, int:min)
+assert_equal(int:min - 1, int:max)
+```
+
+### Float
+
+A float is a numeric value with a decimal. Floats are 64-bit and, like integers, will **overflow**
+at their bounds.
+
+```dust
+42.0
+```
+
+### Range
+
+A range represents a contiguous sequence of integers. Dust ranges are **inclusive** so both the high
+and low bounds will be represented.
+
+```dust
+0..100
+```
+
+### String
+
+A string is a **utf-8** sequence used to represent text. Strings can be wrapped in single or double quotes as well as backticks.
+
+```dust
+'42'
+"42"
+`42`
+'forty-two'
+```
+
+### List
+
+A list is **collection** of values stored as a sequence and accessible by [indexing](#index) their position with an integer. Lists indexes begin at zero for the first item.
+
+```dust
+[ 42 'forty-two' ]
+[ 123, 'one', 'two', 'three' ]
+```
+
+Note that the commas are optional, including trailing commas.
+
+```dust
+[1 2 3 4 5]:2
+# Output: 3
+```
+
+### Map
+
+Maps are flexible collections with arbitrary **key-value pairs**, similar to JSON objects. A map is
+created with a pair of curly braces and its entries are variables declared inside those braces. Map
+contents can be accessed using a colon `:`. Commas may optionally be included after the key-value
+pairs.
+
+```dust
+reminder = {
+    message = "Buy milk"
+    tags = ["groceries", "home"]
+}
+
+reminder:message
+# Output: Buy milk
+```
+
+Internally a map is represented by a B-tree. The implicit advantage of using a B-tree instead of a
+hash map is that a B-tree is sorted and therefore can be easily compared to another. Maps are also
+used by the interpreter as the data structure for holding variables. You can even inspect the active
+**execution context** by calling the built-in `context()` function.
+
+The map stores each [identifier](#identifiers)'s key with a value and the value's type. For internal
+use by the interpreter, a type can be set to a key without a value. This makes it possible to check
+the types of values before they are computed.
+
+### Function
+
+A function encapsulates a section of the abstract tree so that it can be run seperately and with
+different arguments. The function body is a [block](#block), so adding `async` will cause the body
+to run like any other `async` block. Unlike some languages, there are no concepts like futures or
+async functions in Dust.
+
+Functions are **first-class values** in Dust, so they can be assigned to variables like any other
+value.
+
+```dust
+# This simple function has no arguments and no return value.
+say_hi = () <none> {
+    output("hi") # The "output" function is a built-in that prints to stdout.
+}
+
+# This function has one argument and will return a value.
+add_one = (number <num>) <num> {
+    number + 1
+}
+
+say_hi()
+assert_equal(add_one(3), 4)
+```
+
+Functions can also be **anonymous**. This is useful for using **callbacks** (i.e. functions that are
+called by another function).
+
+```dust
+# Use a callback to retain only the numeric characters in a string.
+str:retain(
+	'a1b2c3'
+	(char <str>) <bool> {
+		is_some(int:parse(char))
+	}
+)
+```
+
+### Option
+
+An option represents a value that may not be present. It has two variants: **some** and **none**. 
+
+```dust
+say_something = (message <option(str)>) <str> {
+    either_or(message, "hiya")
+}
+
+say_something(some("goodbye"))
+# goodbye
+
+say_something(none)
+# hiya
+```
+
+Dust includes built-in functions to work with option values: `is_none`, `is_some` and `either_or`.
+
+### Structure
+
+A structure is a **concrete type value**. It is a value, like any other, and can be [assigned]
+(#assignment) to an [identifier](#identifier). It can then be instantiated as a [map](#map) that
+will only allow the variables present in the structure. Default values may be provided for each
+variable in the structure, which will be propagated to the map it creates. Values without defaults
+must be given a value during instantiation.
+
+```dust
+struct User {
+    name <str>
+    email <str>
+    id <int> = generate_id()
+}
+
+bob = new User {
+    name = "Bob"
+    email = "bob@example.com"
+}
+
+# The variable "bob" is a structured map.
+```
+
+A map created by using [new](#new) is called a **structured map**. In other languages it may be
+called a "homomorphic mapped type". Dust will generate errors if you try to set any values on the
+structured map that are not allowed by the structure.
+
+## Types
+
+Dust enforces strict type checking. To make the language easier to write, **type inference** is used
+to allow variables to be declared without specifying the type. Instead, the interpreter will figure
+it out and set the strictest type possible.
+
+To make the type-setting syntax easier to distinguish from the rest of your code, a **type
+specification** is wrapped in pointed brackets. So variable assignment using types looks like this:
+
+```dust
+my_float <float> = 666.0
+```
+
+### Basic Types
+
+The simple types, and their notation are:
+
+- boolean `bool`
+- integer `int`
+- float `float`
+- string `str`
+
+### Number
+
+The `num` type may represent a value of type `int` or `float`.
+
+### Any
+
+The `any` type does not enforce type bounds.
+
+### None
+
+The `none` type indicates that no value should be found after executing the statement or block, with
+one expection: the `none` variant of the `option` type.
+
+### List Type
+
+A list's contents can be specified to create type-safe lists. The `list(str)` type would only allow
+string values. Writing `list` without the parentheses and content type is equivalent to writing
+`list(any)`.
+
+### Map Type
+
+The `map` type is unstructured and can hold any key-value pair.
+
+### Iter
+
+The `iter` type refers to types that can be used with a [for loop](#for-loop). These include `list`,
+`range`, `string` and `map`.
+
+### Function Type
+
+A function's type specification is more complex than other types. A function value must always have
+its arguments and return type specified when the **function value** is created.
+
+```dust
+my_function = (number <int>, text <str>) <none> {
+    output(number)
+    output(text)
+}
+```
+
+But what if we need to specify a **function type** without creating the function value? This is
+necessary when using callbacks or defining structures that have functions set at instantiation.
+
+```dust
+use_adder = (adder <(int) -> int>, number <int>) -> <int> {
+    adder(number)
+}
+
+use_adder(
+    (i <int>) <int> { i + 2 }
+    40
+)
+
+# Output: 42
+```
+
+```dust
+struct Message {
+    send_n_times <(str, int) -> none>
+}
+
+stdout_message = new Message {
+    send_n_times = (content <str>, n <int>) <none> {
+        for _ in 0..n {
+            output(content)
+        }
+    }
+}
+```
+
+### Option Type
+
+The `option(type)` type is expected to be either `some(value)` or `none`. The type of the value
+inside the `some` is always specified.
+
+```dust
+result <option(str)> = none
+
+for file in fs:read_dir("./") {
+    if file:size > 100 {
+        result = some(file:path)
+        break
+    }
+}
+
+output(result)
+```
+
+```dust
+get_line_break_index(text <str>) <some(int)> {
+    str:find(text, '\n')
+}
+```
+
+### Custom Types
+
+Custom types such as **structures** are referenced by their variable identifier.
+
+```dust
+File = struct {
+    path <str>
+    size <int>
+    type <str>
+}
+
+print_file_info(file <File>) <none> {
+  	info = file:path
+    		+ '\n'
+    		+ file:size
+    		+ '\n' 
+    		+ file:type
+		
+  	output(info)
+}
+```
+
+## Statements
+
+TODO
+
+### Assignment
+
+TODO
+
+### Blocks
+
+TODO
+
+#### Synchronous Blocks
+
+TODO
+
+#### Asynchronous Blocks
+
+```dust
+# An async block will run each statement in its own thread.
+async {
+    output(random_integer())
+    output(random_float())
+    output(random_boolean())
+}
+```
+
+```dust
+data = async {
+    output("Reading a file...")
+    read("examples/assets/faithful.csv")
+}
+```
+
+### Break
+
+TODO
+
+### For Loop
+
+TODO
+
+```dust
+list = [ 1, 2, 3 ]
+
+for number in list {
+    output(number + 1)
+}
+```
+
+### While Loop
+
+TODO
+
+A **while** loop continues until a predicate is false.
+
+```dust
+i = 0
+while i < 10 {
+    output(i)
+    i += 1
+}
+```
+
+### If/Else
+
+TODO
+
+### Match
+
+TODO
+
+### Pipe
+
+TODO
+
+### Expression
+
+TODO
+
+## Expressions
+
+TODO
+
+#### Identifier
+
+TODO
+
+#### Index
+
+TODO
+
+#### Logic
+
+TODO
+
+#### Math
+
+TODO
+
+#### Value
+
+TODO
+
+#### New
+
+TODO
+
+#### Command
+
+TODO
+
+## Built-In Values
+
+TODO
+
+## Comments
+
+TODO

dust-lang/Cargo.toml

@@ -1,23 +0,0 @@
-[package]
-name = "dust-lang"
-description = "Interpreter library for the Dust programming language"
-version = "0.5.0"
-authors.workspace = true
-edition.workspace = true
-license.workspace = true
-readme.workspace = true
-repository.workspace = true
-
-[dependencies]
-annotate-snippets = "0.11.4"
-colored = "2.1.0"
-log = "0.4.22"
-rand = "0.8.5"
-serde = { version = "1.0.203", features = ["derive"] }
-serde_json = "1.0.117"
-getrandom = { version = "0.2", features = [
-    "js",
-] } # Indirect dependency, for wasm builds
-
-[dev-dependencies]
-env_logger = "0.11.5"

dust-lang/src/chunk.rs

@@ -1,402 +0,0 @@
-//! In-memory representation of a Dust program or function.
-//!
-//! A chunk consists of a sequence of instructions and their positions, a list of constants, and a
-//! list of locals that can be executed by the Dust virtual machine. Chunks have a name when they
-//! belong to a named function.
-
-use std::{
-    cmp::Ordering,
-    fmt::{self, Debug, Display, Formatter},
-};
-
-use serde::{Deserialize, Serialize};
-
-use crate::{Disassembler, Instruction, Operation, Span, Type, Value};
-
-/// In-memory representation of a Dust program or function.
-///
-/// See the [module-level documentation](index.html) for more information.
-#[derive(Clone, PartialOrd, Ord, Serialize, Deserialize)]
-pub struct Chunk {
-    name: Option<String>,
-    pub is_poisoned: bool,
-
-    instructions: Vec<(Instruction, Span)>,
-    constants: Vec<Value>,
-    locals: Vec<Local>,
-
-    current_scope: Scope,
-    block_index: u8,
-}
-
-impl Chunk {
-    pub fn new(name: Option<String>) -> Self {
-        Self {
-            name,
-            is_poisoned: false,
-            instructions: Vec::new(),
-            constants: Vec::new(),
-            locals: Vec::new(),
-            current_scope: Scope::default(),
-            block_index: 0,
-        }
-    }
-
-    pub fn with_data(
-        name: Option<String>,
-        instructions: Vec<(Instruction, Span)>,
-        constants: Vec<Value>,
-        locals: Vec<Local>,
-    ) -> Self {
-        Self {
-            name,
-            is_poisoned: false,
-            instructions,
-            constants,
-            locals,
-            current_scope: Scope::default(),
-            block_index: 0,
-        }
-    }
-
-    pub fn name(&self) -> Option<&String> {
-        self.name.as_ref()
-    }
-
-    pub fn set_name(&mut self, name: String) {
-        self.name = Some(name);
-    }
-
-    pub fn len(&self) -> usize {
-        self.instructions.len()
-    }
-
-    pub fn is_empty(&self) -> bool {
-        self.instructions.is_empty()
-    }
-
-    pub fn constants(&self) -> &Vec<Value> {
-        &self.constants
-    }
-
-    pub fn constants_mut(&mut self) -> &mut Vec<Value> {
-        &mut self.constants
-    }
-
-    pub fn take_constants(self) -> Vec<Value> {
-        self.constants
-    }
-
-    pub fn instructions(&self) -> &Vec<(Instruction, Span)> {
-        &self.instructions
-    }
-
-    pub fn instructions_mut(&mut self) -> &mut Vec<(Instruction, Span)> {
-        &mut self.instructions
-    }
-
-    pub fn get_instruction(&self, index: usize) -> Result<&(Instruction, Span), ChunkError> {
-        self.instructions
-            .get(index)
-            .ok_or(ChunkError::InstructionIndexOutOfBounds { index })
-    }
-
-    pub fn locals(&self) -> &Vec<Local> {
-        &self.locals
-    }
-
-    pub fn locals_mut(&mut self) -> &mut Vec<Local> {
-        &mut self.locals
-    }
-
-    pub fn get_local(&self, index: u8) -> Result<&Local, ChunkError> {
-        self.locals
-            .get(index as usize)
-            .ok_or(ChunkError::LocalIndexOutOfBounds {
-                index: index as usize,
-            })
-    }
-
-    pub fn get_local_mut(&mut self, index: u8) -> Result<&mut Local, ChunkError> {
-        self.locals
-            .get_mut(index as usize)
-            .ok_or(ChunkError::LocalIndexOutOfBounds {
-                index: index as usize,
-            })
-    }
-
-    pub fn current_scope(&self) -> Scope {
-        self.current_scope
-    }
-
-    pub fn get_constant(&self, index: u8) -> Result<&Value, ChunkError> {
-        self.constants
-            .get(index as usize)
-            .ok_or(ChunkError::ConstantIndexOutOfBounds {
-                index: index as usize,
-            })
-    }
-
-    pub fn push_or_get_constant(&mut self, value: Value) -> u8 {
-        if let Some(index) = self
-            .constants
-            .iter()
-            .position(|constant| constant == &value)
-        {
-            return index as u8;
-        }
-
-        self.constants.push(value);
-
-        (self.constants.len() - 1) as u8
-    }
-
-    pub fn get_identifier(&self, local_index: u8) -> Option<String> {
-        self.locals.get(local_index as usize).and_then(|local| {
-            self.constants
-                .get(local.identifier_index as usize)
-                .map(|value| value.to_string())
-        })
-    }
-
-    pub fn begin_scope(&mut self) {
-        self.block_index += 1;
-        self.current_scope.block_index = self.block_index;
-        self.current_scope.depth += 1;
-    }
-
-    pub fn end_scope(&mut self) {
-        self.current_scope.depth -= 1;
-
-        if self.current_scope.depth == 0 {
-            self.current_scope.block_index = 0;
-        } else {
-            self.current_scope.block_index -= 1;
-        }
-    }
-
-    pub fn expect_not_poisoned(&self) -> Result<(), ChunkError> {
-        if self.is_poisoned {
-            Err(ChunkError::PoisonedChunk)
-        } else {
-            Ok(())
-        }
-    }
-
-    pub fn get_constant_type(&self, constant_index: u8) -> Option<Type> {
-        self.constants
-            .get(constant_index as usize)
-            .map(|value| value.r#type())
-    }
-
-    pub fn get_local_type(&self, local_index: u8) -> Option<Type> {
-        self.locals.get(local_index as usize)?.r#type.clone()
-    }
-
-    pub fn get_register_type(&self, register_index: u8) -> Option<Type> {
-        let local_type_option = self
-            .locals
-            .iter()
-            .find(|local| local.register_index == register_index)
-            .map(|local| local.r#type.clone());
-
-        if let Some(local_type) = local_type_option {
-            return local_type;
-        }
-
-        self.instructions
-            .iter()
-            .enumerate()
-            .find_map(|(index, (instruction, _))| {
-                if let Operation::LoadList = instruction.operation() {
-                    if instruction.a() == register_index {
-                        let mut length = (instruction.c() - instruction.b() + 1) as usize;
-                        let mut item_type = Type::Any;
-                        let distance_to_end = self.len() - index;
-
-                        for (instruction, _) in self
-                            .instructions()
-                            .iter()
-                            .rev()
-                            .skip(distance_to_end)
-                            .take(length)
-                        {
-                            if let Operation::Close = instruction.operation() {
-                                length -= (instruction.c() - instruction.b()) as usize;
-                            } else if let Type::Any = item_type {
-                                item_type = instruction.yielded_type(self).unwrap_or(Type::Any);
-                            }
-                        }
-
-                        return Some(Type::List {
-                            item_type: Box::new(item_type),
-                            length,
-                        });
-                    }
-                }
-
-                if instruction.yields_value() && instruction.a() == register_index {
-                    instruction.yielded_type(self)
-                } else {
-                    None
-                }
-            })
-    }
-
-    pub fn return_type(&self) -> Option<Type> {
-        let returns_value = self
-            .instructions()
-            .last()
-            .map(|(instruction, _)| {
-                debug_assert!(matches!(instruction.operation(), Operation::Return));
-
-                instruction.b_as_boolean()
-            })
-            .unwrap_or(false);
-
-        if returns_value {
-            self.instructions.iter().rev().find_map(|(instruction, _)| {
-                if instruction.yields_value() {
-                    instruction.yielded_type(self)
-                } else {
-                    None
-                }
-            })
-        } else {
-            None
-        }
-    }
-
-    pub fn disassembler(&self) -> Disassembler {
-        Disassembler::new(self)
-    }
-}
-
-impl Display for Chunk {
-    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
-        let disassembler = self.disassembler().styled(false);
-
-        write!(f, "{}", disassembler.disassemble())
-    }
-}
-
-impl Debug for Chunk {
-    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
-        let disassembly = self.disassembler().styled(false).disassemble();
-
-        if cfg!(debug_assertions) {
-            write!(f, "\n{}", disassembly)
-        } else {
-            write!(f, "{}", disassembly)
-        }
-    }
-}
-
-impl Eq for Chunk {}
-
-impl PartialEq for Chunk {
-    fn eq(&self, other: &Self) -> bool {
-        self.instructions == other.instructions
-            && self.constants == other.constants
-            && self.locals == other.locals
-    }
-}
-
-/// A scoped variable.
-#[derive(Debug, Clone, Eq, PartialEq, PartialOrd, Ord, Serialize, Deserialize)]
-pub struct Local {
-    /// The index of the identifier in the constants table.
-    pub identifier_index: u8,
-
-    /// The expected type of the local's value.
-    pub r#type: Option<Type>,
-
-    /// Whether the local is mutable.
-    pub is_mutable: bool,
-
-    /// Scope where the variable was declared.
-    pub scope: Scope,
-
-    /// Expected location of a local's value.
-    pub register_index: u8,
-}
-
-impl Local {
-    /// Creates a new Local instance.
-    pub fn new(
-        identifier_index: u8,
-        r#type: Option<Type>,
-        mutable: bool,
-        scope: Scope,
-        register_index: u8,
-    ) -> Self {
-        Self {
-            identifier_index,
-            r#type,
-            is_mutable: mutable,
-            scope,
-            register_index,
-        }
-    }
-}
-
-/// Variable locality, as defined by its depth and block index.
-///
-/// The `block index` is a unique identifier for a block within a chunk. It is used to differentiate
-/// between blocks that are not nested together but have the same depth, i.e. sibling scopes. If the
-/// `block_index` is 0, then the scope is the root scope of the chunk. The `block_index` is always 0
-/// when the `depth` is 0. See [Chunk::begin_scope][] and [Chunk::end_scope][] to see how scopes are
-/// incremented and decremented.
-#[derive(Debug, Clone, Copy, Default, Eq, PartialEq, PartialOrd, Ord, Serialize, Deserialize)]
-pub struct Scope {
-    /// Level of block nesting.
-    pub depth: u8,
-    /// Index of the block in the chunk.
-    pub block_index: u8,
-}
-
-impl Scope {
-    pub fn new(depth: u8, block_index: u8) -> Self {
-        Self { depth, block_index }
-    }
-
-    pub fn contains(&self, other: &Self) -> bool {
-        match self.depth.cmp(&other.depth) {
-            Ordering::Less => false,
-            Ordering::Greater => self.block_index >= other.block_index,
-            Ordering::Equal => self.block_index == other.block_index,
-        }
-    }
-}
-
-impl Display for Scope {
-    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
-        write!(f, "({}, {})", self.depth, self.block_index)
-    }
-}
-
-/// Errors that can occur when using a [`Chunk`].
-#[derive(Clone, Debug, PartialEq)]
-pub enum ChunkError {
-    ConstantIndexOutOfBounds { index: usize },
-    InstructionIndexOutOfBounds { index: usize },
-    LocalIndexOutOfBounds { index: usize },
-    PoisonedChunk,
-}
-
-impl Display for ChunkError {
-    fn fmt(&self, f: &mut Formatter) -> fmt::Result {
-        match self {
-            ChunkError::ConstantIndexOutOfBounds { index } => {
-                write!(f, "Constant index {} out of bounds", index)
-            }
-            ChunkError::InstructionIndexOutOfBounds { index } => {
-                write!(f, "Instruction index {} out of bounds", index)
-            }
-            ChunkError::LocalIndexOutOfBounds { index } => {
-                write!(f, "Local index {} out of bounds", index)
-            }
-            ChunkError::PoisonedChunk => write!(f, "Chunk is poisoned"),
-        }
-    }
-}

dust-lang/src/disassembler.rs

@@ -1,366 +0,0 @@
-//! Tool for disassembling chunks into a human-readable format.
-//!
-//! A disassembler can be created by calling [Chunk::disassembler][] or by instantiating one with
-//! [Disassembler::new][].
-//!
-//! # Options
-//!
-//! The disassembler can be customized with the 'styled' option, which will apply ANSI color codes
-//! to the output.
-//!
-//! # Output
-//!
-//! The output of [Disassembler::disassemble] is a string that can be printed to the console or
-//! written to a file. Below is an example of the disassembly for a simple "Hello, world!" program.
-//!
-//! ```text
-//! ┌──────────────────────────────────────────────────────────────────────────────┐
-//! │                             <file name omitted>                              │
-//! │                                                                              │
-//! │                         write_line("Hello, world!")                          │
-//! │                                                                              │
-//! │             3 instructions, 1 constants, 0 locals, returns none              │
-//! │                                                                              │
-//! │                                 Instructions                                 │
-//! │                                 ------------                                 │
-//! │ i  BYTECODE OPERATION             INFO               TYPE         POSITION   │
-//! │--- -------- ------------- -------------------- ---------------- ------------ │
-//! │ 0        03 LOAD_CONSTANT R0 = C0                    str        (11, 26)     │
-//! │ 1   1390117 CALL_NATIVE   write_line(R0)                        (0, 27)      │
-//! │ 2        18 RETURN                                              (27, 27)     │
-//! │┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈│
-//! │                                    Locals                                    │
-//! │                                    ------                                    │
-//! │            i  IDENTIFIER       TYPE       MUTABLE  SCOPE  REGISTER           │
-//! │           --- ---------- ---------------- ------- ------- --------           │
-//! │┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈┈│
-//! │                                  Constants                                   │
-//! │                                  ---------                                   │
-//! │                              i       VALUE                                   │
-//! │                             --- ---------------                              │
-//! │                              0   Hello, world!                               │
-//! └──────────────────────────────────────────────────────────────────────────────┘
-//! ```
-use std::env::current_exe;
-
-use colored::Colorize;
-
-use crate::{Chunk, ConcreteValue, Local, Value};
-
-const INSTRUCTION_HEADER: [&str; 4] = [
-    "Instructions",
-    "------------",
-    " i  BYTECODE OPERATION             INFO               TYPE        POSITION ",
-    "--- -------- ------------- -------------------- ---------------- ----------",
-];
-
-const CONSTANT_HEADER: [&str; 4] = [
-    "Constants",
-    "---------",
-    " i       VALUE     ",
-    "--- ---------------",
-];
-
-const LOCAL_HEADER: [&str; 4] = [
-    "Locals",
-    "------",
-    " i  IDENTIFIER       TYPE       MUTABLE  SCOPE  REGISTER",
-    "--- ---------- ---------------- ------- ------- --------",
-];
-
-/// Builder that constructs a human-readable representation of a chunk.
-///
-/// See the [module-level documentation](index.html) for more information.
-pub struct Disassembler<'a> {
-    output: String,
-    chunk: &'a Chunk,
-    source: Option<&'a str>,
-
-    // Options
-    styled: bool,
-    indent: usize,
-}
-
-impl<'a> Disassembler<'a> {
-    pub fn new(chunk: &'a Chunk) -> Self {
-        Self {
-            output: String::new(),
-            chunk,
-            source: None,
-            styled: false,
-            indent: 0,
-        }
-    }
-
-    /// The default width of the disassembly output. To correctly align the output, this should
-    /// return the width of the longest line that the disassembler is guaranteed to produce.
-    pub fn default_width() -> usize {
-        let longest_line = INSTRUCTION_HEADER[3];
-
-        longest_line.chars().count().max(80)
-    }
-
-    pub fn source(mut self, source: &'a str) -> Self {
-        self.source = Some(source);
-
-        self
-    }
-
-    pub fn styled(mut self, styled: bool) -> Self {
-        self.styled = styled;
-
-        self
-    }
-
-    pub fn indent(mut self, indent: usize) -> Self {
-        self.indent = indent;
-
-        self
-    }
-
-    fn push(
-        &mut self,
-        text: &str,
-        center: bool,
-        style_bold: bool,
-        style_dim: bool,
-        add_border: bool,
-    ) {
-        let width = Disassembler::default_width();
-        let characters = text.chars().collect::<Vec<char>>();
-        let content_width = if add_border { width - 2 } else { width };
-        let (line_characters, remainder) = characters
-            .split_at_checked(content_width)
-            .unwrap_or((characters.as_slice(), &[]));
-        let (left_pad_length, right_pad_length) = {
-            let extra_space = content_width.saturating_sub(characters.len());
-
-            if center {
-                (extra_space / 2, extra_space / 2 + extra_space % 2)
-            } else {
-                (0, extra_space)
-            }
-        };
-        let content = if style_bold {
-            line_characters
-                .iter()
-                .collect::<String>()
-                .bold()
-                .to_string()
-        } else if style_dim {
-            line_characters
-                .iter()
-                .collect::<String>()
-                .dimmed()
-                .to_string()
-        } else {
-            line_characters.iter().collect::<String>()
-        };
-        let length_before_content = self.output.chars().count();
-
-        for _ in 0..self.indent {
-            self.output.push_str("│   ");
-        }
-
-        if add_border {
-            self.output.push('│');
-        }
-
-        self.output.push_str(&" ".repeat(left_pad_length));
-        self.output.push_str(&content);
-        self.output.push_str(&" ".repeat(right_pad_length));
-
-        let length_after_content = self.output.chars().count();
-        let line_length = length_after_content - length_before_content;
-
-        if line_length < content_width - 1 {
-            self.output
-                .push_str(&" ".repeat(content_width - line_length));
-        }
-
-        if add_border {
-            self.output.push('│');
-        }
-
-        self.output.push('\n');
-
-        if !remainder.is_empty() {
-            self.push(
-                remainder.iter().collect::<String>().as_str(),
-                center,
-                style_bold,
-                style_dim,
-                add_border,
-            );
-        }
-    }
-
-    fn push_header(&mut self, header: &str) {
-        self.push(header, true, self.styled, false, true);
-    }
-
-    fn push_details(&mut self, details: &str) {
-        self.push(details, true, false, false, true);
-    }
-
-    fn push_border(&mut self, border: &str) {
-        self.push(border, false, false, false, false);
-    }
-
-    fn push_empty(&mut self) {
-        self.push("", false, false, false, true);
-    }
-
-    pub fn disassemble(mut self) -> String {
-        let width = Disassembler::default_width();
-        let top_border = "┌".to_string() + &"─".repeat(width - 2) + "┐";
-        let section_border = "│".to_string() + &"┈".repeat(width - 2) + "│";
-        let bottom_border = "└".to_string() + &"─".repeat(width - 2) + "┘";
-        let name_display = self
-            .chunk
-            .name()
-            .map(|identifier| identifier.to_string())
-            .unwrap_or_else(|| {
-                current_exe()
-                    .map(|path| path.to_string_lossy().to_string())
-                    .unwrap_or("Chunk Disassembly".to_string())
-            });
-
-        self.push_border(&top_border);
-        self.push_header(&name_display);
-
-        if let Some(source) = self.source {
-            self.push_empty();
-            self.push_details(
-                &source
-                    .replace("  ", "")
-                    .replace("\n\n", " ")
-                    .replace('\n', " "),
-            );
-            self.push_empty();
-        }
-
-        let info_line = format!(
-            "{} instructions, {} constants, {} locals, returns {}",
-            self.chunk.len(),
-            self.chunk.constants().len(),
-            self.chunk.locals().len(),
-            self.chunk
-                .return_type()
-                .map(|r#type| r#type.to_string())
-                .unwrap_or("none".to_string())
-        );
-
-        self.push(&info_line, true, false, true, true);
-        self.push_empty();
-
-        for line in INSTRUCTION_HEADER {
-            self.push_header(line);
-        }
-
-        for (index, (instruction, position)) in self.chunk.instructions().iter().enumerate() {
-            let bytecode = format!("{:02X}", u32::from(instruction));
-            let operation = instruction.operation().to_string();
-            let info = instruction.disassembly_info(self.chunk);
-            let type_display = instruction
-                .yielded_type(self.chunk)
-                .map(|r#type| {
-                    let type_string = r#type.to_string();
-
-                    if type_string.len() > 16 {
-                        format!("{type_string:.13}...")
-                    } else {
-                        type_string
-                    }
-                })
-                .unwrap_or(String::with_capacity(0));
-            let position = position.to_string();
-
-            let instruction_display = format!(
-                "{index:^3} {bytecode:>8} {operation:13} {info:^20} {type_display:^16} {position:10}"
-            );
-
-            self.push_details(&instruction_display);
-        }
-
-        self.push_border(&section_border);
-
-        for line in LOCAL_HEADER {
-            self.push_header(line);
-        }
-
-        for (
-            index,
-            Local {
-                identifier_index,
-                r#type,
-                scope,
-                register_index,
-                is_mutable: mutable,
-            },
-        ) in self.chunk.locals().iter().enumerate()
-        {
-            let identifier_display = self
-                .chunk
-                .constants()
-                .get(*identifier_index as usize)
-                .map(|value| value.to_string())
-                .unwrap_or_else(|| "unknown".to_string());
-            let type_display = r#type
-                .as_ref()
-                .map(|r#type| {
-                    let type_string = r#type.to_string();
-
-                    if type_string.len() > 16 {
-                        format!("{type_string:.13}...")
-                    } else {
-                        type_string
-                    }
-                })
-                .unwrap_or("unknown".to_string());
-            let local_display = format!(
-                "{index:^3} {identifier_display:10} {type_display:16} {mutable:7} {scope:7} {register_index:8}"
-            );
-
-            self.push_details(&local_display);
-        }
-
-        self.push_border(&section_border);
-
-        for line in CONSTANT_HEADER {
-            self.push_header(line);
-        }
-
-        for (index, value) in self.chunk.constants().iter().enumerate() {
-            let value_display = {
-                let value_string = value.to_string();
-
-                if value_string.len() > 15 {
-                    format!("{value_string:.12}...")
-                } else {
-                    value_string
-                }
-            };
-            let constant_display = format!("{index:^3} {value_display:^15}");
-
-            self.push_details(&constant_display);
-
-            if let Value::Concrete(ConcreteValue::Function(function)) = value {
-                let function_disassembly = function
-                    .chunk()
-                    .disassembler()
-                    .styled(self.styled)
-                    .indent(self.indent + 1)
-                    .disassemble();
-
-                self.output.push_str(&function_disassembly);
-            }
-        }
-
-        self.push_border(&bottom_border);
-
-        let _ = self.output.trim_end_matches('\n');
-
-        self.output
-    }
-}

dust-lang/src/dust_error.rs

@@ -1,66 +0,0 @@
-//! Top-level Dust errors with source code annotations.
-use annotate_snippets::{Level, Renderer, Snippet};
-
-use crate::{vm::VmError, CompileError, Span};
-
-/// A top-level error that can occur during the execution of Dust code.
-///
-/// This error can display nicely formatted messages with source code annotations.
-#[derive(Debug, PartialEq)]
-pub enum DustError<'src> {
-    Compile {
-        error: CompileError,
-        source: &'src str,
-    },
-    Runtime {
-        error: VmError,
-        source: &'src str,
-    },
-}
-
-impl<'src> DustError<'src> {
-    pub fn report(&self) -> String {
-        let mut report = String::new();
-        let renderer = Renderer::styled();
-
-        match self {
-            DustError::Runtime { error, source } => {
-                let position = error.position();
-                let label = format!("{}: {}", VmError::title(), error.description());
-                let details = error
-                    .details()
-                    .unwrap_or_else(|| "While running this code".to_string());
-                let message = Level::Error.title(&label).snippet(
-                    Snippet::source(source)
-                        .fold(false)
-                        .annotation(Level::Error.span(position.0..position.1).label(&details)),
-                );
-
-                report.push_str(&renderer.render(message).to_string());
-            }
-            DustError::Compile { error, source } => {
-                let position = error.position();
-                let label = format!("{}: {}", CompileError::title(), error.description());
-                let details = error
-                    .details()
-                    .unwrap_or_else(|| "While parsing this code".to_string());
-                let message = Level::Error.title(&label).snippet(
-                    Snippet::source(source)
-                        .fold(false)
-                        .annotation(Level::Error.span(position.0..position.1).label(&details)),
-                );
-
-                report.push_str(&renderer.render(message).to_string());
-            }
-        }
-
-        report
-    }
-}
-
-pub trait AnnotatedError {
-    fn title() -> &'static str;
-    fn description(&self) -> &'static str;
-    fn details(&self) -> Option<String>;
-    fn position(&self) -> Span;
-}

dust-lang/src/formatter.rs

@@ -1,224 +0,0 @@
-//! Formatting tools
-use std::mem::replace;
-
-use colored::{ColoredString, Colorize, CustomColor};
-
-use crate::{CompileError, DustError, LexError, Lexer, Token};
-
-pub fn format(source: &str, line_numbers: bool, colored: bool) -> Result<String, DustError> {
-    let lexer = Lexer::new(source);
-    let formatted = Formatter::new(lexer)
-        .line_numbers(line_numbers)
-        .colored(colored)
-        .format()
-        .map_err(|error| DustError::Compile {
-            error: CompileError::Lex(error),
-            source,
-        })?;
-
-    Ok(formatted)
-}
-
-#[derive(Debug)]
-pub struct Formatter<'src> {
-    lexer: Lexer<'src>,
-    output_lines: Vec<(String, LineKind, usize)>,
-    next_line: String,
-    indent: usize,
-
-    current_token: Token<'src>,
-    previous_token: Token<'src>,
-
-    // Options
-    line_numbers: bool,
-    colored: bool,
-}
-
-impl<'src> Formatter<'src> {
-    pub fn new(mut lexer: Lexer<'src>) -> Self {
-        let (current_token, _) = lexer.next_token().unwrap();
-
-        Self {
-            lexer,
-            output_lines: Vec::new(),
-            next_line: String::new(),
-            indent: 0,
-            current_token,
-            previous_token: Token::Eof,
-            line_numbers: false,
-            colored: false,
-        }
-    }
-
-    pub fn line_numbers(mut self, line_numbers: bool) -> Self {
-        self.line_numbers = line_numbers;
-
-        self
-    }
-
-    pub fn colored(mut self, colored: bool) -> Self {
-        self.colored = colored;
-
-        self
-    }
-
-    pub fn format(&mut self) -> Result<String, LexError> {
-        let mut line_kind = LineKind::Empty;
-
-        self.advance()?;
-
-        while self.current_token != Token::Eof {
-            use Token::*;
-
-            if self.current_token.is_expression() && line_kind != LineKind::Assignment {
-                line_kind = LineKind::Expression;
-            }
-
-            match self.current_token {
-                Boolean(boolean) => {
-                    self.push_colored(boolean.red());
-                }
-                Byte(byte) => {
-                    self.push_colored(byte.green());
-                }
-                Character(character) => {
-                    self.push_colored(
-                        character
-                            .to_string()
-                            .custom_color(CustomColor::new(225, 150, 150)),
-                    );
-                }
-                Float(float) => {
-                    self.push_colored(float.yellow());
-                }
-                Identifier(identifier) => {
-                    self.push_colored(identifier.blue());
-                    self.next_line.push(' ');
-                }
-                Integer(integer) => {
-                    self.push_colored(integer.cyan());
-                }
-                String(string) => {
-                    self.push_colored(string.magenta());
-                }
-                LeftCurlyBrace => {
-                    self.next_line.push_str(self.current_token.as_str());
-                    self.commit_line(LineKind::OpenBlock);
-
-                    self.indent += 1;
-                }
-                RightCurlyBrace => {
-                    self.commit_line(LineKind::CloseBlock);
-                    self.next_line.push_str(self.current_token.as_str());
-
-                    self.indent -= 1;
-                }
-                Semicolon => {
-                    if line_kind != LineKind::Assignment {
-                        line_kind = LineKind::Statement;
-                    }
-
-                    self.next_line.push_str(self.current_token.as_str());
-                    self.commit_line(line_kind);
-                }
-                Let => {
-                    line_kind = LineKind::Assignment;
-
-                    self.push_colored(self.current_token.as_str().bold());
-                    self.next_line.push(' ');
-                }
-                Break | Loop | Return | While => {
-                    line_kind = LineKind::Statement;
-
-                    self.push_colored(self.current_token.as_str().bold());
-                    self.next_line.push(' ');
-                }
-                token => {
-                    self.next_line.push_str(token.as_str());
-                    self.next_line.push(' ');
-                }
-            }
-        }
-
-        let mut previous_index = 0;
-        let mut current_index = 1;
-
-        while current_index < self.output_lines.len() {
-            let (_, previous, _) = &self.output_lines[previous_index];
-            let (_, current, _) = &self.output_lines[current_index];
-
-            match (previous, current) {
-                (LineKind::Empty, _)
-                | (_, LineKind::Empty)
-                | (LineKind::OpenBlock, _)
-                | (_, LineKind::CloseBlock) => {}
-                (left, right) if left == right => {}
-                _ => {
-                    self.output_lines
-                        .insert(current_index, ("".to_string(), LineKind::Empty, 0));
-                }
-            }
-
-            previous_index += 1;
-            current_index += 1;
-        }
-
-        let formatted = String::with_capacity(
-            self.output_lines
-                .iter()
-                .fold(0, |total, (line, _, _)| total + line.len()),
-        );
-
-        Ok(self.output_lines.iter().enumerate().fold(
-            formatted,
-            |acc, (index, (line, _, indent))| {
-                let index = if index == 0 {
-                    format!("{:<3}| ", index + 1).dimmed()
-                } else {
-                    format!("\n{:<3}| ", index + 1).dimmed()
-                };
-                let left_pad = "    ".repeat(*indent);
-
-                format!("{}{}{}{}", acc, index, left_pad, line)
-            },
-        ))
-    }
-
-    fn advance(&mut self) -> Result<(), LexError> {
-        if self.lexer.is_eof() {
-            return Ok(());
-        }
-
-        let (new_token, position) = self.lexer.next_token()?;
-
-        log::info!(
-            "Parsing {} at {}",
-            new_token.to_string().bold(),
-            position.to_string()
-        );
-
-        self.previous_token = replace(&mut self.current_token, new_token);
-
-        Ok(())
-    }
-
-    fn push_colored(&mut self, colored: ColoredString) {
-        self.next_line.push_str(&format!("{}", colored));
-    }
-
-    fn commit_line(&mut self, line_kind: LineKind) {
-        self.output_lines
-            .push((self.next_line.clone(), line_kind, self.indent));
-        self.next_line.clear();
-    }
-}
-
-#[derive(Debug, Clone, Copy, PartialEq)]
-pub enum LineKind {
-    Empty,
-    Assignment,
-    Expression,
-    Statement,
-    OpenBlock,
-    CloseBlock,
-}

dust-lang/src/instruction.rs

@@ -1,902 +0,0 @@
-//! An operation and its arguments for the Dust virtual machine.
-//!
-//! Each instruction is a 32-bit unsigned integer that is divided into five fields:
-//! - Bits 0-6: The operation code.
-//! - Bit 7: A flag indicating whether the B argument is a constant.
-//! - Bit 8: A flag indicating whether the C argument is a constant.
-//! - Bits 9-16: The A argument,
-//! - Bits 17-24: The B argument.
-//! - Bits 25-32: The C argument.
-//!
-//! Be careful when working with instructions directly. When modifying an instruction, be sure to
-//! account for the fact that setting the A, B, or C arguments to 0 will have no effect. It is
-//! usually best to remove instructions and insert new ones in their place instead of mutating them.
-
-use serde::{Deserialize, Serialize};
-
-use crate::{Chunk, NativeFunction, Operation, Type};
-
-/// An operation and its arguments for the Dust virtual machine.
-///
-/// See the [module-level documentation](index.html) for more information.
-#[derive(Debug, Clone, Copy, Eq, PartialEq, PartialOrd, Ord, Hash, Serialize, Deserialize)]
-pub struct Instruction(u32);
-
-impl Instruction {
-    pub fn with_operation(operation: Operation) -> Instruction {
-        Instruction(operation as u32)
-    }
-
-    pub fn r#move(to_register: u8, from_register: u8) -> Instruction {
-        let mut instruction = Instruction(Operation::Move as u32);
-
-        instruction.set_a(to_register);
-        instruction.set_b(from_register);
-
-        instruction
-    }
-
-    pub fn close(from_register: u8, to_register: u8) -> Instruction {
-        let mut instruction = Instruction(Operation::Close as u32);
-
-        instruction.set_b(from_register);
-        instruction.set_c(to_register);
-
-        instruction
-    }
-
-    pub fn load_boolean(to_register: u8, value: bool, skip: bool) -> Instruction {
-        let mut instruction = Instruction(Operation::LoadBoolean as u32);
-
-        instruction.set_a(to_register);
-        instruction.set_b_to_boolean(value);
-        instruction.set_c_to_boolean(skip);
-
-        instruction
-    }
-
-    pub fn load_constant(to_register: u8, constant_index: u8, skip: bool) -> Instruction {
-        let mut instruction = Instruction(Operation::LoadConstant as u32);
-
-        instruction.set_a(to_register);
-        instruction.set_b(constant_index);
-        instruction.set_c_to_boolean(skip);
-
-        instruction
-    }
-
-    pub fn load_list(to_register: u8, start_register: u8) -> Instruction {
-        let mut instruction = Instruction(Operation::LoadList as u32);
-
-        instruction.set_a(to_register);
-        instruction.set_b(start_register);
-
-        instruction
-    }
-
-    pub fn load_self(to_register: u8) -> Instruction {
-        let mut instruction = Instruction(Operation::LoadSelf as u32);
-
-        instruction.set_a(to_register);
-
-        instruction
-    }
-
-    pub fn define_local(to_register: u8, local_index: u8, is_mutable: bool) -> Instruction {
-        let mut instruction = Instruction(Operation::DefineLocal as u32);
-
-        instruction.set_a(to_register);
-        instruction.set_b(local_index);
-        instruction.set_c(if is_mutable { 1 } else { 0 });
-
-        instruction
-    }
-
-    pub fn get_local(to_register: u8, local_index: u8) -> Instruction {
-        let mut instruction = Instruction(Operation::GetLocal as u32);
-
-        instruction.set_a(to_register);
-        instruction.set_b(local_index);
-
-        instruction
-    }
-
-    pub fn set_local(from_register: u8, local_index: u8) -> Instruction {
-        let mut instruction = Instruction(Operation::SetLocal as u32);
-
-        instruction.set_a(from_register);
-        instruction.set_b(local_index);
-
-        instruction
-    }
-
-    pub fn add(to_register: u8, left_index: u8, right_index: u8) -> Instruction {
-        let mut instruction = Instruction(Operation::Add as u32);
-
-        instruction.set_a(to_register);
-        instruction.set_b(left_index);
-        instruction.set_c(right_index);
-
-        instruction
-    }
-
-    pub fn subtract(to_register: u8, left_index: u8, right_index: u8) -> Instruction {
-        let mut instruction = Instruction(Operation::Subtract as u32);
-
-        instruction.set_a(to_register);
-        instruction.set_b(left_index);
-        instruction.set_c(right_index);
-
-        instruction
-    }
-
-    pub fn multiply(to_register: u8, left_index: u8, right_index: u8) -> Instruction {
-        let mut instruction = Instruction(Operation::Multiply as u32);
-
-        instruction.set_a(to_register);
-        instruction.set_b(left_index);
-        instruction.set_c(right_index);
-
-        instruction
-    }
-
-    pub fn divide(to_register: u8, left_index: u8, right_index: u8) -> Instruction {
-        let mut instruction = Instruction(Operation::Divide as u32);
-
-        instruction.set_a(to_register);
-        instruction.set_b(left_index);
-        instruction.set_c(right_index);
-
-        instruction
-    }
-
-    pub fn modulo(to_register: u8, left_index: u8, right_index: u8) -> Instruction {
-        let mut instruction = Instruction(Operation::Modulo as u32);
-
-        instruction.set_a(to_register);
-        instruction.set_b(left_index);
-        instruction.set_c(right_index);
-
-        instruction
-    }
-
-    pub fn test(to_register: u8, test_value: bool) -> Instruction {
-        let mut instruction = Instruction(Operation::Test as u32);
-
-        instruction.set_a(to_register);
-        instruction.set_c_to_boolean(test_value);
-
-        instruction
-    }
-
-    pub fn test_set(to_register: u8, argument_index: u8, test_value: bool) -> Instruction {
-        let mut instruction = Instruction(Operation::TestSet as u32);
-
-        instruction.set_a(to_register);
-        instruction.set_b(argument_index);
-        instruction.set_c_to_boolean(test_value);
-
-        instruction
-    }
-
-    pub fn equal(comparison_boolean: bool, left_index: u8, right_index: u8) -> Instruction {
-        let mut instruction = Instruction(Operation::Equal as u32);
-
-        instruction.set_a_to_boolean(comparison_boolean);
-        instruction.set_b(left_index);
-        instruction.set_c(right_index);
-
-        instruction
-    }
-
-    pub fn less(comparison_boolean: bool, left_index: u8, right_index: u8) -> Instruction {
-        let mut instruction = Instruction(Operation::Less as u32);
-
-        instruction.set_a_to_boolean(comparison_boolean);
-        instruction.set_b(left_index);
-        instruction.set_c(right_index);
-
-        instruction
-    }
-
-    pub fn less_equal(comparison_boolean: bool, left_index: u8, right_index: u8) -> Instruction {
-        let mut instruction = Instruction(Operation::LessEqual as u32);
-
-        instruction.set_a_to_boolean(comparison_boolean);
-        instruction.set_b(left_index);
-        instruction.set_c(right_index);
-
-        instruction
-    }
-
-    pub fn negate(to_register: u8, from_index: u8) -> Instruction {
-        let mut instruction = Instruction(Operation::Negate as u32);
-
-        instruction.set_a(to_register);
-        instruction.set_b(from_index);
-
-        instruction
-    }
-
-    pub fn not(to_register: u8, from_index: u8) -> Instruction {
-        let mut instruction = Instruction(Operation::Not as u32);
-
-        instruction.set_a(to_register);
-        instruction.set_b(from_index);
-
-        instruction
-    }
-
-    pub fn jump(jump_offset: u8, is_positive: bool) -> Instruction {
-        let mut instruction = Instruction(Operation::Jump as u32);
-
-        instruction.set_b(jump_offset);
-        instruction.set_c_to_boolean(is_positive);
-
-        instruction
-    }
-
-    pub fn call(to_register: u8, function_register: u8, argument_count: u8) -> Instruction {
-        let mut instruction = Instruction(Operation::Call as u32);
-
-        instruction.set_a(to_register);
-        instruction.set_b(function_register);
-        instruction.set_c(argument_count);
-
-        instruction
-    }
-
-    pub fn call_native(
-        to_register: u8,
-        native_fn: NativeFunction,
-        argument_count: u8,
-    ) -> Instruction {
-        let mut instruction = Instruction(Operation::CallNative as u32);
-        let native_fn_byte = native_fn as u8;
-
-        instruction.set_a(to_register);
-        instruction.set_b(native_fn_byte);
-        instruction.set_c(argument_count);
-
-        instruction
-    }
-
-    pub fn r#return(should_return_value: bool) -> Instruction {
-        let mut instruction = Instruction(Operation::Return as u32);
-
-        instruction.set_b_to_boolean(should_return_value);
-
-        instruction
-    }
-
-    pub fn operation(&self) -> Operation {
-        Operation::from((self.0 & 0b0000_0000_0011_1111) as u8)
-    }
-
-    pub fn set_operation(&mut self, operation: Operation) {
-        self.0 |= u8::from(operation) as u32;
-    }
-
-    pub fn data(&self) -> (Operation, u8, u8, u8, bool, bool) {
-        (
-            self.operation(),
-            self.a(),
-            self.b(),
-            self.c(),
-            self.b_is_constant(),
-            self.c_is_constant(),
-        )
-    }
-
-    pub fn a(&self) -> u8 {
-        (self.0 >> 24) as u8
-    }
-
-    pub fn b(&self) -> u8 {
-        (self.0 >> 16) as u8
-    }
-
-    pub fn c(&self) -> u8 {
-        (self.0 >> 8) as u8
-    }
-
-    pub fn a_as_boolean(&self) -> bool {
-        self.a() != 0
-    }
-
-    pub fn b_as_boolean(&self) -> bool {
-        self.b() != 0
-    }
-
-    pub fn c_as_boolean(&self) -> bool {
-        self.c() != 0
-    }
-
-    pub fn set_a_to_boolean(&mut self, boolean: bool) -> &mut Self {
-        self.set_a(if boolean { 1 } else { 0 });
-
-        self
-    }
-
-    pub fn set_b_to_boolean(&mut self, boolean: bool) -> &mut Self {
-        self.set_b(if boolean { 1 } else { 0 });
-
-        self
-    }
-
-    pub fn set_c_to_boolean(&mut self, boolean: bool) -> &mut Self {
-        self.set_c(if boolean { 1 } else { 0 });
-
-        self
-    }
-
-    pub fn set_a(&mut self, to_register: u8) {
-        self.0 |= (to_register as u32) << 24;
-    }
-
-    pub fn set_b(&mut self, argument: u8) {
-        self.0 |= (argument as u32) << 16;
-    }
-
-    pub fn set_c(&mut self, argument: u8) {
-        self.0 |= (argument as u32) << 8;
-    }
-
-    pub fn b_is_constant(&self) -> bool {
-        self.0 & 0b1000_0000 != 0
-    }
-
-    pub fn c_is_constant(&self) -> bool {
-        self.0 & 0b0100_0000 != 0
-    }
-
-    pub fn set_b_is_constant(&mut self) -> &mut Self {
-        self.0 |= 0b1000_0000;
-
-        self
-    }
-
-    pub fn set_c_is_constant(&mut self) -> &mut Self {
-        self.0 |= 0b0100_0000;
-
-        self
-    }
-
-    pub fn yields_value(&self) -> bool {
-        match self.operation() {
-            Operation::Add
-            | Operation::Call
-            | Operation::Divide
-            | Operation::GetLocal
-            | Operation::LoadBoolean
-            | Operation::LoadConstant
-            | Operation::LoadList
-            | Operation::LoadSelf
-            | Operation::Modulo
-            | Operation::Multiply
-            | Operation::Negate
-            | Operation::Not
-            | Operation::Subtract => true,
-            Operation::CallNative => {
-                let native_function = NativeFunction::from(self.b());
-
-                native_function.r#type().return_type.is_some()
-            }
-            _ => false,
-        }
-    }
-
-    pub fn yielded_type(&self, chunk: &Chunk) -> Option<Type> {
-        use Operation::*;
-
-        match self.operation() {
-            Add | Divide | Modulo | Multiply | Subtract => {
-                if self.b_is_constant() {
-                    chunk.get_constant_type(self.b())
-                } else {
-                    chunk.get_register_type(self.b())
-                }
-            }
-            LoadBoolean | Not => Some(Type::Boolean),
-            Negate => {
-                if self.b_is_constant() {
-                    chunk.get_constant_type(self.b())
-                } else {
-                    chunk.get_register_type(self.b())
-                }
-            }
-            LoadConstant => chunk.get_constant_type(self.b()),
-            LoadList => chunk.get_register_type(self.a()),
-            GetLocal => chunk.get_local_type(self.b()),
-            CallNative => {
-                let native_function = NativeFunction::from(self.b());
-
-                native_function.r#type().return_type.map(|boxed| *boxed)
-            }
-            _ => None,
-        }
-    }
-
-    pub fn disassembly_info(&self, chunk: &Chunk) -> String {
-        let format_arguments = || {
-            let first_argument = if self.b_is_constant() {
-                format!("C{}", self.b())
-            } else {
-                format!("R{}", self.b())
-            };
-            let second_argument = if self.c_is_constant() {
-                format!("C{}", self.c())
-            } else {
-                format!("R{}", self.c())
-            };
-
-            (first_argument, second_argument)
-        };
-
-        match self.operation() {
-            Operation::Move => format!("R{} = R{}", self.a(), self.b()),
-            Operation::Close => {
-                let from_register = self.b();
-                let to_register = self.c().saturating_sub(1);
-
-                format!("R{from_register}..=R{to_register}")
-            }
-            Operation::LoadBoolean => {
-                let to_register = self.a();
-                let boolean = self.b_as_boolean();
-                let jump = self.c_as_boolean();
-
-                if jump {
-                    format!("R{to_register} = {boolean} && SKIP")
-                } else {
-                    format!("R{to_register} = {boolean}")
-                }
-            }
-            Operation::LoadConstant => {
-                let register_index = self.a();
-                let constant_index = self.b();
-                let jump = self.c_as_boolean();
-
-                if jump {
-                    format!("R{register_index} = C{constant_index} && SKIP")
-                } else {
-                    format!("R{register_index} = C{constant_index}")
-                }
-            }
-            Operation::LoadList => {
-                let to_register = self.a();
-                let first_index = self.b();
-                let last_index = self.c();
-
-                format!("R{to_register} = [R{first_index}..=R{last_index}]",)
-            }
-            Operation::LoadSelf => {
-                let to_register = self.a();
-                let name = chunk
-                    .name()
-                    .map(|idenifier| idenifier.as_str())
-                    .unwrap_or("self");
-
-                format!("R{to_register} = {name}")
-            }
-            Operation::DefineLocal => {
-                let to_register = self.a();
-                let local_index = self.b();
-                let identifier_display = match chunk.get_identifier(local_index) {
-                    Some(identifier) => identifier.to_string(),
-                    None => "???".to_string(),
-                };
-                let mutable_display = if self.c_as_boolean() { "mut" } else { "" };
-
-                format!("R{to_register} = L{local_index} {mutable_display} {identifier_display}")
-            }
-            Operation::GetLocal => {
-                let local_index = self.b();
-
-                format!("R{} = L{}", self.a(), local_index)
-            }
-            Operation::SetLocal => {
-                let local_index = self.b();
-                let identifier_display = match chunk.get_identifier(local_index) {
-                    Some(identifier) => identifier.to_string(),
-                    None => "???".to_string(),
-                };
-
-                format!("L{} = R{} {}", local_index, self.a(), identifier_display)
-            }
-            Operation::Add => {
-                let to_register = self.a();
-                let (first_argument, second_argument) = format_arguments();
-
-                format!("R{to_register} = {first_argument} + {second_argument}",)
-            }
-            Operation::Subtract => {
-                let to_register = self.a();
-                let (first_argument, second_argument) = format_arguments();
-
-                format!("R{to_register} = {first_argument} - {second_argument}",)
-            }
-            Operation::Multiply => {
-                let to_register = self.a();
-                let (first_argument, second_argument) = format_arguments();
-
-                format!("R{to_register} = {first_argument} * {second_argument}",)
-            }
-            Operation::Divide => {
-                let to_register = self.a();
-                let (first_argument, second_argument) = format_arguments();
-
-                format!("R{to_register} = {first_argument} / {second_argument}",)
-            }
-            Operation::Modulo => {
-                let to_register = self.a();
-                let (first_argument, second_argument) = format_arguments();
-
-                format!("R{to_register} = {first_argument} % {second_argument}",)
-            }
-            Operation::Test => {
-                let to_register = self.a();
-                let test_value = self.c_as_boolean();
-
-                format!("if R{to_register} != {test_value} {{ SKIP }}")
-            }
-            Operation::TestSet => {
-                let to_register = self.a();
-                let argument = format!("R{}", self.b());
-                let test_value = self.c_as_boolean();
-                let bang = if test_value { "" } else { "!" };
-
-                format!("if {bang}R{to_register} {{ R{to_register} = R{argument} }}",)
-            }
-            Operation::Equal => {
-                let comparison_symbol = if self.a_as_boolean() { "==" } else { "!=" };
-
-                let (first_argument, second_argument) = format_arguments();
-
-                format!("if {first_argument} {comparison_symbol} {second_argument} {{ SKIP }}")
-            }
-            Operation::Less => {
-                let comparison_symbol = if self.a_as_boolean() { "<" } else { ">=" };
-                let (first_argument, second_argument) = format_arguments();
-
-                format!("if {first_argument} {comparison_symbol} {second_argument} {{ SKIP }}")
-            }
-            Operation::LessEqual => {
-                let comparison_symbol = if self.a_as_boolean() { "<=" } else { ">" };
-                let (first_argument, second_argument) = format_arguments();
-
-                format!("if {first_argument} {comparison_symbol} {second_argument} {{ SKIP }}")
-            }
-            Operation::Negate => {
-                let to_register = self.a();
-                let argument = if self.b_is_constant() {
-                    format!("C{}", self.b())
-                } else {
-                    format!("R{}", self.b())
-                };
-
-                format!("R{to_register} = -{argument}")
-            }
-            Operation::Not => {
-                let to_register = self.a();
-                let argument = if self.b_is_constant() {
-                    format!("C{}", self.b())
-                } else {
-                    format!("R{}", self.b())
-                };
-
-                format!("R{to_register} = !{argument}")
-            }
-            Operation::Jump => {
-                let jump_distance = self.b();
-                let is_positive = self.c_as_boolean();
-
-                if is_positive {
-                    format!("JUMP +{jump_distance}")
-                } else {
-                    format!("JUMP -{jump_distance}")
-                }
-            }
-            Operation::Call => {
-                let to_register = self.a();
-                let function_register = self.b();
-                let argument_count = self.c();
-
-                let mut output = format!("R{to_register} = R{function_register}(");
-
-                if argument_count != 0 {
-                    let first_argument = function_register + 1;
-
-                    for (index, register) in
-                        (first_argument..first_argument + argument_count).enumerate()
-                    {
-                        if index > 0 {
-                            output.push_str(", ");
-                        }
-
-                        output.push_str(&format!("R{}", register));
-                    }
-                }
-
-                output.push(')');
-
-                output
-            }
-            Operation::CallNative => {
-                let to_register = self.a();
-                let native_function = NativeFunction::from(self.b());
-                let argument_count = self.c();
-                let mut output = String::new();
-                let native_function_name = native_function.as_str();
-
-                if native_function.r#type().return_type.is_some() {
-                    output.push_str(&format!("R{} = {}(", to_register, native_function_name));
-                } else {
-                    output.push_str(&format!("{}(", native_function_name));
-                }
-
-                if argument_count != 0 {
-                    let first_argument = to_register.saturating_sub(argument_count);
-
-                    for (index, register) in (first_argument..to_register).enumerate() {
-                        if index > 0 {
-                            output.push_str(", ");
-                        }
-
-                        output.push_str(&format!("R{}", register));
-                    }
-                }
-
-                output.push(')');
-
-                output
-            }
-            Operation::Return => {
-                let should_return_value = self.b_as_boolean();
-
-                if should_return_value {
-                    "->".to_string()
-                } else {
-                    "".to_string()
-                }
-            }
-        }
-    }
-}
-
-impl From<&Instruction> for u32 {
-    fn from(instruction: &Instruction) -> Self {
-        instruction.0
-    }
-}
-
-#[cfg(test)]
-mod tests {
-    use super::*;
-
-    #[test]
-    fn r#move() {
-        let mut instruction = Instruction::r#move(0, 1);
-
-        instruction.set_b_is_constant();
-        instruction.set_c_is_constant();
-
-        assert_eq!(instruction.operation(), Operation::Move);
-        assert_eq!(instruction.a(), 0);
-        assert_eq!(instruction.b(), 1);
-        assert!(instruction.b_is_constant());
-        assert!(instruction.b_is_constant());
-    }
-
-    #[test]
-    fn close() {
-        let instruction = Instruction::close(1, 2);
-
-        assert_eq!(instruction.operation(), Operation::Close);
-        assert_eq!(instruction.b(), 1);
-        assert_eq!(instruction.c(), 2);
-    }
-
-    #[test]
-    fn load_boolean() {
-        let instruction = Instruction::load_boolean(4, true, true);
-
-        assert_eq!(instruction.operation(), Operation::LoadBoolean);
-        assert_eq!(instruction.a(), 4);
-        assert!(instruction.a_as_boolean());
-        assert!(instruction.c_as_boolean());
-    }
-
-    #[test]
-    fn load_constant() {
-        let mut instruction = Instruction::load_constant(0, 1, true);
-
-        instruction.set_b_is_constant();
-        instruction.set_c_is_constant();
-
-        assert_eq!(instruction.operation(), Operation::LoadConstant);
-        assert_eq!(instruction.a(), 0);
-        assert_eq!(instruction.b(), 1);
-        assert!(instruction.b_is_constant());
-        assert!(instruction.b_is_constant());
-        assert!(instruction.c_as_boolean());
-    }
-
-    #[test]
-    fn load_list() {
-        let instruction = Instruction::load_list(0, 1);
-
-        assert_eq!(instruction.operation(), Operation::LoadList);
-        assert_eq!(instruction.a(), 0);
-        assert_eq!(instruction.b(), 1);
-    }
-
-    #[test]
-    fn load_self() {
-        let instruction = Instruction::load_self(10);
-
-        assert_eq!(instruction.operation(), Operation::LoadSelf);
-        assert_eq!(instruction.a(), 10);
-    }
-
-    #[test]
-    fn declare_local() {
-        let mut instruction = Instruction::define_local(0, 1, true);
-
-        instruction.set_b_is_constant();
-
-        assert_eq!(instruction.operation(), Operation::DefineLocal);
-        assert_eq!(instruction.a(), 0);
-        assert_eq!(instruction.b(), 1);
-        assert_eq!(instruction.c(), true as u8);
-        assert!(instruction.b_is_constant());
-    }
-
-    #[test]
-    fn add() {
-        let mut instruction = Instruction::add(1, 1, 0);
-
-        instruction.set_b_is_constant();
-
-        assert_eq!(instruction.operation(), Operation::Add);
-        assert_eq!(instruction.a(), 1);
-        assert_eq!(instruction.b(), 1);
-        assert_eq!(instruction.c(), 0);
-        assert!(instruction.b_is_constant());
-    }
-
-    #[test]
-    fn subtract() {
-        let mut instruction = Instruction::subtract(0, 1, 2);
-
-        instruction.set_b_is_constant();
-        instruction.set_c_is_constant();
-
-        assert_eq!(instruction.operation(), Operation::Subtract);
-        assert_eq!(instruction.a(), 0);
-        assert_eq!(instruction.b(), 1);
-        assert_eq!(instruction.c(), 2);
-        assert!(instruction.b_is_constant());
-        assert!(instruction.b_is_constant());
-    }
-
-    #[test]
-    fn multiply() {
-        let mut instruction = Instruction::multiply(0, 1, 2);
-
-        instruction.set_b_is_constant();
-        instruction.set_c_is_constant();
-
-        assert_eq!(instruction.operation(), Operation::Multiply);
-        assert_eq!(instruction.a(), 0);
-        assert_eq!(instruction.b(), 1);
-        assert_eq!(instruction.c(), 2);
-        assert!(instruction.b_is_constant());
-        assert!(instruction.b_is_constant());
-    }
-
-    #[test]
-    fn divide() {
-        let mut instruction = Instruction::divide(0, 1, 2);
-
-        instruction.set_b_is_constant();
-        instruction.set_c_is_constant();
-
-        assert_eq!(instruction.operation(), Operation::Divide);
-        assert_eq!(instruction.a(), 0);
-        assert_eq!(instruction.b(), 1);
-        assert_eq!(instruction.c(), 2);
-        assert!(instruction.b_is_constant());
-        assert!(instruction.b_is_constant());
-    }
-
-    #[test]
-    fn and() {
-        let instruction = Instruction::test(4, true);
-
-        assert_eq!(instruction.operation(), Operation::Test);
-        assert_eq!(instruction.a(), 4);
-        assert!(instruction.c_as_boolean());
-    }
-
-    #[test]
-    fn or() {
-        let instruction = Instruction::test_set(4, 1, true);
-
-        assert_eq!(instruction.operation(), Operation::TestSet);
-        assert_eq!(instruction.a(), 4);
-        assert_eq!(instruction.b(), 1);
-        assert!(instruction.c_as_boolean());
-    }
-
-    #[test]
-    fn equal() {
-        let mut instruction = Instruction::equal(true, 1, 2);
-
-        instruction.set_b_is_constant();
-        instruction.set_c_is_constant();
-
-        assert_eq!(instruction.operation(), Operation::Equal);
-        assert!(instruction.a_as_boolean());
-        assert_eq!(instruction.b(), 1);
-        assert_eq!(instruction.c(), 2);
-        assert!(instruction.b_is_constant());
-        assert!(instruction.b_is_constant());
-    }
-
-    #[test]
-    fn negate() {
-        let mut instruction = Instruction::negate(0, 1);
-
-        instruction.set_b_is_constant();
-        instruction.set_c_is_constant();
-
-        assert_eq!(instruction.operation(), Operation::Negate);
-        assert_eq!(instruction.a(), 0);
-        assert_eq!(instruction.b(), 1);
-        assert!(instruction.b_is_constant());
-        assert!(instruction.b_is_constant());
-    }
-
-    #[test]
-    fn not() {
-        let mut instruction = Instruction::not(0, 1);
-
-        instruction.set_b_is_constant();
-        instruction.set_c_is_constant();
-
-        assert_eq!(instruction.operation(), Operation::Not);
-        assert_eq!(instruction.a(), 0);
-        assert_eq!(instruction.b(), 1);
-        assert!(instruction.b_is_constant());
-        assert!(instruction.b_is_constant());
-    }
-
-    #[test]
-    fn jump() {
-        let instruction = Instruction::jump(4, true);
-
-        assert_eq!(instruction.operation(), Operation::Jump);
-
-        assert_eq!(instruction.b(), 4);
-        assert!(instruction.c_as_boolean());
-    }
-
-    #[test]
-    fn call() {
-        let instruction = Instruction::call(1, 3, 4);
-
-        assert_eq!(instruction.operation(), Operation::Call);
-        assert_eq!(instruction.a(), 1);
-        assert_eq!(instruction.b(), 3);
-        assert_eq!(instruction.c(), 4);
-    }
-
-    #[test]
-    fn r#return() {
-        let instruction = Instruction::r#return(true);
-
-        assert_eq!(instruction.operation(), Operation::Return);
-        assert!(instruction.b_as_boolean());
-    }
-}

dust-lang/src/lib.rs

@@ -1,44 +0,0 @@
-//! The Dust programming language library.
-
-pub mod chunk;
-pub mod compiler;
-pub mod disassembler;
-pub mod dust_error;
-pub mod formatter;
-pub mod instruction;
-pub mod lexer;
-pub mod native_function;
-pub mod operation;
-pub mod optimizer;
-pub mod token;
-pub mod r#type;
-pub mod value;
-pub mod vm;
-
-pub use crate::chunk::{Chunk, ChunkError, Local, Scope};
-pub use crate::compiler::{compile, CompileError, Compiler};
-pub use crate::disassembler::Disassembler;
-pub use crate::dust_error::{AnnotatedError, DustError};
-pub use crate::formatter::{format, Formatter};
-pub use crate::instruction::Instruction;
-pub use crate::lexer::{lex, LexError, Lexer};
-pub use crate::native_function::{NativeFunction, NativeFunctionError};
-pub use crate::operation::Operation;
-pub use crate::optimizer::{optimize, Optimizer};
-pub use crate::r#type::{EnumType, FunctionType, RangeableType, StructType, Type, TypeConflict};
-pub use crate::token::{Token, TokenKind, TokenOwned};
-pub use crate::value::{ConcreteValue, Function, Value, ValueError};
-pub use crate::vm::{run, Vm, VmError};
-
-use std::fmt::Display;
-
-use serde::{Deserialize, Serialize};
-
-#[derive(Clone, Copy, Debug, Eq, PartialEq, PartialOrd, Ord, Hash, Serialize, Deserialize)]
-pub struct Span(pub usize, pub usize);
-
-impl Display for Span {
-    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
-        write!(f, "({}, {})", self.0, self.1)
-    }
-}

dust-lang/src/native_function.rs

@@ -1,418 +0,0 @@
-//! Built-in functions that implement extended functionality.
-//!
-//! Native functions are used either to implement features that are not possible to implement in
-//! Dust itself or that are more efficient to implement in Rust.
-use std::{
-    fmt::{self, Display, Formatter},
-    io::{self, stdin, stdout, Write},
-    string::{self},
-};
-
-use serde::{Deserialize, Serialize};
-
-use crate::{
-    AnnotatedError, ConcreteValue, FunctionType, Instruction, Span, Type, Value, Vm, VmError,
-};
-
-macro_rules! define_native_function {
-    ($(($name:ident, $byte:literal, $str:expr, $type:expr)),*) => {
-        /// A dust-native function.
-        ///
-        /// See the [module-level documentation](index.html) for more information.
-        #[derive(Clone, Debug, Eq, PartialEq, PartialOrd, Ord, Serialize, Deserialize)]
-        pub enum NativeFunction {
-            $(
-                $name = $byte as isize,
-            )*
-        }
-
-        impl NativeFunction {
-            pub fn as_str(&self) -> &'static str {
-                match self {
-                    $(
-                        NativeFunction::$name => $str,
-                    )*
-                }
-            }
-
-            #[allow(clippy::should_implement_trait)]
-            pub fn from_str(string: &str) -> Option<Self> {
-                match string {
-                    $(
-                        $str => Some(NativeFunction::$name),
-                    )*
-                    _ => None,
-                }
-            }
-
-            pub fn r#type(&self) -> FunctionType {
-                match self {
-                    $(
-                        NativeFunction::$name => $type,
-                    )*
-                }
-            }
-
-            pub fn returns_value(&self) -> bool {
-                match self {
-                    $(
-                        NativeFunction::$name => $type.return_type.is_some(),
-                    )*
-                }
-            }
-        }
-
-        impl From<u8> for NativeFunction {
-            fn from(byte: u8) -> Self {
-                match byte {
-                    $(
-                        $byte => NativeFunction::$name,
-                    )*
-                    _ => {
-                        if cfg!(test) {
-                            panic!("Invalid native function byte: {}", byte)
-                        } else {
-                            NativeFunction::Panic
-                        }
-                    }
-                }
-            }
-        }
-
-        impl From<NativeFunction> for u8 {
-            fn from(native_function: NativeFunction) -> Self {
-                match native_function {
-                    $(
-                        NativeFunction::$name => $byte,
-                    )*
-                }
-            }
-        }
-    };
-}
-
-define_native_function! {
-    // Assertion
-    (
-        Assert,
-        0_u8,
-        "assert",
-        FunctionType {
-            type_parameters: None,
-            value_parameters: None,
-            return_type: None
-        }
-    ),
-    // (AssertEqual, 1_u8, "assert_equal", false),
-    // (AssertNotEqual, 2_u8, "assert_not_equal", false),
-    (
-        Panic,
-        3_u8,
-        "panic",
-        FunctionType {
-            type_parameters: None,
-            value_parameters: None,
-            return_type: Some(Box::new(Type::Any))
-        }
-    ),
-
-    // // Type conversion
-    // (Parse, 4_u8, "parse", true),
-    // (ToByte, 5_u8, "to_byte", true),
-    // (ToFloat, 6_u8, "to_float", true),
-    // (ToInteger, 7_u8, "to_integer", true),
-    (
-        ToString,
-        8_u8,
-        "to_string",
-        FunctionType {
-            type_parameters: None,
-            value_parameters: Some(vec![(0, Type::Any)]),
-            return_type: Some(Box::new(Type::String { length: None }))
-        }
-    ),
-
-    // // List and string
-    // (All, 9_u8, "all", true),
-    // (Any, 10_u8, "any", true),
-    // (Append, 11_u8, "append", false),
-    // (Contains, 12_u8, "contains", true),
-    // (Dedup, 13_u8, "dedup", false),
-    // (EndsWith, 14_u8, "ends_with", true),
-    // (Find, 15_u8, "find", true),
-    // (Get, 16_u8, "get", true),
-    // (IndexOf, 17_u8, "index_of", true),
-    // (Length, 18_u8, "length", true),
-    // (Prepend, 19_u8, "prepend", false),
-    // (Replace, 20_u8, "replace", false),
-    // (Set, 21_u8, "set", false),
-    // (StartsWith, 22_u8, "starts_with", true),
-    // (Slice, 23_u8, "slice", true),
-    // (Sort, 24_u8, "sort", false),
-    // (Split, 25_u8, "split", true),
-
-    // // List
-    // (Flatten, 26_u8, "flatten", false),
-    // (Join, 27_u8, "join", true),
-    // (Map, 28_u8, "map", true),
-    // (Reduce, 29_u8, "reduce", true),
-    // (Remove, 30_u8, "remove", false),
-    // (Reverse, 31_u8, "reverse", false),
-    // (Unzip, 32_u8, "unzip", true),
-    // (Zip, 33_u8, "zip", true),
-
-    // // String
-    // (Bytes, 34_u8, "bytes", true),
-    // (CharAt, 35_u8, "char_at", true),
-    // (CharCodeAt, 36_u8, "char_code_at", true),
-    // (Chars, 37_u8, "chars", true),
-    // (Format, 38_u8, "format", true),
-    // (Repeat, 39_u8, "repeat", true),
-    // (SplitAt, 40_u8, "split_at", true),
-    // (SplitLines, 41_u8, "split_lines", true),
-    // (SplitWhitespace, 42_u8, "split_whitespace", true),
-    // (ToLowerCase, 43_u8, "to_lower_case", true),
-    // (ToUpperCase, 44_u8, "to_upper_case", true),
-    // (Trim, 45_u8, "trim", true),
-    // (TrimEnd, 46_u8, "trim_end", true),
-    // (TrimStart, 47_u8, "trim_start", true),
-
-    // // I/O
-    // // Read
-    // (Read, 48_u8, "read", true),
-    // (ReadFile, 49_u8, "read_file", true),
-    (
-        ReadLine,
-        50_u8,
-        "read_line",
-        FunctionType {
-            type_parameters: None,
-            value_parameters: None,
-            return_type: Some(Box::new(Type::String { length: None }))
-        }
-    ),
-    // (ReadTo, 51_u8, "read_to", false),
-    // (ReadUntil, 52_u8, "read_until", true),
-    // // Write
-    // (AppendFile, 53_u8, "append_file", false),
-    // (PrependFile, 54_u8, "prepend_file", false),
-    (
-        Write,
-        55_u8,
-        "write",
-        FunctionType {
-            type_parameters: None,
-            value_parameters: Some(vec![(0, Type::String { length: None })]),
-            return_type: None
-        }
-    ),
-    // (WriteFile, 56_u8, "write_file", false),
-    (
-        WriteLine,
-        57_u8,
-        "write_line",
-        FunctionType {
-            type_parameters: None,
-            value_parameters: Some(vec![(0, Type::String { length: None })]),
-            return_type: None
-        }
-    )
-
-    // // Random
-    // (Random, 58_u8, "random", true),
-    // (RandomInRange, 59_u8, "random_in_range", true)
-}
-
-impl NativeFunction {
-    pub fn call(
-        &self,
-        instruction: Instruction,
-        vm: &Vm,
-        position: Span,
-    ) -> Result<Option<Value>, VmError> {
-        let to_register = instruction.a();
-        let argument_count = instruction.c();
-
-        let return_value = match self {
-            NativeFunction::Panic => {
-                let message = if argument_count == 0 {
-                    None
-                } else {
-                    let mut message = String::new();
-
-                    for argument_index in 0..argument_count {
-                        if argument_index != 0 {
-                            message.push(' ');
-                        }
-
-                        let argument = vm.open_register(argument_index, position)?;
-
-                        message.push_str(&argument.to_string());
-                    }
-
-                    Some(message)
-                };
-
-                return Err(VmError::NativeFunction(NativeFunctionError::Panic {
-                    message,
-                    position,
-                }));
-            }
-
-            // Type conversion
-            NativeFunction::ToString => {
-                let mut string = String::new();
-
-                for argument_index in 0..argument_count {
-                    let argument = vm.open_register(argument_index, position)?;
-
-                    string.push_str(&argument.to_string());
-                }
-
-                Some(Value::Concrete(ConcreteValue::String(string)))
-            }
-
-            // I/O
-            NativeFunction::ReadLine => {
-                let mut buffer = String::new();
-
-                stdin().read_line(&mut buffer).map_err(|io_error| {
-                    VmError::NativeFunction(NativeFunctionError::Io {
-                        error: io_error.kind(),
-                        position,
-                    })
-                })?;
-
-                buffer = buffer.trim_end_matches('\n').to_string();
-
-                Some(Value::Concrete(ConcreteValue::String(buffer)))
-            }
-            NativeFunction::Write => {
-                let to_register = instruction.a();
-                let mut stdout = stdout();
-                let map_err = |io_error: io::Error| {
-                    VmError::NativeFunction(NativeFunctionError::Io {
-                        error: io_error.kind(),
-                        position,
-                    })
-                };
-
-                let first_argument = to_register.saturating_sub(argument_count);
-                let last_argument = to_register.saturating_sub(1);
-
-                for argument_index in first_argument..=last_argument {
-                    if argument_index != first_argument {
-                        stdout.write(b" ").map_err(map_err)?;
-                    }
-
-                    let argument_string = vm.open_register(argument_index, position)?.to_string();
-
-                    stdout
-                        .write_all(argument_string.as_bytes())
-                        .map_err(map_err)?;
-                }
-
-                None
-            }
-            NativeFunction::WriteLine => {
-                let mut stdout = stdout();
-                let map_err = |io_error: io::Error| {
-                    VmError::NativeFunction(NativeFunctionError::Io {
-                        error: io_error.kind(),
-                        position,
-                    })
-                };
-
-                let first_index = to_register.saturating_sub(argument_count);
-                let arguments = vm.open_nonempty_registers(first_index..to_register, position)?;
-
-                for (index, argument) in arguments.into_iter().enumerate() {
-                    if index != 0 {
-                        stdout.write(b" ").map_err(map_err)?;
-                    }
-
-                    if let Value::Concrete(ConcreteValue::String(string)) = argument {
-                        let bytes = string.as_bytes();
-
-                        stdout.write_all(bytes).map_err(map_err)?;
-                    } else {
-                        let bytes = argument.to_string().into_bytes();
-
-                        stdout.write_all(&bytes).map_err(map_err)?;
-                    }
-                }
-
-                stdout.write(b"\n").map_err(map_err)?;
-
-                None
-            }
-            _ => todo!(),
-        };
-
-        Ok(return_value)
-    }
-}
-
-impl Display for NativeFunction {
-    fn fmt(&self, f: &mut Formatter) -> fmt::Result {
-        write!(f, "{}", self.as_str())
-    }
-}
-
-#[derive(Debug, Clone, PartialEq)]
-pub enum NativeFunctionError {
-    ExpectedArgumentCount {
-        expected: usize,
-        found: usize,
-        position: Span,
-    },
-    Panic {
-        message: Option<String>,
-        position: Span,
-    },
-    Parse {
-        error: string::ParseError,
-        position: Span,
-    },
-    Io {
-        error: io::ErrorKind,
-        position: Span,
-    },
-}
-
-impl AnnotatedError for NativeFunctionError {
-    fn title() -> &'static str {
-        "Native Function Error"
-    }
-
-    fn description(&self) -> &'static str {
-        match self {
-            NativeFunctionError::ExpectedArgumentCount { .. } => {
-                "Expected a different number of arguments"
-            }
-            NativeFunctionError::Panic { .. } => "Explicit panic",
-            NativeFunctionError::Parse { .. } => "Failed to parse value",
-            NativeFunctionError::Io { .. } => "I/O error",
-        }
-    }
-
-    fn details(&self) -> Option<String> {
-        match self {
-            NativeFunctionError::ExpectedArgumentCount {
-                expected, found, ..
-            } => Some(format!("Expected {} arguments, found {}", expected, found)),
-            NativeFunctionError::Panic { message, .. } => message.clone(),
-            NativeFunctionError::Parse { error, .. } => Some(format!("{}", error)),
-            NativeFunctionError::Io { error, .. } => Some(format!("{}", error)),
-        }
-    }
-
-    fn position(&self) -> Span {
-        match self {
-            NativeFunctionError::ExpectedArgumentCount { position, .. } => *position,
-            NativeFunctionError::Panic { position, .. } => *position,
-            NativeFunctionError::Parse { position, .. } => *position,
-            NativeFunctionError::Io { position, .. } => *position,
-        }
-    }
-}

dust-lang/src/operation.rs

@@ -1,110 +0,0 @@
-//! Part of an [Instruction][crate::Instruction], which can be executed by the Dust virtual machine.
-//!
-//! !!! Warning !!!
-//! The byte values of the operations matter. The seventh and eighth bits must be zero so that the
-//! [Instruction][crate::Instruction] type can use them as flags.
-
-use std::fmt::{self, Display, Formatter};
-
-macro_rules! define_operation {
-    ($(($name:ident, $byte:literal, $str:expr, $type:expr)),*) => {
-        /// Part of an [Instruction][crate::Instruction], which can be executed by the Dust virtual machine.)
-        ///
-        /// See the [module-level documentation](index.html) for more information.
-        #[derive(Clone, Copy, Debug, PartialEq)]
-        pub enum Operation {
-            $(
-                $name = $byte as isize,
-            )*
-        }
-
-        impl From<u8> for Operation {
-            fn from(byte: u8) -> Self {
-                match byte {
-                    $(
-                        $byte => Operation::$name,
-                    )*
-                    _ => {
-                        if cfg!(test) {
-                            panic!("Invalid operation byte: {}", byte)
-                        } else {
-                            Operation::Return
-                        }
-                    }
-                }
-            }
-        }
-
-        impl From<Operation> for u8 {
-            fn from(operation: Operation) -> Self {
-                match operation {
-                    $(
-                        Operation::$name => $byte,
-                    )*
-                }
-            }
-        }
-
-        impl Display for Operation {
-            fn fmt(&self, f: &mut Formatter) -> fmt::Result {
-                match self {
-                    $(
-                        Operation::$name => write!(f, "{}", $str),
-                    )*
-                }
-            }
-        }
-    }
-}
-
-define_operation! {
-    (Move, 0b0000_0000, "MOVE", None),
-    (Close, 0b000_0001, "CLOSE", None),
-    (LoadBoolean, 0b0000_0010, "LOAD_BOOLEAN", None),
-    (LoadConstant, 0b0000_0011, "LOAD_CONSTANT", None),
-    (LoadList, 0b0000_0100, "LOAD_LIST", None),
-    (LoadSelf, 0b0000_0101, "LOAD_SELF", None),
-    (DefineLocal, 0b0000_0110, "DEFINE_LOCAL", None),
-    (GetLocal, 0b0000_0111, "GET_LOCAL", None),
-    (SetLocal, 0b0000_1000, "SET_LOCAL", None),
-    (Add, 0b0000_1001, "ADD", None),
-    (Subtract, 0b0000_1010, "SUBTRACT", None),
-    (Multiply, 0b0000_1011, "MULTIPLY", None),
-    (Divide, 0b0000_1100, "DIVIDE", None),
-    (Modulo, 0b0000_1101, "MODULO", None),
-    (Test, 0b0000_1110, "TEST", None),
-    (TestSet, 0b0000_1111, "TEST_SET", None),
-    (Equal, 0b0001_0000, "EQUAL", None),
-    (Less, 0b0001_0001, "LESS", None),
-    (LessEqual, 0b0001_0010, "LESS_EQUAL", None),
-    (Negate, 0b0001_0011, "NEGATE", None),
-    (Not, 0b0001_0100, "NOT", None),
-    (Jump, 0b0001_0101, "JUMP", None),
-    (Call, 0b0001_0110, "CALL", None),
-    (CallNative, 0b0001_0111, "CALL_NATIVE", None),
-    (Return, 0b0001_1000, "RETURN", None)
-}
-
-impl Operation {
-    pub fn is_math(&self) -> bool {
-        matches!(
-            self,
-            Operation::Add
-                | Operation::Subtract
-                | Operation::Multiply
-                | Operation::Divide
-                | Operation::Modulo
-        )
-    }
-
-    pub fn is_comparison(&self) -> bool {
-        matches!(
-            self,
-            Operation::Equal | Operation::Less | Operation::LessEqual
-        )
-    }
-
-    pub fn is_test(&self) -> bool {
-        matches!(self, Operation::Test | Operation::TestSet)
-    }
-}

dust-lang/src/optimizer.rs

@@ -1,96 +0,0 @@
-//! Tools used by the compiler to optimize a chunk's bytecode.
-use std::{iter::Map, slice::Iter};
-
-use crate::{Instruction, Operation, Span};
-
-type MapToOperation = fn(&(Instruction, Span)) -> Operation;
-
-type OperationIter<'iter> = Map<Iter<'iter, (Instruction, Span)>, MapToOperation>;
-
-/// Performs optimizations on a subset of instructions.
-pub fn optimize(instructions: &mut [(Instruction, Span)]) -> usize {
-    Optimizer::new(instructions).optimize()
-}
-
-/// An instruction optimizer that mutably borrows instructions from a chunk.
-#[derive(Debug, Eq, PartialEq, PartialOrd, Ord)]
-pub struct Optimizer<'chunk> {
-    instructions: &'chunk mut [(Instruction, Span)],
-}
-
-impl<'chunk> Optimizer<'chunk> {
-    /// Creates a new optimizer with a mutable reference to some of a chunk's instructions.
-    pub fn new(instructions: &'chunk mut [(Instruction, Span)]) -> Self {
-        Self { instructions }
-    }
-
-    /// Potentially mutates the instructions to optimize them.
-    pub fn optimize(&mut self) -> usize {
-        let mut optimizations = 0;
-
-        if matches!(
-            self.get_operations(),
-            Some([
-                Operation::Equal | Operation::Less | Operation::LessEqual,
-                Operation::Jump,
-                Operation::LoadBoolean | Operation::LoadConstant,
-                Operation::LoadBoolean | Operation::LoadConstant,
-            ])
-        ) {
-            self.optimize_comparison();
-
-            optimizations += 1;
-        }
-
-        optimizations
-    }
-
-    /// Optimizes a comparison operation.
-    ///
-    /// The instructions must be in the following order:
-    ///     - `Operation::Equal | Operation::Less | Operation::LessEqual`
-    ///     - `Operation::Jump`
-    ///     - `Operation::LoadBoolean | Operation::LoadConstant`
-    ///     - `Operation::LoadBoolean | Operation::LoadConstant`
-    fn optimize_comparison(&mut self) {
-        log::debug!("Optimizing comparison");
-
-        let first_loader_register = {
-            let first_loader = &mut self.instructions[2].0;
-
-            first_loader.set_c_to_boolean(true);
-            first_loader.a()
-        };
-
-        let second_loader = &mut self.instructions[3].0;
-        let mut second_loader_new = Instruction::with_operation(second_loader.operation());
-
-        second_loader_new.set_a(first_loader_register);
-        second_loader_new.set_b(second_loader.b());
-        second_loader_new.set_c(second_loader.c());
-        second_loader_new.set_b_to_boolean(second_loader.b_is_constant());
-        second_loader_new.set_c_to_boolean(second_loader.c_is_constant());
-
-        *second_loader = second_loader_new;
-    }
-
-    fn operations_iter(&self) -> OperationIter {
-        self.instructions
-            .iter()
-            .map(|(instruction, _)| instruction.operation())
-    }
-
-    fn get_operations<const COUNT: usize>(&self) -> Option<[Operation; COUNT]> {
-        if self.instructions.len() < COUNT {
-            return None;
-        }
-
-        let mut n_operations = [Operation::Return; COUNT];
-
-        for (nth, operation) in n_operations.iter_mut().zip(self.operations_iter()) {
-            *nth = operation;
-        }
-
-        Some(n_operations)
-    }
-}

dust-lang/src/token.rs

@@ -1,642 +0,0 @@
-//! Token, TokenOwned and TokenKind types.
-use std::fmt::{self, Display, Formatter};
-
-use serde::{Deserialize, Serialize};
-
-macro_rules! define_tokens {
-    ($($variant:ident $(($data_type:ty))?),+ $(,)?) => {
-        /// Source token.
-        ///
-        /// This is a borrowed type, i.e. some variants contain references to the source text.
-        #[derive(Debug, Clone, Copy, Eq, PartialEq, PartialOrd, Ord, Default, Serialize, Deserialize)]
-        pub enum Token<'src> {
-            #[default]
-            Eof,
-            $(
-                $variant $(($data_type))?,
-            )*
-        }
-
-        #[derive(Debug, PartialEq, Clone)]
-        /// Data-less representation of a source token.
-        ///
-        /// If a [Token] borrows from the source text, its TokenKind omits the data.
-        pub enum TokenKind {
-            Eof,
-            $(
-                $variant,
-            )*
-        }
-    };
-}
-
-define_tokens! {
-    // Hard-coded values
-    Boolean(&'src str),
-    Byte(&'src str),
-    Character(char),
-    Float(&'src str),
-    Identifier(&'src str),
-    Integer(&'src str),
-    String(&'src str),
-
-    // Keywords
-    Async,
-    Bool,
-    Break,
-    Else,
-    FloatKeyword,
-    Fn,
-    If,
-    Int,
-    Let,
-    Loop,
-    Map,
-    Mut,
-    Return,
-    Str,
-    Struct,
-    While,
-
-    // Symbols
-    ArrowThin,
-    BangEqual,
-    Bang,
-    Colon,
-    Comma,
-    Dot,
-    DoubleAmpersand,
-    DoubleDot,
-    DoubleEqual,
-    DoublePipe,
-    Equal,
-    Greater,
-    GreaterEqual,
-    LeftCurlyBrace,
-    LeftParenthesis,
-    LeftSquareBrace,
-    Less,
-    LessEqual,
-    Minus,
-    MinusEqual,
-    Percent,
-    PercentEqual,
-    Plus,
-    PlusEqual,
-    RightCurlyBrace,
-    RightParenthesis,
-    RightSquareBrace,
-    Semicolon,
-    Slash,
-    SlashEqual,
-    Star,
-    StarEqual,
-}
-
-impl<'src> Token<'src> {
-    #[allow(clippy::len_without_is_empty)]
-    pub fn len(&self) -> usize {
-        match self {
-            Token::Eof => 0,
-            Token::Boolean(text) => text.len(),
-            Token::Byte(_) => 3,
-            Token::Character(_) => 3,
-            Token::Float(text) => text.len(),
-            Token::Identifier(text) => text.len(),
-            Token::Integer(text) => text.len(),
-            Token::String(text) => text.len() + 2,
-            Token::Async => 5,
-            Token::ArrowThin => 2,
-            Token::Bool => 4,
-            Token::Break => 5,
-            Token::Else => 4,
-            Token::FloatKeyword => 5,
-            Token::Fn => 2,
-            Token::If => 2,
-            Token::Int => 3,
-            Token::Let => 3,
-            Token::Loop => 4,
-            Token::Map => 3,
-            Token::Mut => 3,
-            Token::Str => 3,
-            Token::Struct => 6,
-            Token::While => 5,
-            Token::BangEqual => 2,
-            Token::Bang => 1,
-            Token::Colon => 1,
-            Token::Comma => 1,
-            Token::Dot => 1,
-            Token::DoubleAmpersand => 2,
-            Token::DoubleDot => 2,
-            Token::DoubleEqual => 2,
-            Token::DoublePipe => 2,
-            Token::Equal => 1,
-            Token::Greater => 1,
-            Token::GreaterEqual => 2,
-            Token::LeftCurlyBrace => 1,
-            Token::LeftParenthesis => 1,
-            Token::LeftSquareBrace => 1,
-            Token::Less => 1,
-            Token::LessEqual => 2,
-            Token::Minus => 1,
-            Token::MinusEqual => 2,
-            Token::Percent => 1,
-            Token::PercentEqual => 2,
-            Token::Plus => 1,
-            Token::PlusEqual => 2,
-            Token::Return => 6,
-            Token::RightCurlyBrace => 1,
-            Token::RightParenthesis => 1,
-            Token::RightSquareBrace => 1,
-            Token::Semicolon => 1,
-            Token::Slash => 1,
-            Token::SlashEqual => 2,
-            Token::Star => 1,
-            Token::StarEqual => 2,
-        }
-    }
-
-    pub fn as_str(&self) -> &str {
-        match self {
-            Token::Eof => "",
-            Token::Boolean(text) => text,
-            Token::Byte(text) => text,
-            Token::Character(_) => "character token",
-            Token::Float(text) => text,
-            Token::Identifier(text) => text,
-            Token::Integer(text) => text,
-            Token::String(text) => text,
-            Token::Async => "async",
-            Token::ArrowThin => "->",
-            Token::Bool => "bool",
-            Token::Break => "break",
-            Token::Else => "else",
-            Token::FloatKeyword => "float",
-            Token::Fn => "fn",
-            Token::If => "if",
-            Token::Int => "int",
-            Token::Let => "let",
-            Token::Loop => "loop",
-            Token::Map => "map",
-            Token::Mut => "mut",
-            Token::Str => "str",
-            Token::Struct => "struct",
-            Token::While => "while",
-            Token::BangEqual => "!=",
-            Token::Bang => "!",
-            Token::Colon => ":",
-            Token::Comma => ",",
-            Token::Dot => ".",
-            Token::DoubleAmpersand => "&&",
-            Token::DoubleDot => "..",
-            Token::DoubleEqual => "==",
-            Token::DoublePipe => "||",
-            Token::Equal => "=",
-            Token::Greater => ">",
-            Token::GreaterEqual => ">=",
-            Token::LeftCurlyBrace => "{",
-            Token::LeftParenthesis => "(",
-            Token::LeftSquareBrace => "[",
-            Token::Less => "<",
-            Token::LessEqual => "<=",
-            Token::Minus => "-",
-            Token::MinusEqual => "-=",
-            Token::Percent => "%",
-            Token::PercentEqual => "%=",
-            Token::Plus => "+",
-            Token::PlusEqual => "+=",
-            Token::Return => "return",
-            Token::RightCurlyBrace => "}",
-            Token::RightParenthesis => ")",
-            Token::RightSquareBrace => "]",
-            Token::Semicolon => ";",
-            Token::Slash => "/",
-            Token::SlashEqual => "/=",
-            Token::Star => "*",
-            Token::StarEqual => "*=",
-        }
-    }
-
-    pub fn to_owned(&self) -> TokenOwned {
-        match self {
-            Token::ArrowThin => TokenOwned::ArrowThin,
-            Token::Async => TokenOwned::Async,
-            Token::BangEqual => TokenOwned::BangEqual,
-            Token::Bang => TokenOwned::Bang,
-            Token::Bool => TokenOwned::Bool,
-            Token::Boolean(boolean) => TokenOwned::Boolean(boolean.to_string()),
-            Token::Break => TokenOwned::Break,
-            Token::Byte(byte) => TokenOwned::Byte(byte.to_string()),
-            Token::Character(character) => TokenOwned::Character(*character),
-            Token::Colon => TokenOwned::Colon,
-            Token::Comma => TokenOwned::Comma,
-            Token::Dot => TokenOwned::Dot,
-            Token::DoubleAmpersand => TokenOwned::DoubleAmpersand,
-            Token::DoubleDot => TokenOwned::DoubleDot,
-            Token::DoubleEqual => TokenOwned::DoubleEqual,
-            Token::DoublePipe => TokenOwned::DoublePipe,
-            Token::Else => TokenOwned::Else,
-            Token::Eof => TokenOwned::Eof,
-            Token::Equal => TokenOwned::Equal,
-            Token::Float(float) => TokenOwned::Float(float.to_string()),
-            Token::FloatKeyword => TokenOwned::FloatKeyword,
-            Token::Fn => TokenOwned::Fn,
-            Token::Greater => TokenOwned::Greater,
-            Token::GreaterEqual => TokenOwned::GreaterOrEqual,
-            Token::Identifier(text) => TokenOwned::Identifier(text.to_string()),
-            Token::If => TokenOwned::If,
-            Token::Int => TokenOwned::Int,
-            Token::Integer(integer) => TokenOwned::Integer(integer.to_string()),
-            Token::LeftCurlyBrace => TokenOwned::LeftCurlyBrace,
-            Token::LeftParenthesis => TokenOwned::LeftParenthesis,
-            Token::LeftSquareBrace => TokenOwned::LeftSquareBrace,
-            Token::Let => TokenOwned::Let,
-            Token::Less => TokenOwned::Less,
-            Token::LessEqual => TokenOwned::LessOrEqual,
-            Token::Loop => TokenOwned::Loop,
-            Token::Map => TokenOwned::Map,
-            Token::Minus => TokenOwned::Minus,
-            Token::MinusEqual => TokenOwned::MinusEqual,
-            Token::Mut => TokenOwned::Mut,
-            Token::Percent => TokenOwned::Percent,
-            Token::PercentEqual => TokenOwned::PercentEqual,
-            Token::Plus => TokenOwned::Plus,
-            Token::PlusEqual => TokenOwned::PlusEqual,
-            Token::Return => TokenOwned::Return,
-            Token::RightCurlyBrace => TokenOwned::RightCurlyBrace,
-            Token::RightParenthesis => TokenOwned::RightParenthesis,
-            Token::RightSquareBrace => TokenOwned::RightSquareBrace,
-            Token::Semicolon => TokenOwned::Semicolon,
-            Token::Star => TokenOwned::Star,
-            Token::StarEqual => TokenOwned::StarEqual,
-            Token::Slash => TokenOwned::Slash,
-            Token::SlashEqual => TokenOwned::SlashEqual,
-            Token::String(text) => TokenOwned::String(text.to_string()),
-            Token::Str => TokenOwned::Str,
-            Token::Struct => TokenOwned::Struct,
-            Token::While => TokenOwned::While,
-        }
-    }
-
-    pub fn kind(&self) -> TokenKind {
-        match self {
-            Token::ArrowThin => TokenKind::ArrowThin,
-            Token::Async => TokenKind::Async,
-            Token::BangEqual => TokenKind::BangEqual,
-            Token::Bang => TokenKind::Bang,
-            Token::Bool => TokenKind::Bool,
-            Token::Boolean(_) => TokenKind::Boolean,
-            Token::Break => TokenKind::Break,
-            Token::Byte(_) => TokenKind::Byte,
-            Token::Character(_) => TokenKind::Character,
-            Token::Colon => TokenKind::Colon,
-            Token::Comma => TokenKind::Comma,
-            Token::Dot => TokenKind::Dot,
-            Token::DoubleAmpersand => TokenKind::DoubleAmpersand,
-            Token::DoubleDot => TokenKind::DoubleDot,
-            Token::DoubleEqual => TokenKind::DoubleEqual,
-            Token::DoublePipe => TokenKind::DoublePipe,
-            Token::Else => TokenKind::Else,
-            Token::Eof => TokenKind::Eof,
-            Token::Equal => TokenKind::Equal,
-            Token::Float(_) => TokenKind::Float,
-            Token::FloatKeyword => TokenKind::FloatKeyword,
-            Token::Fn => TokenKind::Fn,
-            Token::Greater => TokenKind::Greater,
-            Token::GreaterEqual => TokenKind::GreaterEqual,
-            Token::Identifier(_) => TokenKind::Identifier,
-            Token::If => TokenKind::If,
-            Token::Int => TokenKind::Int,
-            Token::Integer(_) => TokenKind::Integer,
-            Token::LeftCurlyBrace => TokenKind::LeftCurlyBrace,
-            Token::LeftParenthesis => TokenKind::LeftParenthesis,
-            Token::LeftSquareBrace => TokenKind::LeftSquareBrace,
-            Token::Let => TokenKind::Let,
-            Token::Less => TokenKind::Less,
-            Token::LessEqual => TokenKind::LessEqual,
-            Token::Loop => TokenKind::Loop,
-            Token::Map => TokenKind::Map,
-            Token::Minus => TokenKind::Minus,
-            Token::MinusEqual => TokenKind::MinusEqual,
-            Token::Mut => TokenKind::Mut,
-            Token::Percent => TokenKind::Percent,
-            Token::PercentEqual => TokenKind::PercentEqual,
-            Token::Plus => TokenKind::Plus,
-            Token::PlusEqual => TokenKind::PlusEqual,
-            Token::Return => TokenKind::Return,
-            Token::RightCurlyBrace => TokenKind::RightCurlyBrace,
-            Token::RightParenthesis => TokenKind::RightParenthesis,
-            Token::RightSquareBrace => TokenKind::RightSquareBrace,
-            Token::Semicolon => TokenKind::Semicolon,
-            Token::Star => TokenKind::Star,
-            Token::StarEqual => TokenKind::StarEqual,
-            Token::Slash => TokenKind::Slash,
-            Token::SlashEqual => TokenKind::SlashEqual,
-            Token::Str => TokenKind::Str,
-            Token::String(_) => TokenKind::String,
-            Token::Struct => TokenKind::Struct,
-            Token::While => TokenKind::While,
-        }
-    }
-
-    /// Returns true if the token yields a value, begins an expression or is an expression operator.
-    pub fn is_expression(&self) -> bool {
-        matches!(
-            self,
-            Token::Boolean(_)
-                | Token::Byte(_)
-                | Token::Character(_)
-                | Token::Float(_)
-                | Token::Identifier(_)
-                | Token::Integer(_)
-                | Token::String(_)
-                | Token::Break
-                | Token::If
-                | Token::Return
-                | Token::Map
-                | Token::Loop
-                | Token::Struct
-                | Token::BangEqual
-                | Token::DoubleAmpersand
-                | Token::DoubleEqual
-                | Token::DoublePipe
-                | Token::Equal
-                | Token::Greater
-                | Token::GreaterEqual
-                | Token::LeftCurlyBrace
-                | Token::LeftParenthesis
-                | Token::LeftSquareBrace
-                | Token::Less
-                | Token::LessEqual
-                | Token::Minus
-                | Token::MinusEqual
-                | Token::Percent
-                | Token::PercentEqual
-                | Token::Plus
-                | Token::PlusEqual
-                | Token::Slash
-                | Token::SlashEqual
-                | Token::Star
-                | Token::StarEqual
-        )
-    }
-}
-
-impl<'src> Display for Token<'src> {
-    fn fmt(&self, f: &mut Formatter) -> fmt::Result {
-        match self {
-            Token::ArrowThin => write!(f, "->"),
-            Token::Async => write!(f, "async"),
-            Token::BangEqual => write!(f, "!="),
-            Token::Bang => write!(f, "!"),
-            Token::Bool => write!(f, "bool"),
-            Token::Boolean(value) => write!(f, "{value}"),
-            Token::Break => write!(f, "break"),
-            Token::Byte(value) => write!(f, "{value}"),
-            Token::Character(value) => write!(f, "{value}"),
-            Token::Colon => write!(f, ":"),
-            Token::Comma => write!(f, ","),
-            Token::Dot => write!(f, "."),
-            Token::DoubleAmpersand => write!(f, "&&"),
-            Token::DoubleDot => write!(f, ".."),
-            Token::DoubleEqual => write!(f, "=="),
-            Token::DoublePipe => write!(f, "||"),
-            Token::Else => write!(f, "else"),
-            Token::Eof => write!(f, "EOF"),
-            Token::Equal => write!(f, "="),
-            Token::Float(value) => write!(f, "{value}"),
-            Token::FloatKeyword => write!(f, "float"),
-            Token::Fn => write!(f, "fn"),
-            Token::Greater => write!(f, ">"),
-            Token::GreaterEqual => write!(f, ">="),
-            Token::Identifier(value) => write!(f, "{value}"),
-            Token::If => write!(f, "if"),
-            Token::Int => write!(f, "int"),
-            Token::Integer(value) => write!(f, "{value}"),
-            Token::LeftCurlyBrace => write!(f, "{{"),
-            Token::LeftParenthesis => write!(f, "("),
-            Token::LeftSquareBrace => write!(f, "["),
-            Token::Let => write!(f, "let"),
-            Token::Less => write!(f, "<"),
-            Token::LessEqual => write!(f, "<="),
-            Token::Loop => write!(f, "loop"),
-            Token::Map => write!(f, "map"),
-            Token::Minus => write!(f, "-"),
-            Token::MinusEqual => write!(f, "-="),
-            Token::Mut => write!(f, "mut"),
-            Token::Percent => write!(f, "%"),
-            Token::PercentEqual => write!(f, "%="),
-            Token::Plus => write!(f, "+"),
-            Token::PlusEqual => write!(f, "+="),
-            Token::Return => write!(f, "return"),
-            Token::RightCurlyBrace => write!(f, "}}"),
-            Token::RightParenthesis => write!(f, ")"),
-            Token::RightSquareBrace => write!(f, "]"),
-            Token::Semicolon => write!(f, ";"),
-            Token::Slash => write!(f, "/"),
-            Token::SlashEqual => write!(f, "/="),
-            Token::Star => write!(f, "*"),
-            Token::StarEqual => write!(f, "*="),
-            Token::Str => write!(f, "str"),
-            Token::String(value) => write!(f, "{value}"),
-            Token::Struct => write!(f, "struct"),
-            Token::While => write!(f, "while"),
-        }
-    }
-}
-
-/// Owned representation of a source token.
-///
-/// If a [Token] borrows from the source text, its TokenOwned omits the data.
-#[derive(Debug, PartialEq, Clone)]
-pub enum TokenOwned {
-    Eof,
-
-    Identifier(String),
-
-    // Hard-coded values
-    Boolean(String),
-    Byte(String),
-    Character(char),
-    Float(String),
-    Integer(String),
-    String(String),
-
-    // Keywords
-    Async,
-    Bool,
-    Break,
-    Else,
-    FloatKeyword,
-    Fn,
-    If,
-    Int,
-    Let,
-    Loop,
-    Map,
-    Mut,
-    Return,
-    Str,
-    While,
-
-    // Symbols
-    ArrowThin,
-    Bang,
-    BangEqual,
-    Colon,
-    Comma,
-    Dot,
-    DoubleAmpersand,
-    DoubleDot,
-    DoubleEqual,
-    DoublePipe,
-    Equal,
-    Greater,
-    GreaterOrEqual,
-    LeftCurlyBrace,
-    LeftParenthesis,
-    LeftSquareBrace,
-    Less,
-    LessOrEqual,
-    Minus,
-    MinusEqual,
-    Percent,
-    PercentEqual,
-    Plus,
-    PlusEqual,
-    RightCurlyBrace,
-    RightParenthesis,
-    RightSquareBrace,
-    Semicolon,
-    Star,
-    StarEqual,
-    Struct,
-    Slash,
-    SlashEqual,
-}
-
-impl Display for TokenOwned {
-    fn fmt(&self, f: &mut Formatter<'_>) -> fmt::Result {
-        match self {
-            TokenOwned::ArrowThin => Token::ArrowThin.fmt(f),
-            TokenOwned::Async => Token::Async.fmt(f),
-            TokenOwned::Bang => Token::Bang.fmt(f),
-            TokenOwned::BangEqual => Token::BangEqual.fmt(f),
-            TokenOwned::Bool => Token::Bool.fmt(f),
-            TokenOwned::Boolean(boolean) => Token::Boolean(boolean).fmt(f),
-            TokenOwned::Break => Token::Break.fmt(f),
-            TokenOwned::Byte(byte) => Token::Byte(byte).fmt(f),
-            TokenOwned::Character(character) => Token::Character(*character).fmt(f),
-            TokenOwned::Colon => Token::Colon.fmt(f),
-            TokenOwned::Comma => Token::Comma.fmt(f),
-            TokenOwned::Dot => Token::Dot.fmt(f),
-            TokenOwned::DoubleAmpersand => Token::DoubleAmpersand.fmt(f),
-            TokenOwned::DoubleDot => Token::DoubleDot.fmt(f),
-            TokenOwned::DoubleEqual => Token::DoubleEqual.fmt(f),
-            TokenOwned::DoublePipe => Token::DoublePipe.fmt(f),
-            TokenOwned::Else => Token::Else.fmt(f),
-            TokenOwned::Eof => Token::Eof.fmt(f),
-            TokenOwned::Equal => Token::Equal.fmt(f),
-            TokenOwned::Float(float) => Token::Float(float).fmt(f),
-            TokenOwned::FloatKeyword => Token::FloatKeyword.fmt(f),
-            TokenOwned::Fn => Token::Fn.fmt(f),
-            TokenOwned::Greater => Token::Greater.fmt(f),
-            TokenOwned::GreaterOrEqual => Token::GreaterEqual.fmt(f),
-            TokenOwned::Identifier(text) => Token::Identifier(text).fmt(f),
-            TokenOwned::If => Token::If.fmt(f),
-            TokenOwned::Int => Token::Int.fmt(f),
-            TokenOwned::Integer(integer) => Token::Integer(integer).fmt(f),
-            TokenOwned::LeftCurlyBrace => Token::LeftCurlyBrace.fmt(f),
-            TokenOwned::LeftParenthesis => Token::LeftParenthesis.fmt(f),
-            TokenOwned::LeftSquareBrace => Token::LeftSquareBrace.fmt(f),
-            TokenOwned::Let => Token::Let.fmt(f),
-            TokenOwned::Less => Token::Less.fmt(f),
-            TokenOwned::LessOrEqual => Token::LessEqual.fmt(f),
-            TokenOwned::Loop => Token::Loop.fmt(f),
-            TokenOwned::Map => Token::Map.fmt(f),
-            TokenOwned::Minus => Token::Minus.fmt(f),
-            TokenOwned::MinusEqual => Token::MinusEqual.fmt(f),
-            TokenOwned::Mut => Token::Mut.fmt(f),
-            TokenOwned::Percent => Token::Percent.fmt(f),
-            TokenOwned::PercentEqual => Token::PercentEqual.fmt(f),
-            TokenOwned::Plus => Token::Plus.fmt(f),
-            TokenOwned::PlusEqual => Token::PlusEqual.fmt(f),
-            TokenOwned::Return => Token::Return.fmt(f),
-            TokenOwned::RightCurlyBrace => Token::RightCurlyBrace.fmt(f),
-            TokenOwned::RightParenthesis => Token::RightParenthesis.fmt(f),
-            TokenOwned::RightSquareBrace => Token::RightSquareBrace.fmt(f),
-            TokenOwned::Semicolon => Token::Semicolon.fmt(f),
-            TokenOwned::Star => Token::Star.fmt(f),
-            TokenOwned::StarEqual => Token::StarEqual.fmt(f),
-            TokenOwned::Slash => Token::Slash.fmt(f),
-            TokenOwned::SlashEqual => Token::SlashEqual.fmt(f),
-            TokenOwned::Str => Token::Str.fmt(f),
-            TokenOwned::String(string) => Token::String(string).fmt(f),
-            TokenOwned::Struct => Token::Struct.fmt(f),
-            TokenOwned::While => Token::While.fmt(f),
-        }
-    }
-}
-
-impl Display for TokenKind {
-    fn fmt(&self, f: &mut Formatter<'_>) -> fmt::Result {
-        match self {
-            TokenKind::ArrowThin => Token::ArrowThin.fmt(f),
-            TokenKind::Async => Token::Async.fmt(f),
-            TokenKind::Bang => Token::Bang.fmt(f),
-            TokenKind::BangEqual => Token::BangEqual.fmt(f),
-            TokenKind::Bool => Token::Bool.fmt(f),
-            TokenKind::Boolean => write!(f, "boolean value"),
-            TokenKind::Break => Token::Break.fmt(f),
-            TokenKind::Byte => write!(f, "byte value"),
-            TokenKind::Character => write!(f, "character value"),
-            TokenKind::Colon => Token::Colon.fmt(f),
-            TokenKind::Comma => Token::Comma.fmt(f),
-            TokenKind::Dot => Token::Dot.fmt(f),
-            TokenKind::DoubleAmpersand => Token::DoubleAmpersand.fmt(f),
-            TokenKind::DoubleDot => Token::DoubleDot.fmt(f),
-            TokenKind::DoubleEqual => Token::DoubleEqual.fmt(f),
-            TokenKind::DoublePipe => Token::DoublePipe.fmt(f),
-            TokenKind::Else => Token::Else.fmt(f),
-            TokenKind::Eof => Token::Eof.fmt(f),
-            TokenKind::Equal => Token::Equal.fmt(f),
-            TokenKind::Float => write!(f, "float value"),
-            TokenKind::FloatKeyword => Token::FloatKeyword.fmt(f),
-            TokenKind::Fn => Token::Fn.fmt(f),
-            TokenKind::Greater => Token::Greater.fmt(f),
-            TokenKind::GreaterEqual => Token::GreaterEqual.fmt(f),
-            TokenKind::Identifier => write!(f, "identifier"),
-            TokenKind::If => Token::If.fmt(f),
-            TokenKind::Int => Token::Int.fmt(f),
-            TokenKind::Integer => write!(f, "integer value"),
-            TokenKind::LeftCurlyBrace => Token::LeftCurlyBrace.fmt(f),
-            TokenKind::LeftParenthesis => Token::LeftParenthesis.fmt(f),
-            TokenKind::LeftSquareBrace => Token::LeftSquareBrace.fmt(f),
-            TokenKind::Let => Token::Let.fmt(f),
-            TokenKind::Less => Token::Less.fmt(f),
-            TokenKind::LessEqual => Token::LessEqual.fmt(f),
-            TokenKind::Loop => Token::Loop.fmt(f),
-            TokenKind::Map => Token::Map.fmt(f),
-            TokenKind::Minus => Token::Minus.fmt(f),
-            TokenKind::MinusEqual => Token::MinusEqual.fmt(f),
-            TokenKind::Mut => Token::Mut.fmt(f),
-            TokenKind::Percent => Token::Percent.fmt(f),
-            TokenKind::PercentEqual => Token::PercentEqual.fmt(f),
-            TokenKind::Plus => Token::Plus.fmt(f),
-            TokenKind::PlusEqual => Token::PlusEqual.fmt(f),
-            TokenKind::Return => Token::Return.fmt(f),
-            TokenKind::RightCurlyBrace => Token::RightCurlyBrace.fmt(f),
-            TokenKind::RightParenthesis => Token::RightParenthesis.fmt(f),
-            TokenKind::RightSquareBrace => Token::RightSquareBrace.fmt(f),
-            TokenKind::Semicolon => Token::Semicolon.fmt(f),
-            TokenKind::Star => Token::Star.fmt(f),
-            TokenKind::StarEqual => Token::StarEqual.fmt(f),
-            TokenKind::Str => Token::Str.fmt(f),
-            TokenKind::Slash => Token::Slash.fmt(f),
-            TokenKind::SlashEqual => Token::SlashEqual.fmt(f),
-            TokenKind::String => write!(f, "string value"),
-            TokenKind::Struct => Token::Struct.fmt(f),
-            TokenKind::While => Token::While.fmt(f),
-        }
-    }
-}

dust-lang/src/type.rs

@@ -1,659 +0,0 @@
-//! Value types and conflict handling.
-use std::{
-    cmp::Ordering,
-    collections::HashMap,
-    fmt::{self, Display, Formatter},
-};
-
-use serde::{Deserialize, Serialize};
-
-/// Description of a kind of value.
-#[derive(Clone, Debug, Eq, PartialEq, Serialize, Deserialize)]
-pub enum Type {
-    Any,
-    Boolean,
-    Byte,
-    Character,
-    Enum(EnumType),
-    Float,
-    Function(FunctionType),
-    Generic {
-        identifier_index: u8,
-        concrete_type: Option<Box<Type>>,
-    },
-    Integer,
-    List {
-        item_type: Box<Type>,
-        length: usize,
-    },
-    ListEmpty,
-    ListOf {
-        item_type: Box<Type>,
-    },
-    Map {
-        pairs: HashMap<u8, Type>,
-    },
-    Number,
-    Range {
-        r#type: RangeableType,
-    },
-    String {
-        length: Option<usize>,
-    },
-    Struct(StructType),
-    Tuple {
-        fields: Option<Vec<Type>>,
-    },
-}
-
-impl Type {
-    /// Returns a concrete type, either the type itself or the concrete type of a generic type.
-    pub fn concrete_type(&self) -> &Type {
-        if let Type::Generic {
-            concrete_type: Some(concrete_type),
-            ..
-        } = self
-        {
-            concrete_type.concrete_type()
-        } else {
-            self
-        }
-    }
-
-    /// Checks that the type is compatible with another type.
-    pub fn check(&self, other: &Type) -> Result<(), TypeConflict> {
-        match (self.concrete_type(), other.concrete_type()) {
-            (Type::Any, _)
-            | (_, Type::Any)
-            | (Type::Boolean, Type::Boolean)
-            | (Type::Byte, Type::Byte)
-            | (Type::Character, Type::Character)
-            | (Type::Float, Type::Float)
-            | (Type::Integer, Type::Integer)
-            | (Type::String { .. }, Type::String { .. }) => return Ok(()),
-            (
-                Type::Generic {
-                    concrete_type: left,
-                    ..
-                },
-                Type::Generic {
-                    concrete_type: right,
-                    ..
-                },
-            ) => match (left, right) {
-                (Some(left), Some(right)) => {
-                    if left.check(right).is_ok() {
-                        return Ok(());
-                    }
-                }
-                (None, None) => {
-                    return Ok(());
-                }
-                _ => {}
-            },
-            (Type::Generic { concrete_type, .. }, other)
-            | (other, Type::Generic { concrete_type, .. }) => {
-                if let Some(concrete_type) = concrete_type {
-                    if other == concrete_type.as_ref() {
-                        return Ok(());
-                    }
-                }
-            }
-            (Type::Struct(left_struct_type), Type::Struct(right_struct_type)) => {
-                if left_struct_type == right_struct_type {
-                    return Ok(());
-                }
-            }
-            (
-                Type::List {
-                    item_type: left_type,
-                    length: left_length,
-                },
-                Type::List {
-                    item_type: right_type,
-                    length: right_length,
-                },
-            ) => {
-                if left_length != right_length {
-                    return Err(TypeConflict {
-                        actual: other.clone(),
-                        expected: self.clone(),
-                    });
-                }
-
-                if left_type.check(right_type).is_err() {
-                    return Err(TypeConflict {
-                        actual: other.clone(),
-                        expected: self.clone(),
-                    });
-                }
-
-                return Ok(());
-            }
-            (
-                Type::ListOf {
-                    item_type: left_type,
-                },
-                Type::ListOf {
-                    item_type: right_type,
-                },
-            ) => {
-                if left_type.check(right_type).is_err() {
-                    return Err(TypeConflict {
-                        actual: other.clone(),
-                        expected: self.clone(),
-                    });
-                }
-            }
-            (
-                Type::List {
-                    item_type: list_item_type,
-                    ..
-                },
-                Type::ListOf {
-                    item_type: list_of_item_type,
-                },
-            )
-            | (
-                Type::ListOf {
-                    item_type: list_of_item_type,
-                },
-                Type::List {
-                    item_type: list_item_type,
-                    ..
-                },
-            ) => {
-                // TODO: This is a hack, remove it.
-                if let Type::Any = **list_of_item_type {
-                    return Ok(());
-                }
-
-                if list_item_type.check(list_of_item_type).is_err() {
-                    return Err(TypeConflict {
-                        actual: other.clone(),
-                        expected: self.clone(),
-                    });
-                }
-            }
-            (
-                Type::Function(FunctionType {
-                    type_parameters: left_type_parameters,
-                    value_parameters: left_value_parameters,
-                    return_type: left_return,
-                }),
-                Type::Function(FunctionType {
-                    type_parameters: right_type_parameters,
-                    value_parameters: right_value_parameters,
-                    return_type: right_return,
-                }),
-            ) => {
-                if left_return != right_return
-                    || left_type_parameters != right_type_parameters
-                    || left_value_parameters != right_value_parameters
-                {
-                    return Err(TypeConflict {
-                        actual: other.clone(),
-                        expected: self.clone(),
-                    });
-                }
-
-                return Ok(());
-            }
-            (Type::Range { r#type: left_type }, Type::Range { r#type: right_type }) => {
-                if left_type == right_type {
-                    return Ok(());
-                }
-            }
-            (Type::Number, Type::Number | Type::Integer | Type::Float)
-            | (Type::Integer | Type::Float, Type::Number) => {
-                return Ok(());
-            }
-            _ => {}
-        }
-
-        Err(TypeConflict {
-            actual: other.clone(),
-            expected: self.clone(),
-        })
-    }
-}
-
-impl Display for Type {
-    fn fmt(&self, f: &mut Formatter) -> fmt::Result {
-        match self {
-            Type::Any => write!(f, "any"),
-            Type::Boolean => write!(f, "bool"),
-            Type::Byte => write!(f, "byte"),
-            Type::Character => write!(f, "char"),
-            Type::Enum(EnumType { name, .. }) => write!(f, "{name}"),
-            Type::Float => write!(f, "float"),
-            Type::Function(function_type) => write!(f, "{function_type}"),
-            Type::Generic { concrete_type, .. } => {
-                match concrete_type.clone().map(|r#box| *r#box) {
-                    Some(Type::Generic {
-                        identifier_index: identifier,
-                        ..
-                    }) => write!(f, "{identifier}"),
-                    Some(concrete_type) => write!(f, "implied to be {concrete_type}"),
-                    None => write!(f, "unknown"),
-                }
-            }
-            Type::Integer => write!(f, "int"),
-            Type::List { item_type, length } => write!(f, "[{item_type}; {length}]"),
-            Type::ListEmpty => write!(f, "[]"),
-            Type::ListOf { item_type } => write!(f, "[{item_type}]"),
-            Type::Map { pairs } => {
-                write!(f, "map ")?;
-
-                write!(f, "{{")?;
-
-                for (index, (key, value)) in pairs.iter().enumerate() {
-                    write!(f, "{key}: {value}")?;
-
-                    if index != pairs.len() - 1 {
-                        write!(f, ", ")?;
-                    }
-                }
-
-                write!(f, "}}")
-            }
-            Type::Number => write!(f, "num"),
-            Type::Range { r#type } => write!(f, "{type} range"),
-            Type::String { .. } => write!(f, "str"),
-            Type::Struct(struct_type) => write!(f, "{struct_type}"),
-            Type::Tuple { fields } => {
-                if let Some(fields) = fields {
-                    write!(f, "(")?;
-
-                    for (index, r#type) in fields.iter().enumerate() {
-                        write!(f, "{type}")?;
-
-                        if index != fields.len() - 1 {
-                            write!(f, ", ")?;
-                        }
-                    }
-
-                    write!(f, ")")
-                } else {
-                    write!(f, "tuple")
-                }
-            }
-        }
-    }
-}
-
-impl PartialOrd for Type {
-    fn partial_cmp(&self, other: &Self) -> Option<Ordering> {
-        Some(self.cmp(other))
-    }
-}
-
-impl Ord for Type {
-    fn cmp(&self, other: &Self) -> Ordering {
-        match (self, other) {
-            (Type::Any, Type::Any) => Ordering::Equal,
-            (Type::Any, _) => Ordering::Greater,
-            (Type::Boolean, Type::Boolean) => Ordering::Equal,
-            (Type::Boolean, _) => Ordering::Greater,
-            (Type::Byte, Type::Byte) => Ordering::Equal,
-            (Type::Byte, _) => Ordering::Greater,
-            (Type::Character, Type::Character) => Ordering::Equal,
-            (Type::Character, _) => Ordering::Greater,
-            (Type::Enum(left_enum), Type::Enum(right_enum)) => left_enum.cmp(right_enum),
-            (Type::Enum(_), _) => Ordering::Greater,
-            (Type::Float, Type::Float) => Ordering::Equal,
-            (Type::Float, _) => Ordering::Greater,
-            (Type::Function(left_function), Type::Function(right_function)) => {
-                left_function.cmp(right_function)
-            }
-            (Type::Function(_), _) => Ordering::Greater,
-            (Type::Generic { .. }, Type::Generic { .. }) => Ordering::Equal,
-            (Type::Generic { .. }, _) => Ordering::Greater,
-            (Type::Integer, Type::Integer) => Ordering::Equal,
-            (Type::Integer, _) => Ordering::Greater,
-            (
-                Type::List {
-                    item_type: left_item_type,
-                    length: left_length,
-                },
-                Type::List {
-                    item_type: right_item_type,
-                    length: right_length,
-                },
-            ) => {
-                if left_length == right_length {
-                    left_item_type.cmp(right_item_type)
-                } else {
-                    left_length.cmp(right_length)
-                }
-            }
-            (Type::List { .. }, _) => Ordering::Greater,
-            (Type::ListEmpty, Type::ListEmpty) => Ordering::Equal,
-            (Type::ListEmpty, _) => Ordering::Greater,
-            (
-                Type::ListOf {
-                    item_type: left_item_type,
-                },
-                Type::ListOf {
-                    item_type: right_item_type,
-                },
-            ) => left_item_type.cmp(right_item_type),
-            (Type::ListOf { .. }, _) => Ordering::Greater,
-            (Type::Map { pairs: left_pairs }, Type::Map { pairs: right_pairs }) => {
-                left_pairs.iter().cmp(right_pairs.iter())
-            }
-            (Type::Map { .. }, _) => Ordering::Greater,
-            (Type::Number, Type::Number) => Ordering::Equal,
-            (Type::Number, _) => Ordering::Greater,
-            (Type::Range { r#type: left_type }, Type::Range { r#type: right_type }) => {
-                left_type.cmp(right_type)
-            }
-            (Type::Range { .. }, _) => Ordering::Greater,
-            (Type::String { length: left }, Type::String { length: right }) => left.cmp(right),
-            (Type::String { .. }, _) => Ordering::Greater,
-            (Type::Struct(left_struct), Type::Struct(right_struct)) => {
-                left_struct.cmp(right_struct)
-            }
-            (Type::Struct(_), _) => Ordering::Greater,
-
-            (Type::Tuple { fields: left }, Type::Tuple { fields: right }) => left.cmp(right),
-            (Type::Tuple { .. }, _) => Ordering::Greater,
-        }
-    }
-}
-
-#[derive(Clone, Debug, Eq, PartialEq, PartialOrd, Ord, Serialize, Deserialize)]
-pub struct FunctionType {
-    pub type_parameters: Option<Vec<u8>>,
-    pub value_parameters: Option<Vec<(u8, Type)>>,
-    pub return_type: Option<Box<Type>>,
-}
-
-impl Display for FunctionType {
-    fn fmt(&self, f: &mut Formatter<'_>) -> fmt::Result {
-        write!(f, "fn ")?;
-
-        if let Some(type_parameters) = &self.type_parameters {
-            write!(f, "<")?;
-
-            for (index, type_parameter) in type_parameters.iter().enumerate() {
-                if index > 0 {
-                    write!(f, ", ")?;
-                }
-
-                write!(f, "{type_parameter}")?;
-            }
-
-            write!(f, ">")?;
-        }
-
-        write!(f, "(")?;
-
-        if let Some(value_parameters) = &self.value_parameters {
-            for (index, (identifier, r#type)) in value_parameters.iter().enumerate() {
-                if index > 0 {
-                    write!(f, ", ")?;
-                }
-
-                write!(f, "{identifier}: {type}")?;
-            }
-        }
-
-        write!(f, ")")?;
-
-        if let Some(return_type) = &self.return_type {
-            write!(f, " -> {return_type}")?;
-        }
-
-        Ok(())
-    }
-}
-
-#[derive(Clone, Debug, Eq, PartialEq, Serialize, Deserialize)]
-pub enum StructType {
-    Unit { name: u8 },
-    Tuple { name: u8, fields: Vec<Type> },
-    Fields { name: u8, fields: HashMap<u8, Type> },
-}
-
-impl StructType {
-    pub fn name(&self) -> u8 {
-        match self {
-            StructType::Unit { name } => *name,
-            StructType::Tuple { name, .. } => *name,
-            StructType::Fields { name, .. } => *name,
-        }
-    }
-}
-
-impl Display for StructType {
-    fn fmt(&self, f: &mut Formatter<'_>) -> fmt::Result {
-        match self {
-            StructType::Unit { name } => write!(f, "{name}"),
-            StructType::Tuple { name, fields } => {
-                write!(f, "{name}(")?;
-
-                for (index, field) in fields.iter().enumerate() {
-                    write!(f, "{field}")?;
-
-                    if index != fields.len() - 1 {
-                        write!(f, ", ")?;
-                    }
-                }
-
-                write!(f, ")")
-            }
-            StructType::Fields { name, fields } => {
-                write!(f, "{name} {{")?;
-
-                for (index, (identifier, r#type)) in fields.iter().enumerate() {
-                    write!(f, "{identifier}: {type}")?;
-
-                    if index != fields.len() - 1 {
-                        write!(f, ", ")?;
-                    }
-                }
-
-                write!(f, "}}")
-            }
-        }
-    }
-}
-
-impl PartialOrd for StructType {
-    fn partial_cmp(&self, other: &Self) -> Option<Ordering> {
-        Some(self.cmp(other))
-    }
-}
-
-impl Ord for StructType {
-    fn cmp(&self, other: &Self) -> Ordering {
-        match (self, other) {
-            (StructType::Unit { name: left_name }, StructType::Unit { name: right_name }) => {
-                left_name.cmp(right_name)
-            }
-            (StructType::Unit { .. }, _) => Ordering::Greater,
-            (
-                StructType::Tuple {
-                    name: left_name,
-                    fields: left_fields,
-                },
-                StructType::Tuple {
-                    name: right_name,
-                    fields: right_fields,
-                },
-            ) => {
-                let name_cmp = left_name.cmp(right_name);
-
-                if name_cmp == Ordering::Equal {
-                    left_fields.cmp(right_fields)
-                } else {
-                    name_cmp
-                }
-            }
-            (StructType::Tuple { .. }, _) => Ordering::Greater,
-            (
-                StructType::Fields {
-                    name: left_name,
-                    fields: left_fields,
-                },
-                StructType::Fields {
-                    name: right_name,
-                    fields: right_fields,
-                },
-            ) => {
-                let name_cmp = left_name.cmp(right_name);
-
-                if name_cmp == Ordering::Equal {
-                    let len_cmp = left_fields.len().cmp(&right_fields.len());
-
-                    if len_cmp == Ordering::Equal {
-                        left_fields.iter().cmp(right_fields.iter())
-                    } else {
-                        len_cmp
-                    }
-                } else {
-                    name_cmp
-                }
-            }
-            (StructType::Fields { .. }, _) => Ordering::Greater,
-        }
-    }
-}
-
-#[derive(Clone, Debug, Eq, PartialEq, PartialOrd, Ord, Serialize, Deserialize)]
-pub struct EnumType {
-    pub name: u8,
-    pub variants: Vec<StructType>,
-}
-
-impl Display for EnumType {
-    fn fmt(&self, f: &mut Formatter<'_>) -> fmt::Result {
-        let EnumType { name, variants } = self;
-
-        write!(f, "enum {name} {{ ")?;
-
-        for (index, variant) in variants.iter().enumerate() {
-            write!(f, "{variant}")?;
-
-            if index != self.variants.len() - 1 {
-                write!(f, ", ")?;
-            }
-        }
-
-        write!(f, " }}")
-    }
-}
-
-#[derive(Clone, Debug, Eq, PartialEq, PartialOrd, Ord, Serialize, Deserialize)]
-pub enum RangeableType {
-    Byte,
-    Character,
-    Float,
-    Integer,
-}
-
-impl Display for RangeableType {
-    fn fmt(&self, f: &mut Formatter<'_>) -> fmt::Result {
-        match self {
-            RangeableType::Byte => Type::Byte.fmt(f),
-            RangeableType::Character => Type::Character.fmt(f),
-            RangeableType::Float => Type::Float.fmt(f),
-            RangeableType::Integer => Type::Integer.fmt(f),
-        }
-    }
-}
-
-#[derive(Clone, Debug, Eq, PartialEq, Serialize, Deserialize)]
-pub struct TypeConflict {
-    pub expected: Type,
-    pub actual: Type,
-}
-
-#[cfg(test)]
-mod tests {
-    use super::*;
-
-    #[test]
-    fn check_type_any() {
-        let foo = Type::Any;
-        let bar = Type::Any;
-
-        foo.check(&bar).unwrap();
-    }
-
-    #[test]
-    fn check_type_boolean() {
-        let foo = Type::Boolean;
-        let bar = Type::Boolean;
-
-        foo.check(&bar).unwrap();
-    }
-
-    #[test]
-    fn check_type_byte() {
-        let foo = Type::Byte;
-        let bar = Type::Byte;
-
-        foo.check(&bar).unwrap();
-    }
-
-    #[test]
-    fn check_type_character() {
-        let foo = Type::Character;
-        let bar = Type::Character;
-
-        foo.check(&bar).unwrap();
-    }
-
-    #[test]
-    fn errors() {
-        let foo = Type::Integer;
-        let bar = Type::String { length: None };
-
-        assert_eq!(
-            foo.check(&bar),
-            Err(TypeConflict {
-                actual: bar.clone(),
-                expected: foo.clone()
-            })
-        );
-        assert_eq!(
-            bar.check(&foo),
-            Err(TypeConflict {
-                actual: foo.clone(),
-                expected: bar.clone()
-            })
-        );
-
-        let types = [
-            Type::Boolean,
-            Type::Float,
-            Type::Integer,
-            Type::List {
-                item_type: Box::new(Type::Integer),
-                length: 42,
-            },
-            Type::Range {
-                r#type: RangeableType::Integer,
-            },
-            Type::String { length: None },
-        ];
-
-        for left in types.clone() {
-            for right in types.clone() {
-                if left == right {
-                    continue;
-                }
-
-                assert_eq!(
-                    left.check(&right),
-                    Err(TypeConflict {
-                        actual: right.clone(),
-                        expected: left.clone()
-                    })
-                );
-            }
-        }
-    }
-}

dust-lang/src/value.rs

@@ -1,767 +0,0 @@
-//! Dust value representation
-//!
-//! # Examples
-//!
-//! Each type of value has a corresponding method for instantiation:
-//!
-//! ```
-//! # use dust_lang::Value;
-//! let boolean = Value::boolean(true);
-//! let float = Value::float(3.14);
-//! let integer = Value::integer(42);
-//! let string = Value::string("Hello, world!");
-//! ```
-//!
-//! Values have a type, which can be retrieved using the `r#type` method:
-//!
-//! ```
-//! # use dust_lang::*;
-//! let value = Value::integer(42);
-//!
-//! assert_eq!(value.r#type(), Type::Integer);
-//! ```
-use std::{
-    cmp::Ordering,
-    fmt::{self, Debug, Display, Formatter},
-    ops::{Range, RangeInclusive},
-};
-
-use serde::{Deserialize, Serialize};
-
-use crate::{Chunk, FunctionType, RangeableType, Type};
-
-/// Dust value representation
-///
-/// See the [module-level documentation][self] for more.
-#[derive(Debug, Eq, PartialEq, PartialOrd, Ord, Serialize, Deserialize)]
-pub enum Value {
-    Concrete(ConcreteValue),
-    Abstract(AbstractValue),
-}
-
-impl Value {
-    pub fn boolean(value: bool) -> Self {
-        Value::Concrete(ConcreteValue::Boolean(value))
-    }
-
-    pub fn byte(value: u8) -> Self {
-        Value::Concrete(ConcreteValue::Byte(value))
-    }
-
-    pub fn character(value: char) -> Self {
-        Value::Concrete(ConcreteValue::Character(value))
-    }
-
-    pub fn float(value: f64) -> Self {
-        Value::Concrete(ConcreteValue::Float(value))
-    }
-
-    pub fn function(body: Chunk, r#type: FunctionType) -> Self {
-        Value::Concrete(ConcreteValue::Function(Function {
-            chunk: body,
-            r#type: Type::Function(r#type),
-        }))
-    }
-
-    pub fn integer<T: Into<i64>>(into_i64: T) -> Self {
-        Value::Concrete(ConcreteValue::Integer(into_i64.into()))
-    }
-
-    pub fn list<T: Into<Vec<Value>>>(items: T) -> Self {
-        Value::Concrete(ConcreteValue::List(items.into()))
-    }
-
-    pub fn abstract_list(start: u8, end: u8, item_type: Type) -> Self {
-        Value::Abstract(AbstractValue::List {
-            start,
-            end,
-            item_type,
-        })
-    }
-
-    pub fn string<T: ToString>(to_string: T) -> Self {
-        Value::Concrete(ConcreteValue::String(to_string.to_string()))
-    }
-
-    pub fn as_string(&self) -> Option<&String> {
-        if let Value::Concrete(ConcreteValue::String(string)) = self {
-            Some(string)
-        } else {
-            None
-        }
-    }
-
-    pub fn is_function(&self) -> bool {
-        matches!(self, Value::Concrete(ConcreteValue::Function(_)))
-    }
-
-    pub fn r#type(&self) -> Type {
-        match self {
-            Value::Concrete(data) => data.r#type(),
-            Value::Abstract(AbstractValue::List {
-                start,
-                end,
-                item_type,
-            }) => {
-                let length = (end - start + 1) as usize;
-
-                Type::List {
-                    length,
-                    item_type: Box::new(item_type.clone()),
-                }
-            }
-        }
-    }
-
-    pub fn add(&self, other: &Value) -> Result<Value, ValueError> {
-        use ConcreteValue::*;
-        use Value::*;
-
-        let sum = match (self, other) {
-            (Concrete(Byte(left)), Concrete(Byte(right))) => {
-                Value::byte(left.saturating_add(*right))
-            }
-            (Concrete(Float(left)), Concrete(Float(right))) => Value::float(left + right),
-            (Concrete(Integer(left)), Concrete(Integer(right))) => {
-                Value::integer(left.saturating_add(*right))
-            }
-            (Concrete(String(left)), Concrete(String(right))) => {
-                Value::string(format!("{}{}", left, right))
-            }
-            _ => return Err(ValueError::CannotAdd(self.clone(), other.clone())),
-        };
-
-        Ok(sum)
-    }
-
-    pub fn subtract(&self, other: &Value) -> Result<Value, ValueError> {
-        use ConcreteValue::*;
-        use Value::*;
-
-        let different = match (self, other) {
-            (Concrete(Byte(left)), Concrete(Byte(right))) => {
-                Value::byte(left.saturating_sub(*right))
-            }
-            (Concrete(Float(left)), Concrete(Float(right))) => Value::float(left - right),
-            (Concrete(Integer(left)), Concrete(Integer(right))) => {
-                Value::integer(left.saturating_sub(*right))
-            }
-            _ => return Err(ValueError::CannotSubtract(self.clone(), other.clone())),
-        };
-
-        Ok(different)
-    }
-
-    pub fn multiply(&self, other: &Value) -> Result<Value, ValueError> {
-        use ConcreteValue::*;
-        use Value::*;
-
-        let product = match (self, other) {
-            (Concrete(Byte(left)), Concrete(Byte(right))) => {
-                Value::byte(left.saturating_mul(*right))
-            }
-            (Concrete(Float(left)), Concrete(Float(right))) => Value::float(left * right),
-            (Concrete(Integer(left)), Concrete(Integer(right))) => {
-                Value::integer(left.saturating_mul(*right))
-            }
-            _ => return Err(ValueError::CannotAdd(self.clone(), other.clone())),
-        };
-
-        Ok(product)
-    }
-
-    pub fn divide(&self, other: &Value) -> Result<Value, ValueError> {
-        use ConcreteValue::*;
-        use Value::*;
-
-        let product = match (self, other) {
-            (Concrete(Byte(left)), Concrete(Byte(right))) => {
-                Value::byte(left.saturating_div(*right))
-            }
-            (Concrete(Float(left)), Concrete(Float(right))) => Value::float(left / right),
-            (Concrete(Integer(left)), Concrete(Integer(right))) => {
-                Value::integer(left.saturating_div(*right))
-            }
-            _ => return Err(ValueError::CannotDivide(self.clone(), other.clone())),
-        };
-
-        Ok(product)
-    }
-
-    pub fn modulo(&self, other: &Value) -> Result<Value, ValueError> {
-        use ConcreteValue::*;
-        use Value::*;
-
-        let product = match (self, other) {
-            (Concrete(Byte(left)), Concrete(Byte(right))) => Value::byte(left % right),
-            (Concrete(Float(left)), Concrete(Float(right))) => Value::float(left % right),
-            (Concrete(Integer(left)), Concrete(Integer(right))) => Value::integer(left % right),
-            _ => return Err(ValueError::CannotModulo(self.clone(), other.clone())),
-        };
-
-        Ok(product)
-    }
-
-    pub fn less_than(&self, other: &Value) -> Result<Value, ValueError> {
-        let (left, right) = match (self, other) {
-            (Value::Concrete(left), Value::Concrete(right)) => (left, right),
-            _ => return Err(ValueError::CannotCompare(self.clone(), other.clone())),
-        };
-
-        Ok(Value::boolean(left < right))
-    }
-
-    pub fn less_than_or_equal(&self, other: &Value) -> Result<Value, ValueError> {
-        let (left, right) = match (self, other) {
-            (Value::Concrete(left), Value::Concrete(right)) => (left, right),
-            _ => return Err(ValueError::CannotCompare(self.clone(), other.clone())),
-        };
-
-        Ok(Value::boolean(left <= right))
-    }
-
-    pub fn equal(&self, other: &Value) -> Result<Value, ValueError> {
-        let (left, right) = match (self, other) {
-            (Value::Concrete(left), Value::Concrete(right)) => (left, right),
-            _ => return Err(ValueError::CannotCompare(self.clone(), other.clone())),
-        };
-
-        Ok(Value::boolean(left == right))
-    }
-
-    pub fn negate(&self) -> Result<Value, ValueError> {
-        use ConcreteValue::*;
-        use Value::*;
-
-        let negated = match self {
-            Concrete(Integer(integer)) => Value::integer(-integer),
-            Concrete(Float(float)) => Value::float(-float),
-            _ => return Err(ValueError::CannotNot(self.clone())),
-        };
-
-        Ok(negated)
-    }
-
-    pub fn not(&self) -> Result<Value, ValueError> {
-        use ConcreteValue::*;
-        use Value::*;
-
-        let not = match self {
-            Concrete(Boolean(boolean)) => Value::boolean(!boolean),
-            Concrete(Byte(byte)) => Value::byte(!byte),
-            Concrete(Integer(integer)) => Value::integer(!integer),
-            _ => return Err(ValueError::CannotNot(self.clone())),
-        };
-
-        Ok(not)
-    }
-}
-
-impl From<bool> for Value {
-    fn from(value: bool) -> Self {
-        Value::boolean(value)
-    }
-}
-
-impl From<u8> for Value {
-    fn from(value: u8) -> Self {
-        Value::byte(value)
-    }
-}
-
-impl From<char> for Value {
-    fn from(value: char) -> Self {
-        Value::character(value)
-    }
-}
-
-impl From<f64> for Value {
-    fn from(value: f64) -> Self {
-        Value::float(value)
-    }
-}
-
-impl From<i32> for Value {
-    fn from(value: i32) -> Self {
-        Value::integer(value as i64)
-    }
-}
-
-impl From<i64> for Value {
-    fn from(value: i64) -> Self {
-        Value::integer(value)
-    }
-}
-
-impl From<String> for Value {
-    fn from(value: String) -> Self {
-        Value::string(value)
-    }
-}
-
-impl From<&str> for Value {
-    fn from(str: &str) -> Self {
-        Value::string(str)
-    }
-}
-
-impl Clone for Value {
-    fn clone(&self) -> Self {
-        log::trace!("Cloning value {self}");
-
-        match self {
-            Value::Abstract(object) => Value::Abstract(object.clone()),
-            Value::Concrete(concrete) => Value::Concrete(concrete.clone()),
-        }
-    }
-}
-
-impl Display for Value {
-    fn fmt(&self, f: &mut Formatter) -> fmt::Result {
-        match self {
-            Value::Abstract(object) => write!(f, "{object}"),
-            Value::Concrete(concrete) => write!(f, "{concrete}"),
-        }
-    }
-}
-
-/// Value representation that can be resolved to a concrete value by the VM.
-#[derive(Clone, Debug, PartialEq, Eq, PartialOrd, Ord, Serialize, Deserialize)]
-pub enum AbstractValue {
-    List { start: u8, end: u8, item_type: Type },
-}
-
-impl Display for AbstractValue {
-    fn fmt(&self, f: &mut Formatter<'_>) -> fmt::Result {
-        match self {
-            AbstractValue::List { start, end, .. } => {
-                write!(f, "List [R{}..=R{}]", start, end)
-            }
-        }
-    }
-}
-
-#[derive(Clone, Debug, PartialEq, Deserialize, Serialize)]
-pub enum ConcreteValue {
-    Boolean(bool),
-    Byte(u8),
-    Character(char),
-    Float(f64),
-    Function(Function),
-    Integer(i64),
-    List(Vec<Value>),
-    Range(RangeValue),
-    String(String),
-}
-
-impl ConcreteValue {
-    pub fn r#type(&self) -> Type {
-        match self {
-            ConcreteValue::Boolean(_) => Type::Boolean,
-            ConcreteValue::Byte(_) => Type::Byte,
-            ConcreteValue::Character(_) => Type::Character,
-            ConcreteValue::Float(_) => Type::Float,
-            ConcreteValue::Function(Function { r#type, .. }) => r#type.clone(),
-            ConcreteValue::Integer(_) => Type::Integer,
-            ConcreteValue::List(list) => Type::List {
-                item_type: list
-                    .first()
-                    .map(|value| Box::new(value.r#type()))
-                    .unwrap_or_else(|| Box::new(Type::Any)),
-                length: list.len(),
-            },
-            ConcreteValue::Range(range) => range.r#type(),
-            ConcreteValue::String(string) => Type::String {
-                length: Some(string.len()),
-            },
-        }
-    }
-
-    pub fn is_rangeable(&self) -> bool {
-        matches!(
-            self,
-            ConcreteValue::Integer(_)
-                | ConcreteValue::Float(_)
-                | ConcreteValue::Character(_)
-                | ConcreteValue::Byte(_)
-        )
-    }
-}
-
-impl Display for ConcreteValue {
-    fn fmt(&self, f: &mut Formatter) -> fmt::Result {
-        match self {
-            ConcreteValue::Boolean(boolean) => write!(f, "{boolean}"),
-            ConcreteValue::Byte(byte) => write!(f, "0x{byte:02x}"),
-            ConcreteValue::Character(character) => write!(f, "{character}"),
-            ConcreteValue::Float(float) => {
-                write!(f, "{float}")?;
-
-                if float.fract() == 0.0 {
-                    write!(f, ".0")?;
-                }
-
-                Ok(())
-            }
-            ConcreteValue::Function(Function { r#type, .. }) => {
-                write!(f, "{}", r#type)
-            }
-            ConcreteValue::Integer(integer) => write!(f, "{integer}"),
-            ConcreteValue::List(items) => {
-                write!(f, "[")?;
-
-                for (index, item) in items.iter().enumerate() {
-                    if index > 0 {
-                        write!(f, ", ")?;
-                    }
-
-                    write!(f, "{item}")?;
-                }
-
-                write!(f, "]")
-            }
-            ConcreteValue::Range(range_value) => {
-                write!(f, "{range_value}")
-            }
-            ConcreteValue::String(string) => write!(f, "{string}"),
-        }
-    }
-}
-
-impl Eq for ConcreteValue {}
-
-impl PartialOrd for ConcreteValue {
-    fn partial_cmp(&self, other: &Self) -> Option<Ordering> {
-        Some(self.cmp(other))
-    }
-}
-
-impl Ord for ConcreteValue {
-    fn cmp(&self, other: &Self) -> Ordering {
-        match (self, other) {
-            (ConcreteValue::Boolean(left), ConcreteValue::Boolean(right)) => left.cmp(right),
-            (ConcreteValue::Boolean(_), _) => Ordering::Greater,
-            (ConcreteValue::Byte(left), ConcreteValue::Byte(right)) => left.cmp(right),
-            (ConcreteValue::Byte(_), _) => Ordering::Greater,
-            (ConcreteValue::Character(left), ConcreteValue::Character(right)) => left.cmp(right),
-            (ConcreteValue::Character(_), _) => Ordering::Greater,
-            (ConcreteValue::Float(left), ConcreteValue::Float(right)) => {
-                if left.is_nan() && right.is_nan() {
-                    Ordering::Equal
-                } else if left.is_nan() {
-                    Ordering::Less
-                } else if right.is_nan() {
-                    Ordering::Greater
-                } else {
-                    left.partial_cmp(right).unwrap()
-                }
-            }
-            (ConcreteValue::Float(_), _) => Ordering::Greater,
-            (ConcreteValue::Function(left), ConcreteValue::Function(right)) => left.cmp(right),
-            (ConcreteValue::Function(_), _) => Ordering::Greater,
-            (ConcreteValue::Integer(left), ConcreteValue::Integer(right)) => left.cmp(right),
-            (ConcreteValue::Integer(_), _) => Ordering::Greater,
-            (ConcreteValue::List(left), ConcreteValue::List(right)) => left.cmp(right),
-            (ConcreteValue::List(_), _) => Ordering::Greater,
-            (ConcreteValue::Range(left), ConcreteValue::Range(right)) => left.cmp(right),
-            (ConcreteValue::Range(_), _) => Ordering::Greater,
-            (ConcreteValue::String(left), ConcreteValue::String(right)) => left.cmp(right),
-            (ConcreteValue::String(_), _) => Ordering::Greater,
-        }
-    }
-}
-
-#[derive(Clone, Debug, Eq, PartialEq, PartialOrd, Ord, Serialize, Deserialize)]
-pub struct Function {
-    chunk: Chunk,
-    r#type: Type,
-}
-
-impl Function {
-    pub fn new(chunk: Chunk, r#type: Type) -> Self {
-        Self { chunk, r#type }
-    }
-
-    pub fn chunk(&self) -> &Chunk {
-        &self.chunk
-    }
-
-    pub fn chunk_mut(&mut self) -> &mut Chunk {
-        &mut self.chunk
-    }
-
-    pub fn take_chunk(self) -> Chunk {
-        self.chunk
-    }
-
-    pub fn r#type(&self) -> &Type {
-        &self.r#type
-    }
-}
-
-impl Display for Function {
-    fn fmt(&self, f: &mut Formatter) -> fmt::Result {
-        write!(f, "{}", self.r#type)
-    }
-}
-
-#[derive(Clone, Debug, PartialEq, Serialize, Deserialize)]
-pub enum RangeValue {
-    ByteRange(Range<u8>),
-    ByteRangeInclusive(RangeInclusive<u8>),
-    CharacterRange(Range<char>),
-    CharacterRangeInclusive(RangeInclusive<char>),
-    FloatRange(Range<f64>),
-    FloatRangeInclusive(RangeInclusive<f64>),
-    IntegerRange(Range<i64>),
-    IntegerRangeInclusive(RangeInclusive<i64>),
-}
-
-impl RangeValue {
-    pub fn r#type(&self) -> Type {
-        let inner_type = match self {
-            RangeValue::ByteRange(_) => RangeableType::Byte,
-            RangeValue::ByteRangeInclusive(_) => RangeableType::Byte,
-            RangeValue::CharacterRange(_) => RangeableType::Character,
-            RangeValue::CharacterRangeInclusive(_) => RangeableType::Character,
-            RangeValue::FloatRange(_) => RangeableType::Float,
-            RangeValue::FloatRangeInclusive(_) => RangeableType::Float,
-            RangeValue::IntegerRange(_) => RangeableType::Integer,
-            RangeValue::IntegerRangeInclusive(_) => RangeableType::Integer,
-        };
-
-        Type::Range { r#type: inner_type }
-    }
-}
-
-impl From<Range<u8>> for RangeValue {
-    fn from(range: Range<u8>) -> Self {
-        RangeValue::ByteRange(range)
-    }
-}
-
-impl From<RangeInclusive<u8>> for RangeValue {
-    fn from(range: RangeInclusive<u8>) -> Self {
-        RangeValue::ByteRangeInclusive(range)
-    }
-}
-
-impl From<Range<char>> for RangeValue {
-    fn from(range: Range<char>) -> Self {
-        RangeValue::CharacterRange(range)
-    }
-}
-
-impl From<RangeInclusive<char>> for RangeValue {
-    fn from(range: RangeInclusive<char>) -> Self {
-        RangeValue::CharacterRangeInclusive(range)
-    }
-}
-
-impl From<Range<f64>> for RangeValue {
-    fn from(range: Range<f64>) -> Self {
-        RangeValue::FloatRange(range)
-    }
-}
-
-impl From<RangeInclusive<f64>> for RangeValue {
-    fn from(range: RangeInclusive<f64>) -> Self {
-        RangeValue::FloatRangeInclusive(range)
-    }
-}
-
-impl From<Range<i32>> for RangeValue {
-    fn from(range: Range<i32>) -> Self {
-        RangeValue::IntegerRange(range.start as i64..range.end as i64)
-    }
-}
-
-impl From<RangeInclusive<i32>> for RangeValue {
-    fn from(range: RangeInclusive<i32>) -> Self {
-        RangeValue::IntegerRangeInclusive(*range.start() as i64..=*range.end() as i64)
-    }
-}
-
-impl From<Range<i64>> for RangeValue {
-    fn from(range: Range<i64>) -> Self {
-        RangeValue::IntegerRange(range)
-    }
-}
-
-impl From<RangeInclusive<i64>> for RangeValue {
-    fn from(range: RangeInclusive<i64>) -> Self {
-        RangeValue::IntegerRangeInclusive(range)
-    }
-}
-
-impl Display for RangeValue {
-    fn fmt(&self, f: &mut Formatter) -> fmt::Result {
-        match self {
-            RangeValue::ByteRange(range) => write!(f, "{}..{}", range.start, range.end),
-            RangeValue::ByteRangeInclusive(range) => {
-                write!(f, "{}..={}", range.start(), range.end())
-            }
-            RangeValue::CharacterRange(range) => write!(f, "{}..{}", range.start, range.end),
-            RangeValue::CharacterRangeInclusive(range) => {
-                write!(f, "{}..={}", range.start(), range.end())
-            }
-            RangeValue::FloatRange(range) => write!(f, "{}..{}", range.start, range.end),
-            RangeValue::FloatRangeInclusive(range) => {
-                write!(f, "{}..={}", range.start(), range.end())
-            }
-            RangeValue::IntegerRange(range) => write!(f, "{}..{}", range.start, range.end),
-            RangeValue::IntegerRangeInclusive(range) => {
-                write!(f, "{}..={}", range.start(), range.end())
-            }
-        }
-    }
-}
-
-impl Eq for RangeValue {}
-
-impl PartialOrd for RangeValue {
-    fn partial_cmp(&self, other: &Self) -> Option<Ordering> {
-        Some(self.cmp(other))
-    }
-}
-
-impl Ord for RangeValue {
-    fn cmp(&self, other: &Self) -> Ordering {
-        match (self, other) {
-            (RangeValue::ByteRange(left), RangeValue::ByteRange(right)) => {
-                let start_cmp = left.start.cmp(&right.start);
-
-                if start_cmp != Ordering::Equal {
-                    start_cmp
-                } else {
-                    left.end.cmp(&right.end)
-                }
-            }
-            (RangeValue::ByteRange(_), _) => Ordering::Greater,
-            (RangeValue::ByteRangeInclusive(left), RangeValue::ByteRangeInclusive(right)) => {
-                let start_cmp = left.start().cmp(right.start());
-
-                if start_cmp != Ordering::Equal {
-                    start_cmp
-                } else {
-                    left.end().cmp(right.end())
-                }
-            }
-            (RangeValue::ByteRangeInclusive(_), _) => Ordering::Greater,
-            (RangeValue::CharacterRange(left), RangeValue::CharacterRange(right)) => {
-                let start_cmp = left.start.cmp(&right.start);
-
-                if start_cmp != Ordering::Equal {
-                    start_cmp
-                } else {
-                    left.end.cmp(&right.end)
-                }
-            }
-            (RangeValue::CharacterRange(_), _) => Ordering::Greater,
-            (
-                RangeValue::CharacterRangeInclusive(left),
-                RangeValue::CharacterRangeInclusive(right),
-            ) => {
-                let start_cmp = left.start().cmp(right.start());
-
-                if start_cmp != Ordering::Equal {
-                    start_cmp
-                } else {
-                    left.end().cmp(right.end())
-                }
-            }
-            (RangeValue::CharacterRangeInclusive(_), _) => Ordering::Greater,
-            (RangeValue::FloatRange(left), RangeValue::FloatRange(right)) => {
-                let start_cmp = left.start.to_bits().cmp(&right.start.to_bits());
-
-                if start_cmp != Ordering::Equal {
-                    start_cmp
-                } else {
-                    left.end.to_bits().cmp(&right.end.to_bits())
-                }
-            }
-            (RangeValue::FloatRange(_), _) => Ordering::Greater,
-            (RangeValue::FloatRangeInclusive(left), RangeValue::FloatRangeInclusive(right)) => {
-                let start_cmp = left.start().to_bits().cmp(&right.start().to_bits());
-
-                if start_cmp != Ordering::Equal {
-                    start_cmp
-                } else {
-                    left.end().to_bits().cmp(&right.end().to_bits())
-                }
-            }
-            (RangeValue::FloatRangeInclusive(_), _) => Ordering::Greater,
-            (RangeValue::IntegerRange(left), RangeValue::IntegerRange(right)) => {
-                let start_cmp = left.start.cmp(&right.start);
-
-                if start_cmp != Ordering::Equal {
-                    start_cmp
-                } else {
-                    left.end.cmp(&right.end)
-                }
-            }
-            (RangeValue::IntegerRange(_), _) => Ordering::Greater,
-            (RangeValue::IntegerRangeInclusive(left), RangeValue::IntegerRangeInclusive(right)) => {
-                let start_cmp = left.start().cmp(right.start());
-
-                if start_cmp != Ordering::Equal {
-                    start_cmp
-                } else {
-                    left.end().cmp(right.end())
-                }
-            }
-            (RangeValue::IntegerRangeInclusive(_), _) => Ordering::Greater,
-        }
-    }
-}
-
-#[derive(Clone, Debug, PartialEq)]
-pub enum ValueError {
-    CannotAdd(Value, Value),
-    CannotAnd(Value, Value),
-    CannotCompare(Value, Value),
-    CannotDivide(Value, Value),
-    CannotModulo(Value, Value),
-    CannotMultiply(Value, Value),
-    CannotNegate(Value),
-    CannotNot(Value),
-    CannotSubtract(Value, Value),
-    CannotOr(Value, Value),
-}
-
-impl Display for ValueError {
-    fn fmt(&self, f: &mut Formatter<'_>) -> fmt::Result {
-        match self {
-            ValueError::CannotAdd(left, right) => {
-                write!(f, "Cannot add {left} and {right}")
-            }
-            ValueError::CannotAnd(left, right) => {
-                write!(f, "Cannot use logical AND operation on {left} and {right}")
-            }
-            ValueError::CannotCompare(left, right) => {
-                write!(f, "Cannot compare {left} and {right}")
-            }
-            ValueError::CannotDivide(left, right) => {
-                write!(f, "Cannot divide {left} by {right}")
-            }
-            ValueError::CannotModulo(left, right) => {
-                write!(f, "Cannot use modulo operation on {left} and {right}")
-            }
-            ValueError::CannotMultiply(left, right) => {
-                write!(f, "Cannot multiply {left} by {right}")
-            }
-            ValueError::CannotNegate(value) => {
-                write!(f, "Cannot negate {value}")
-            }
-            ValueError::CannotNot(value) => {
-                write!(f, "Cannot use logical NOT operation on {value}")
-            }
-            ValueError::CannotSubtract(left, right) => {
-                write!(f, "Cannot subtract {right} from {left}")
-            }
-            ValueError::CannotOr(left, right) => {
-                write!(f, "Cannot use logical OR operation on {left} and {right}")
-            }
-        }
-    }
-}

dust-lang/src/vm.rs

@@ -1,765 +0,0 @@
-//! Virtual machine and errors
-use std::{
-    cmp::Ordering,
-    fmt::{self, Display, Formatter},
-    ops::Range,
-};
-
-use crate::{
-    compile, value::ConcreteValue, AnnotatedError, Chunk, ChunkError, DustError, FunctionType,
-    Instruction, Local, NativeFunction, NativeFunctionError, Operation, Span, Type, Value,
-    ValueError,
-};
-
-pub fn run(source: &str) -> Result<Option<Value>, DustError> {
-    let mut chunk = compile(source)?;
-    let mut vm = Vm::new(&mut chunk, None);
-
-    vm.run()
-        .map(|option| option.cloned())
-        .map_err(|error| DustError::Runtime { error, source })
-}
-
-pub fn run_and_display_output(source: &str) {
-    match run(source) {
-        Ok(Some(value)) => println!("{}", value),
-        Ok(None) => {}
-        Err(error) => eprintln!("{}", error.report()),
-    }
-}
-
-/// Dust virtual machine.
-///
-/// See the [module-level documentation](index.html) for more information.
-#[derive(Debug, Eq, PartialEq)]
-pub struct Vm<'chunk, 'parent> {
-    ip: usize,
-    chunk: &'chunk mut Chunk,
-    stack: Vec<Register>,
-    last_assigned_register: Option<u8>,
-    parent: Option<&'parent Vm<'chunk, 'parent>>,
-}
-
-impl<'chunk, 'parent> Vm<'chunk, 'parent> {
-    const STACK_LIMIT: usize = u16::MAX as usize;
-
-    pub fn new(chunk: &'chunk mut Chunk, parent: Option<&'parent Vm<'chunk, 'parent>>) -> Self {
-        Self {
-            ip: 0,
-            chunk,
-            stack: Vec::new(),
-            last_assigned_register: None,
-            parent,
-        }
-    }
-
-    pub fn run(&mut self) -> Result<Option<&Value>, VmError> {
-        // DRY helper to get constant or register values for binary operations
-        fn get_arguments<'a>(
-            vm: &'a mut Vm,
-            instruction: Instruction,
-            position: Span,
-        ) -> Result<(&'a Value, &'a Value), VmError> {
-            let left = if instruction.b_is_constant() {
-                vm.get_constant(instruction.b(), position)?
-            } else {
-                vm.open_register(instruction.b(), position)?
-            };
-            let right = if instruction.c_is_constant() {
-                vm.get_constant(instruction.c(), position)?
-            } else {
-                vm.open_register(instruction.c(), position)?
-            };
-
-            Ok((left, right))
-        }
-
-        while let Ok((instruction, position)) = self.read(Span(0, 0)).copied() {
-            log::info!(
-                "{} | {} | {} | {}",
-                self.ip - 1,
-                position,
-                instruction.operation(),
-                instruction.disassembly_info(self.chunk)
-            );
-
-            match instruction.operation() {
-                Operation::Move => {
-                    let to_register = instruction.a();
-                    let from_register = instruction.b();
-                    let from_register_has_value = self
-                        .stack
-                        .get(from_register as usize)
-                        .is_some_and(|register| !matches!(register, Register::Empty));
-
-                    if from_register_has_value {
-                        self.set_register(
-                            to_register,
-                            Register::StackPointer(from_register),
-                            position,
-                        )?;
-                    }
-                }
-                Operation::Close => {
-                    let from_register = instruction.b();
-                    let to_register = instruction.c();
-
-                    if self.stack.len() < to_register as usize {
-                        return Err(VmError::StackUnderflow { position });
-                    }
-
-                    for register_index in from_register..to_register {
-                        self.stack[register_index as usize] = Register::Empty;
-                    }
-                }
-                Operation::LoadBoolean => {
-                    let to_register = instruction.a();
-                    let boolean = instruction.b_as_boolean();
-                    let jump = instruction.c_as_boolean();
-                    let value = Value::boolean(boolean);
-
-                    self.set_register(to_register, Register::Value(value), position)?;
-
-                    if jump {
-                        self.ip += 1;
-                    }
-                }
-                Operation::LoadConstant => {
-                    let to_register = instruction.a();
-                    let from_constant = instruction.b();
-                    let jump = instruction.c_as_boolean();
-
-                    self.set_register(
-                        to_register,
-                        Register::ConstantPointer(from_constant),
-                        position,
-                    )?;
-
-                    if jump {
-                        self.ip += 1
-                    }
-                }
-                Operation::LoadList => {
-                    let to_register = instruction.a();
-                    let start_register = instruction.b();
-                    let item_type = (start_register..to_register)
-                        .find_map(|register_index| {
-                            if let Ok(value) = self.open_register(register_index, position) {
-                                Some(value.r#type())
-                            } else {
-                                None
-                            }
-                        })
-                        .unwrap_or(Type::Any);
-                    let value = Value::abstract_list(start_register, to_register, item_type);
-
-                    self.set_register(to_register, Register::Value(value), position)?;
-                }
-                Operation::LoadSelf => {
-                    let to_register = instruction.a();
-                    let value = Value::function(
-                        self.chunk.clone(),
-                        FunctionType {
-                            type_parameters: None,
-                            value_parameters: None,
-                            return_type: None,
-                        },
-                    );
-
-                    self.set_register(to_register, Register::Value(value), position)?;
-                }
-                Operation::DefineLocal => {
-                    let from_register = instruction.a();
-                    let to_local = instruction.b();
-
-                    self.define_local(to_local, from_register, position)?;
-                }
-                Operation::GetLocal => {
-                    let to_register = instruction.a();
-                    let local_index = instruction.b();
-                    let local = self.get_local(local_index, position)?;
-
-                    self.set_register(
-                        to_register,
-                        Register::StackPointer(local.register_index),
-                        position,
-                    )?;
-                }
-                Operation::SetLocal => {
-                    let register = instruction.a();
-                    let local_index = instruction.b();
-
-                    self.define_local(local_index, register, position)?;
-                }
-                Operation::Add => {
-                    let to_register = instruction.a();
-                    let (left, right) = get_arguments(self, instruction, position)?;
-                    let sum = left
-                        .add(right)
-                        .map_err(|error| VmError::Value { error, position })?;
-
-                    self.set_register(to_register, Register::Value(sum), position)?;
-                }
-                Operation::Subtract => {
-                    let to_register = instruction.a();
-                    let (left, right) = get_arguments(self, instruction, position)?;
-                    let difference = left
-                        .subtract(right)
-                        .map_err(|error| VmError::Value { error, position })?;
-
-                    self.set_register(to_register, Register::Value(difference), position)?;
-                }
-                Operation::Multiply => {
-                    let to_register = instruction.a();
-                    let (left, right) = get_arguments(self, instruction, position)?;
-                    let product = left
-                        .multiply(right)
-                        .map_err(|error| VmError::Value { error, position })?;
-
-                    self.set_register(to_register, Register::Value(product), position)?;
-                }
-                Operation::Divide => {
-                    let to_register = instruction.a();
-                    let (left, right) = get_arguments(self, instruction, position)?;
-                    let quotient = left
-                        .divide(right)
-                        .map_err(|error| VmError::Value { error, position })?;
-
-                    self.set_register(to_register, Register::Value(quotient), position)?;
-                }
-                Operation::Modulo => {
-                    let to_register = instruction.a();
-                    let (left, right) = get_arguments(self, instruction, position)?;
-                    let remainder = left
-                        .modulo(right)
-                        .map_err(|error| VmError::Value { error, position })?;
-
-                    self.set_register(to_register, Register::Value(remainder), position)?;
-                }
-                Operation::Test => {
-                    let register = instruction.a();
-                    let test_value = instruction.c_as_boolean();
-                    let value = self.open_register(register, position)?;
-                    let boolean = if let Value::Concrete(ConcreteValue::Boolean(boolean)) = value {
-                        *boolean
-                    } else {
-                        return Err(VmError::ExpectedBoolean {
-                            found: value.clone(),
-                            position,
-                        });
-                    };
-
-                    if boolean != test_value {
-                        self.ip += 1;
-                    }
-                }
-                Operation::TestSet => todo!(),
-                Operation::Equal => {
-                    debug_assert_eq!(
-                        self.get_instruction(self.ip, position)?.0.operation(),
-                        Operation::Jump
-                    );
-
-                    let (left, right) = get_arguments(self, instruction, position)?;
-                    let equal_result = left
-                        .equal(right)
-                        .map_err(|error| VmError::Value { error, position })?;
-                    let boolean =
-                        if let Value::Concrete(ConcreteValue::Boolean(boolean)) = equal_result {
-                            boolean
-                        } else {
-                            return Err(VmError::ExpectedBoolean {
-                                found: equal_result.clone(),
-                                position,
-                            });
-                        };
-                    let compare_to = instruction.a_as_boolean();
-
-                    if boolean == compare_to {
-                        self.ip += 1;
-                    } else {
-                        let (jump, _) = self.get_instruction(self.ip, position)?;
-                        let jump_distance = jump.a();
-                        let is_positive = jump.b_as_boolean();
-                        let new_ip = if is_positive {
-                            self.ip + jump_distance as usize
-                        } else {
-                            self.ip - jump_distance as usize
-                        };
-
-                        self.ip = new_ip;
-                    }
-                }
-                Operation::Less => {
-                    debug_assert_eq!(
-                        self.get_instruction(self.ip, position)?.0.operation(),
-                        Operation::Jump
-                    );
-
-                    let (left, right) = get_arguments(self, instruction, position)?;
-                    let less_result = left
-                        .less_than(right)
-                        .map_err(|error| VmError::Value { error, position })?;
-                    let boolean =
-                        if let Value::Concrete(ConcreteValue::Boolean(boolean)) = less_result {
-                            boolean
-                        } else {
-                            return Err(VmError::ExpectedBoolean {
-                                found: less_result.clone(),
-                                position,
-                            });
-                        };
-                    let compare_to = instruction.a_as_boolean();
-
-                    if boolean == compare_to {
-                        self.ip += 1;
-                    } else {
-                        let jump = self.get_instruction(self.ip, position)?.0;
-                        let jump_distance = jump.a();
-                        let is_positive = jump.b_as_boolean();
-                        let new_ip = if is_positive {
-                            self.ip + jump_distance as usize
-                        } else {
-                            self.ip - jump_distance as usize
-                        };
-
-                        self.ip = new_ip;
-                    }
-                }
-                Operation::LessEqual => {
-                    debug_assert_eq!(
-                        self.get_instruction(self.ip, position)?.0.operation(),
-                        Operation::Jump
-                    );
-
-                    let (left, right) = get_arguments(self, instruction, position)?;
-                    let less_or_equal_result = left
-                        .less_than_or_equal(right)
-                        .map_err(|error| VmError::Value { error, position })?;
-                    let boolean = if let Value::Concrete(ConcreteValue::Boolean(boolean)) =
-                        less_or_equal_result
-                    {
-                        boolean
-                    } else {
-                        return Err(VmError::ExpectedBoolean {
-                            found: less_or_equal_result.clone(),
-                            position,
-                        });
-                    };
-                    let compare_to = instruction.a_as_boolean();
-
-                    if boolean == compare_to {
-                        self.ip += 1;
-                    } else {
-                        let jump = self.get_instruction(self.ip, position)?.0;
-                        let jump_distance = jump.a();
-                        let is_positive = jump.b_as_boolean();
-                        let new_ip = if is_positive {
-                            self.ip + jump_distance as usize
-                        } else {
-                            self.ip - jump_distance as usize
-                        };
-
-                        self.ip = new_ip;
-                    }
-                }
-                Operation::Negate => {
-                    let value = if instruction.b_is_constant() {
-                        self.get_constant(instruction.b(), position)?
-                    } else {
-                        self.open_register(instruction.b(), position)?
-                    };
-                    let negated = value
-                        .negate()
-                        .map_err(|error| VmError::Value { error, position })?;
-
-                    self.set_register(instruction.a(), Register::Value(negated), position)?;
-                }
-                Operation::Not => {
-                    let value = if instruction.b_is_constant() {
-                        self.get_constant(instruction.b(), position)?
-                    } else {
-                        self.open_register(instruction.b(), position)?
-                    };
-                    let not = value
-                        .not()
-                        .map_err(|error| VmError::Value { error, position })?;
-
-                    self.set_register(instruction.a(), Register::Value(not), position)?;
-                }
-                Operation::Jump => {
-                    let jump_distance = instruction.b();
-                    let is_positive = instruction.c_as_boolean();
-                    let new_ip = if is_positive {
-                        self.ip + jump_distance as usize
-                    } else {
-                        self.ip - jump_distance as usize - 1
-                    };
-                    self.ip = new_ip;
-                }
-                Operation::Call => {
-                    let to_register = instruction.a();
-                    let function_register = instruction.b();
-                    let argument_count = instruction.c();
-                    let value = self.open_register(function_register, position)?.clone();
-                    let mut function =
-                        if let Value::Concrete(ConcreteValue::Function(function)) = value {
-                            function
-                        } else {
-                            return Err(VmError::ExpectedFunction {
-                                found: value,
-                                position,
-                            });
-                        };
-                    let mut function_vm = Vm::new(function.chunk_mut(), Some(self));
-                    let first_argument_index = function_register + 1;
-
-                    for argument_index in
-                        first_argument_index..first_argument_index + argument_count
-                    {
-                        let top_of_stack = function_vm.stack.len() as u8;
-
-                        function_vm.set_register(
-                            top_of_stack,
-                            Register::ParentStackPointer(argument_index),
-                            position,
-                        )?
-                    }
-
-                    let return_value = function_vm.run()?.cloned();
-
-                    if let Some(value) = return_value {
-                        self.set_register(to_register, Register::Value(value), position)?;
-                    }
-                }
-                Operation::CallNative => {
-                    let native_function = NativeFunction::from(instruction.b());
-                    let return_value = native_function.call(instruction, self, position)?;
-
-                    if let Some(value) = return_value {
-                        let to_register = instruction.a();
-
-                        self.set_register(to_register, Register::Value(value), position)?;
-                    }
-                }
-                Operation::Return => {
-                    let should_return_value = instruction.b_as_boolean();
-
-                    if !should_return_value {
-                        return Ok(None);
-                    }
-
-                    let return_value = if let Some(register_index) = self.last_assigned_register {
-                        self.open_register(register_index, position)?
-                    } else {
-                        return Err(VmError::StackUnderflow { position });
-                    };
-
-                    return Ok(Some(return_value));
-                }
-            }
-        }
-
-        Ok(None)
-    }
-
-    fn set_register(
-        &mut self,
-        to_register: u8,
-        register: Register,
-        position: Span,
-    ) -> Result<(), VmError> {
-        self.last_assigned_register = Some(to_register);
-
-        let length = self.stack.len();
-        let to_register = to_register as usize;
-
-        if length == Self::STACK_LIMIT {
-            return Err(VmError::StackOverflow { position });
-        }
-
-        match to_register.cmp(&length) {
-            Ordering::Less => {
-                log::trace!("Change R{to_register} to {register}");
-
-                self.stack[to_register] = register;
-
-                Ok(())
-            }
-            Ordering::Equal => {
-                log::trace!("Set R{to_register} to {register}");
-
-                self.stack.push(register);
-
-                Ok(())
-            }
-            Ordering::Greater => {
-                let difference = to_register - length;
-
-                for index in 0..difference {
-                    log::trace!("Set R{index} to {register}");
-
-                    self.stack.push(Register::Empty);
-                }
-
-                log::trace!("Set R{to_register} to {register}");
-
-                self.stack.push(register);
-
-                Ok(())
-            }
-        }
-    }
-
-    fn get_constant(&self, index: u8, position: Span) -> Result<&Value, VmError> {
-        self.chunk
-            .get_constant(index)
-            .map_err(|error| VmError::Chunk { error, position })
-    }
-
-    pub fn open_register(&self, register_index: u8, position: Span) -> Result<&Value, VmError> {
-        let register_index = register_index as usize;
-        let register =
-            self.stack
-                .get(register_index)
-                .ok_or_else(|| VmError::RegisterIndexOutOfBounds {
-                    index: register_index,
-                    position,
-                })?;
-
-        match register {
-            Register::Value(value) => Ok(value),
-            Register::StackPointer(register_index) => self.open_register(*register_index, position),
-            Register::ConstantPointer(constant_index) => {
-                self.get_constant(*constant_index, position)
-            }
-            Register::ParentStackPointer(register_index) => {
-                let parent = self
-                    .parent
-                    .as_ref()
-                    .ok_or(VmError::ExpectedParent { position })?;
-
-                parent.open_register(*register_index, position)
-            }
-            Register::ParentConstantPointer(constant_index) => {
-                let parent = self
-                    .parent
-                    .as_ref()
-                    .ok_or(VmError::ExpectedParent { position })?;
-
-                parent.get_constant(*constant_index, position)
-            }
-            Register::Empty => Err(VmError::EmptyRegister {
-                index: register_index,
-                position,
-            }),
-        }
-    }
-
-    pub fn open_nonempty_registers(
-        &self,
-        register_index_range: Range<u8>,
-        position: Span,
-    ) -> Result<Vec<&Value>, VmError> {
-        let mut values = Vec::with_capacity(register_index_range.len());
-
-        for register_index in register_index_range.clone() {
-            let register_index = register_index as usize;
-            let register = self.stack.get(register_index).ok_or_else(|| {
-                VmError::RegisterIndexOutOfBounds {
-                    index: register_index,
-                    position,
-                }
-            })?;
-
-            let value = match register {
-                Register::Value(value) => value,
-                Register::StackPointer(register_index) => {
-                    self.open_register(*register_index, position)?
-                }
-                Register::ConstantPointer(constant_index) => {
-                    self.get_constant(*constant_index, position)?
-                }
-                Register::ParentStackPointer(register_index) => {
-                    let parent = self
-                        .parent
-                        .as_ref()
-                        .ok_or(VmError::ExpectedParent { position })?;
-
-                    parent.open_register(*register_index, position)?
-                }
-                Register::ParentConstantPointer(constant_index) => {
-                    let parent = self
-                        .parent
-                        .as_ref()
-                        .ok_or(VmError::ExpectedParent { position })?;
-
-                    parent.get_constant(*constant_index, position)?
-                }
-                Register::Empty => continue,
-            };
-
-            values.push(value);
-        }
-
-        if values.is_empty() {
-            Err(VmError::EmptyRegisters {
-                indexes: register_index_range,
-                position,
-            })
-        } else {
-            Ok(values)
-        }
-    }
-
-    fn read(&mut self, position: Span) -> Result<&(Instruction, Span), VmError> {
-        self.chunk
-            .expect_not_poisoned()
-            .map_err(|error| VmError::Chunk { error, position })?;
-
-        let max_ip = self.chunk.len() - 1;
-
-        if self.ip > max_ip {
-            return self.get_instruction(max_ip, position);
-        } else {
-            self.ip += 1;
-        }
-
-        self.get_instruction(self.ip - 1, position)
-    }
-
-    fn define_local(
-        &mut self,
-        local_index: u8,
-        register_index: u8,
-        position: Span,
-    ) -> Result<(), VmError> {
-        let local = self
-            .chunk
-            .get_local_mut(local_index)
-            .map_err(|error| VmError::Chunk { error, position })?;
-
-        log::debug!("Define local L{}", local_index);
-
-        local.register_index = register_index;
-
-        Ok(())
-    }
-
-    fn get_local(&self, local_index: u8, position: Span) -> Result<&Local, VmError> {
-        self.chunk
-            .get_local(local_index)
-            .map_err(|error| VmError::Chunk { error, position })
-    }
-
-    fn get_instruction(
-        &self,
-        index: usize,
-        position: Span,
-    ) -> Result<&(Instruction, Span), VmError> {
-        self.chunk
-            .get_instruction(index)
-            .map_err(|error| VmError::Chunk { error, position })
-    }
-}
-
-#[derive(Debug, Eq, PartialEq)]
-enum Register {
-    Empty,
-    Value(Value),
-    StackPointer(u8),
-    ConstantPointer(u8),
-    ParentStackPointer(u8),
-    ParentConstantPointer(u8),
-}
-
-impl Display for Register {
-    fn fmt(&self, f: &mut Formatter) -> fmt::Result {
-        match self {
-            Self::Empty => write!(f, "empty"),
-            Self::Value(value) => write!(f, "{}", value),
-            Self::StackPointer(index) => write!(f, "R{}", index),
-            Self::ConstantPointer(index) => write!(f, "C{}", index),
-            Self::ParentStackPointer(index) => write!(f, "PR{}", index),
-            Self::ParentConstantPointer(index) => write!(f, "PC{}", index),
-        }
-    }
-}
-
-#[derive(Clone, Debug, PartialEq)]
-pub enum VmError {
-    // Stack errors
-    StackOverflow { position: Span },
-    StackUnderflow { position: Span },
-
-    // Register errors
-    EmptyRegister { index: usize, position: Span },
-    EmptyRegisters { indexes: Range<u8>, position: Span },
-    RegisterIndexOutOfBounds { index: usize, position: Span },
-
-    // Execution errors
-    ExpectedBoolean { found: Value, position: Span },
-    ExpectedFunction { found: Value, position: Span },
-    ExpectedParent { position: Span },
-
-    // Wrappers for foreign errors
-    Chunk { error: ChunkError, position: Span },
-    NativeFunction(NativeFunctionError),
-    Value { error: ValueError, position: Span },
-}
-
-impl AnnotatedError for VmError {
-    fn title() -> &'static str {
-        "Runtime Error"
-    }
-
-    fn description(&self) -> &'static str {
-        match self {
-            Self::Chunk { .. } => "Chunk error",
-            Self::EmptyRegister { .. } => "Empty register",
-            Self::EmptyRegisters { .. } => "Empty registers",
-            Self::ExpectedBoolean { .. } => "Expected boolean",
-            Self::ExpectedFunction { .. } => "Expected function",
-            Self::ExpectedParent { .. } => "Expected parent",
-            Self::NativeFunction(error) => error.description(),
-            Self::RegisterIndexOutOfBounds { .. } => "Register index out of bounds",
-            Self::StackOverflow { .. } => "Stack overflow",
-            Self::StackUnderflow { .. } => "Stack underflow",
-            Self::Value { .. } => "Value error",
-        }
-    }
-
-    fn details(&self) -> Option<String> {
-        match self {
-            Self::Chunk { error, .. } => Some(error.to_string()),
-            Self::EmptyRegister { index, .. } => Some(format!("Register R{index} is empty")),
-            Self::EmptyRegisters { indexes: range, .. } => Some(format!(
-                "Registers R{} to R{} are empty",
-                range.start, range.end
-            )),
-            Self::ExpectedFunction { found, .. } => Some(format!("{found} is not a function")),
-            Self::RegisterIndexOutOfBounds { index, .. } => {
-                Some(format!("Register {index} does not exist"))
-            }
-            Self::NativeFunction(error) => error.details(),
-            Self::Value { error, .. } => Some(error.to_string()),
-            _ => None,
-        }
-    }
-
-    fn position(&self) -> Span {
-        match self {
-            Self::Chunk { position, .. } => *position,
-            Self::EmptyRegister { position, .. } => *position,
-            Self::EmptyRegisters { position, .. } => *position,
-            Self::ExpectedBoolean { position, .. } => *position,
-            Self::ExpectedFunction { position, .. } => *position,
-            Self::ExpectedParent { position } => *position,
-            Self::NativeFunction(error) => error.position(),
-            Self::RegisterIndexOutOfBounds { position, .. } => *position,
-            Self::StackOverflow { position } => *position,
-            Self::StackUnderflow { position } => *position,
-            Self::Value { position, .. } => *position,
-        }
-    }
-}

dust-lang/tests/basic.rs

@@ -1,66 +0,0 @@
-use dust_lang::*;
-
-#[test]
-fn constant() {
-    let source = "42";
-
-    assert_eq!(
-        compile(source),
-        Ok(Chunk::with_data(
-            None,
-            vec![
-                (Instruction::load_constant(0, 0, false), Span(0, 2)),
-                (Instruction::r#return(true), Span(2, 2))
-            ],
-            vec![Value::integer(42)],
-            vec![]
-        ))
-    );
-
-    assert_eq!(run(source), Ok(Some(Value::integer(42))));
-}
-
-#[test]
-fn empty() {
-    let source = "";
-
-    assert_eq!(
-        compile(source),
-        Ok(Chunk::with_data(
-            None,
-            vec![(Instruction::r#return(false), Span(0, 0))],
-            vec![],
-            vec![]
-        ))
-    );
-    assert_eq!(run(source), Ok(None));
-}
-
-#[test]
-fn parentheses_precedence() {
-    let source = "(1 + 2) * 3";
-
-    assert_eq!(
-        compile(source),
-        Ok(Chunk::with_data(
-            None,
-            vec![
-                (
-                    *Instruction::add(0, 0, 1)
-                        .set_b_is_constant()
-                        .set_c_is_constant(),
-                    Span(3, 4)
-                ),
-                (
-                    *Instruction::multiply(1, 0, 2).set_c_is_constant(),
-                    Span(8, 9)
-                ),
-                (Instruction::r#return(true), Span(11, 11)),
-            ],
-            vec![Value::integer(1), Value::integer(2), Value::integer(3)],
-            vec![]
-        ))
-    );
-
-    assert_eq!(run(source), Ok(Some(Value::integer(9))));
-}

dust-lang/tests/comparison.rs

@@ -1,169 +0,0 @@
-use dust_lang::*;
-
-#[test]
-fn equal() {
-    let source = "1 == 2";
-
-    assert_eq!(
-        compile(source),
-        Ok(Chunk::with_data(
-            None,
-            vec![
-                (
-                    *Instruction::equal(true, 0, 1)
-                        .set_b_is_constant()
-                        .set_c_is_constant(),
-                    Span(2, 4)
-                ),
-                (Instruction::jump(1, true), Span(2, 4)),
-                (Instruction::load_boolean(0, true, true), Span(2, 4)),
-                (Instruction::load_boolean(0, false, false), Span(2, 4)),
-                (Instruction::r#return(true), Span(6, 6)),
-            ],
-            vec![Value::integer(1), Value::integer(2)],
-            vec![]
-        )),
-    );
-
-    assert_eq!(run(source), Ok(Some(Value::boolean(false))));
-}
-
-#[test]
-fn greater() {
-    let source = "1 > 2";
-
-    assert_eq!(
-        compile(source),
-        Ok(Chunk::with_data(
-            None,
-            vec![
-                (
-                    *Instruction::less_equal(false, 0, 1)
-                        .set_b_is_constant()
-                        .set_c_is_constant(),
-                    Span(2, 3)
-                ),
-                (Instruction::jump(1, true), Span(2, 3)),
-                (Instruction::load_boolean(0, true, true), Span(2, 3)),
-                (Instruction::load_boolean(0, false, false), Span(2, 3)),
-                (Instruction::r#return(true), Span(5, 5)),
-            ],
-            vec![Value::integer(1), Value::integer(2)],
-            vec![]
-        )),
-    );
-
-    assert_eq!(run(source), Ok(Some(Value::boolean(false))));
-}
-
-#[test]
-fn greater_than_or_equal() {
-    let source = "1 >= 2";
-
-    assert_eq!(
-        compile(source),
-        Ok(Chunk::with_data(
-            None,
-            vec![
-                (
-                    *Instruction::less(false, 0, 1)
-                        .set_b_is_constant()
-                        .set_c_is_constant(),
-                    Span(2, 4)
-                ),
-                (Instruction::jump(1, true), Span(2, 4)),
-                (Instruction::load_boolean(0, true, true), Span(2, 4)),
-                (Instruction::load_boolean(0, false, false), Span(2, 4)),
-                (Instruction::r#return(true), Span(6, 6)),
-            ],
-            vec![Value::integer(1), Value::integer(2)],
-            vec![]
-        )),
-    );
-
-    assert_eq!(run(source), Ok(Some(Value::boolean(false))));
-}
-
-#[test]
-fn less_than() {
-    let source = "1 < 2";
-
-    assert_eq!(
-        compile(source),
-        Ok(Chunk::with_data(
-            None,
-            vec![
-                (
-                    *Instruction::less(true, 0, 1)
-                        .set_b_is_constant()
-                        .set_c_is_constant(),
-                    Span(2, 3)
-                ),
-                (Instruction::jump(1, true), Span(2, 3)),
-                (Instruction::load_boolean(0, true, true), Span(2, 3)),
-                (Instruction::load_boolean(0, false, false), Span(2, 3)),
-                (Instruction::r#return(true), Span(5, 5)),
-            ],
-            vec![Value::integer(1), Value::integer(2)],
-            vec![]
-        )),
-    );
-
-    assert_eq!(run(source), Ok(Some(Value::boolean(true))));
-}
-
-#[test]
-fn less_than_or_equal() {
-    let source = "1 <= 2";
-
-    assert_eq!(
-        compile(source),
-        Ok(Chunk::with_data(
-            None,
-            vec![
-                (
-                    *Instruction::less_equal(true, 0, 1)
-                        .set_b_is_constant()
-                        .set_c_is_constant(),
-                    Span(2, 4)
-                ),
-                (Instruction::jump(1, true), Span(2, 4)),
-                (Instruction::load_boolean(0, true, true), Span(2, 4)),
-                (Instruction::load_boolean(0, false, false), Span(2, 4)),
-                (Instruction::r#return(true), Span(6, 6)),
-            ],
-            vec![Value::integer(1), Value::integer(2)],
-            vec![]
-        )),
-    );
-
-    assert_eq!(run(source), Ok(Some(Value::boolean(true))));
-}
-
-#[test]
-fn not_equal() {
-    let source = "1 != 2";
-
-    assert_eq!(
-        compile(source),
-        Ok(Chunk::with_data(
-            None,
-            vec![
-                (
-                    *Instruction::equal(false, 0, 1)
-                        .set_b_is_constant()
-                        .set_c_is_constant(),
-                    Span(2, 4)
-                ),
-                (Instruction::jump(1, true), Span(2, 4)),
-                (Instruction::load_boolean(0, true, true), Span(2, 4)),
-                (Instruction::load_boolean(0, false, false), Span(2, 4)),
-                (Instruction::r#return(true), Span(6, 6)),
-            ],
-            vec![Value::integer(1), Value::integer(2)],
-            vec![]
-        )),
-    );
-
-    assert_eq!(run(source), Ok(Some(Value::boolean(true))));
-}

dust-lang/tests/control_flow.rs

@@ -1,420 +0,0 @@
-use dust_lang::*;
-
-#[test]
-fn equality_assignment_long() {
-    let source = "let a = if 4 == 4 { true } else { false }; a";
-
-    assert_eq!(
-        compile(source),
-        Ok(Chunk::with_data(
-            None,
-            vec![
-                (
-                    *Instruction::equal(true, 0, 0)
-                        .set_b_is_constant()
-                        .set_c_is_constant(),
-                    Span(13, 15)
-                ),
-                (Instruction::jump(1, true), Span(18, 19)),
-                (Instruction::load_boolean(0, true, true), Span(20, 24)),
-                (Instruction::load_boolean(0, false, false), Span(34, 39)),
-                (Instruction::define_local(0, 0, false), Span(4, 5)),
-                (Instruction::get_local(1, 0), Span(43, 44)),
-                (Instruction::r#return(true), Span(44, 44)),
-            ],
-            vec![Value::integer(4), Value::string("a")],
-            vec![Local::new(
-                1,
-                None,
-                false,
-                Scope {
-                    depth: 0,
-                    block_index: 0
-                },
-                0
-            )]
-        )),
-    );
-
-    assert_eq!(run(source), Ok(Some(Value::boolean(true))));
-}
-
-#[test]
-fn equality_assignment_short() {
-    let source = "let a = 4 == 4 a";
-
-    assert_eq!(
-        compile(source),
-        Ok(Chunk::with_data(
-            None,
-            vec![
-                (
-                    *Instruction::equal(true, 0, 0)
-                        .set_b_is_constant()
-                        .set_c_is_constant(),
-                    Span(10, 12)
-                ),
-                (Instruction::jump(1, true), Span(10, 12)),
-                (Instruction::load_boolean(0, true, true), Span(10, 12)),
-                (Instruction::load_boolean(0, false, false), Span(10, 12)),
-                (Instruction::define_local(0, 0, false), Span(4, 5)),
-                (Instruction::get_local(1, 0), Span(15, 16)),
-                (Instruction::r#return(true), Span(16, 16)),
-            ],
-            vec![Value::integer(4), Value::string("a")],
-            vec![Local::new(1, None, false, Scope::default(), 0)]
-        )),
-    );
-
-    assert_eq!(run(source), Ok(Some(Value::boolean(true))));
-}
-
-#[test]
-fn if_else_assigment_false() {
-    let source = r#"
-        let a = if 4 == 3 {
-            1; 2; 3; 4;
-            panic()
-        } else {
-            1; 2; 3; 4;
-            42
-        };
-        a"#;
-
-    assert_eq!(
-        compile(source),
-        Ok(Chunk::with_data(
-            None,
-            vec![
-                (
-                    *Instruction::equal(true, 0, 1)
-                        .set_b_is_constant()
-                        .set_c_is_constant(),
-                    Span(22, 24)
-                ),
-                (Instruction::jump(6, true), Span(27, 28)),
-                (Instruction::load_constant(0, 2, false), Span(41, 42)),
-                (Instruction::load_constant(1, 3, false), Span(44, 45)),
-                (Instruction::load_constant(2, 1, false), Span(47, 48)),
-                (Instruction::load_constant(3, 0, false), Span(50, 51)),
-                (
-                    Instruction::call_native(4, NativeFunction::Panic, 0),
-                    Span(65, 72)
-                ),
-                (Instruction::jump(5, true), Span(138, 139)),
-                (Instruction::load_constant(5, 2, false), Span(102, 103)),
-                (Instruction::load_constant(6, 3, false), Span(105, 106)),
-                (Instruction::load_constant(7, 1, false), Span(108, 109)),
-                (Instruction::load_constant(8, 0, false), Span(111, 112)),
-                (Instruction::load_constant(9, 4, false), Span(126, 128)),
-                (Instruction::r#move(9, 4), Span(138, 139)),
-                (Instruction::define_local(9, 0, false), Span(13, 14)),
-                (Instruction::get_local(10, 0), Span(148, 149)),
-                (Instruction::r#return(true), Span(149, 149)),
-            ],
-            vec![
-                Value::integer(4),
-                Value::integer(3),
-                Value::integer(1),
-                Value::integer(2),
-                Value::integer(42),
-                Value::string("a")
-            ],
-            vec![Local::new(5, None, false, Scope::default(), 0)]
-        )),
-    );
-
-    assert_eq!(run(source), Ok(Some(Value::integer(42))));
-}
-
-#[test]
-fn if_else_assigment_true() {
-    let source = r#"
-        let a = if 4 == 4 {
-            1; 2; 3; 4;
-            42
-        } else {
-            1; 2; 3; 4;
-            panic()
-        };
-        a"#;
-
-    assert_eq!(
-        compile(source),
-        Ok(Chunk::with_data(
-            None,
-            vec![
-                (
-                    *Instruction::equal(true, 0, 0)
-                        .set_b_is_constant()
-                        .set_c_is_constant(),
-                    Span(22, 24)
-                ),
-                (Instruction::jump(6, true), Span(27, 28)),
-                (Instruction::load_constant(0, 1, false), Span(41, 42)),
-                (Instruction::load_constant(1, 2, false), Span(44, 45)),
-                (Instruction::load_constant(2, 3, false), Span(47, 48)),
-                (Instruction::load_constant(3, 0, false), Span(50, 51)),
-                (Instruction::load_constant(4, 4, false), Span(65, 67)),
-                (Instruction::jump(5, true), Span(138, 139)),
-                (Instruction::load_constant(5, 1, false), Span(97, 98)),
-                (Instruction::load_constant(6, 2, false), Span(100, 101)),
-                (Instruction::load_constant(7, 3, false), Span(103, 104)),
-                (Instruction::load_constant(8, 0, false), Span(106, 107)),
-                (
-                    Instruction::call_native(9, NativeFunction::Panic, 0),
-                    Span(121, 128)
-                ),
-                (Instruction::r#move(9, 4), Span(138, 139)),
-                (Instruction::define_local(9, 0, false), Span(13, 14)),
-                (Instruction::get_local(10, 0), Span(148, 149)),
-                (Instruction::r#return(true), Span(149, 149)),
-            ],
-            vec![
-                Value::integer(4),
-                Value::integer(1),
-                Value::integer(2),
-                Value::integer(3),
-                Value::integer(42),
-                Value::string("a")
-            ],
-            vec![Local::new(5, None, false, Scope::default(), 0)]
-        )),
-    );
-
-    assert_eq!(run(source), Ok(Some(Value::integer(42))));
-}
-
-#[test]
-fn if_else_complex() {
-    let source = "
-        if 1 == 1 {
-            1; 2; 3; 4;
-        } else {
-            1; 2; 3; 4;
-        }";
-
-    assert_eq!(
-        compile(source),
-        Ok(Chunk::with_data(
-            None,
-            vec![
-                (
-                    *Instruction::equal(true, 0, 0)
-                        .set_b_is_constant()
-                        .set_c_is_constant(),
-                    Span(14, 16)
-                ),
-                (Instruction::jump(5, true), Span(19, 20)),
-                (Instruction::load_constant(0, 0, false), Span(33, 34)),
-                (Instruction::load_constant(1, 1, false), Span(36, 37)),
-                (Instruction::load_constant(2, 2, false), Span(39, 40)),
-                (Instruction::load_constant(3, 3, false), Span(42, 43)),
-                (Instruction::jump(4, true), Span(95, 95)),
-                (Instruction::load_constant(4, 0, false), Span(74, 75)),
-                (Instruction::load_constant(5, 1, false), Span(77, 78)),
-                (Instruction::load_constant(6, 2, false), Span(80, 81)),
-                (Instruction::load_constant(7, 3, false), Span(83, 84)),
-                (Instruction::r#move(7, 3), Span(95, 95)),
-                (Instruction::r#return(false), Span(95, 95)),
-            ],
-            vec![
-                Value::integer(1),
-                Value::integer(2),
-                Value::integer(3),
-                Value::integer(4),
-            ],
-            vec![]
-        ))
-    );
-
-    assert_eq!(run(source), Ok(None));
-}
-
-// #[test]
-// fn if_else_nested() {
-//     let source = r#"
-//         if 0 == 1 {
-//             if 0 == 2 {
-//                 1;
-//             } else {
-//                 2;
-//             }
-//         } else {
-//             if 0 == 3 {
-//                 3;
-//             } else {
-//                 4;
-//             }
-//         }"#;
-
-//     assert_eq!(
-//         parse(source),
-//         Ok(Chunk::with_data(
-//             None,
-//             vec![
-//                 (
-//                     *Instruction::equal(true, 0, 1)
-//                         .set_b_is_constant()
-//                         .set_c_is_constant(),
-//                     Span(14, 16)
-//                 ),
-//                 (Instruction::jump(7, true), Span(14, 16)),
-//                 (
-//                     *Instruction::equal(true, 0, 2)
-//                         .set_b_is_constant()
-//                         .set_c_is_constant(),
-//                     Span(38, 41)
-//                 ),
-//                 (Instruction::jump(3, true), Span(38, 41)),
-//                 (Instruction::load_constant(0, 1, false), Span(61, 62)),
-//                 (Instruction::jump(1, true1), Span(95, 95)),
-//                 (
-//                     *Instruction::equal(true, 0, 3)
-//                         .set_b_is_constant()
-//                         .set_c_is_constant(),
-//                     Span(77, 79)
-//                 ),
-//                 (Instruction::jump(3, true), Span(77, 79)),
-//                 (Instruction::load_constant(0, 2, false), Span(94, 95)),
-//                 (Instruction::jump(1, true1), Span(95, 95)),
-//                 (Instruction::load_constant(0, 3, false), Span(114, 115)),
-//                 (Instruction::jump(1, true1), Span(95, 95)),
-//                 (Instruction::load_constant(0, 4, false), Span(134, 135)),
-//                 (Instruction::r#return(true), Span(146, 146)),
-//             ],
-//             vec![
-//                 Value::integer(0),
-//                 Value::integer(1),
-//                 Value::integer(0),
-//                 Value::integer(2),
-//                 Value::integer(1),
-//                 Value::integer(0),
-//                 Value::integer(3),
-//                 Value::integer(3),
-//                 Value::integer(4)
-//             ],
-//             vec![]
-//         ))
-//     );
-
-//     assert_eq!(run(source), Ok(Some(Value::integer(4))));
-// }
-
-#[test]
-fn if_else_false() {
-    let source = "if 1 == 2 { panic() } else { 42 }";
-
-    assert_eq!(
-        compile(source),
-        Ok(Chunk::with_data(
-            None,
-            vec![
-                (
-                    *Instruction::equal(true, 0, 1)
-                        .set_b_is_constant()
-                        .set_c_is_constant(),
-                    Span(5, 7)
-                ),
-                (Instruction::jump(1, true), Span(10, 11)),
-                (
-                    Instruction::call_native(0, NativeFunction::Panic, 0),
-                    Span(12, 19)
-                ),
-                (Instruction::load_constant(1, 2, true), Span(29, 31)),
-                (Instruction::r#move(1, 0), Span(33, 33)),
-                (Instruction::r#return(true), Span(33, 33)),
-            ],
-            vec![Value::integer(1), Value::integer(2), Value::integer(42)],
-            vec![]
-        )),
-    );
-
-    assert_eq!(run(source), Ok(Some(Value::integer(42))));
-}
-
-#[test]
-fn if_else_true() {
-    let source = "if 1 == 1 { 42 } else { panic() }";
-
-    assert_eq!(
-        compile(source),
-        Ok(Chunk::with_data(
-            None,
-            vec![
-                (
-                    *Instruction::equal(true, 0, 0)
-                        .set_b_is_constant()
-                        .set_c_is_constant(),
-                    Span(5, 7)
-                ),
-                (Instruction::jump(1, true), Span(10, 11)),
-                (Instruction::load_constant(0, 1, true), Span(12, 14)),
-                (
-                    Instruction::call_native(1, NativeFunction::Panic, 0),
-                    Span(24, 31)
-                ),
-                (Instruction::r#move(1, 0), Span(33, 33)),
-                (Instruction::r#return(true), Span(33, 33))
-            ],
-            vec![Value::integer(1), Value::integer(42)],
-            vec![]
-        )),
-    );
-
-    assert_eq!(run(source), Ok(Some(Value::integer(42))));
-}
-
-#[test]
-fn if_false() {
-    let source = "if 1 == 2 { 2 }";
-
-    assert_eq!(
-        compile(source),
-        Ok(Chunk::with_data(
-            None,
-            vec![
-                (
-                    *Instruction::equal(true, 0, 1)
-                        .set_b_is_constant()
-                        .set_c_is_constant(),
-                    Span(5, 7)
-                ),
-                (Instruction::jump(1, true), Span(10, 11)),
-                (Instruction::load_constant(0, 1, false), Span(12, 13)),
-                (Instruction::r#return(false), Span(15, 15))
-            ],
-            vec![Value::integer(1), Value::integer(2)],
-            vec![]
-        )),
-    );
-
-    assert_eq!(run(source), Ok(None));
-}
-
-#[test]
-fn if_true() {
-    let source = "if 1 == 1 { 2 }";
-
-    assert_eq!(
-        compile(source),
-        Ok(Chunk::with_data(
-            None,
-            vec![
-                (
-                    *Instruction::equal(true, 0, 0)
-                        .set_b_is_constant()
-                        .set_c_is_constant(),
-                    Span(5, 7)
-                ),
-                (Instruction::jump(1, true), Span(10, 11)),
-                (Instruction::load_constant(0, 1, false), Span(12, 13)),
-                (Instruction::r#return(false), Span(15, 15))
-            ],
-            vec![Value::integer(1), Value::integer(2)],
-            vec![]
-        )),
-    );
-
-    assert_eq!(run(source), Ok(None));
-}

dust-lang/tests/functions.rs

@@ -1,126 +0,0 @@
-use dust_lang::*;
-
-#[test]
-fn function() {
-    let source = "fn(a: int, b: int) -> int { a + b }";
-
-    assert_eq!(
-        run(source),
-        Ok(Some(Value::function(
-            Chunk::with_data(
-                None,
-                vec![
-                    (Instruction::add(2, 0, 1), Span(30, 31)),
-                    (Instruction::r#return(true), Span(35, 35)),
-                ],
-                vec![Value::string("a"), Value::string("b"),],
-                vec![
-                    Local::new(0, Some(Type::Integer), false, Scope::default(), 0),
-                    Local::new(1, Some(Type::Integer), false, Scope::default(), 1)
-                ]
-            ),
-            FunctionType {
-                type_parameters: None,
-                value_parameters: Some(vec![(0, Type::Integer), (1, Type::Integer)]),
-                return_type: Some(Box::new(Type::Integer)),
-            }
-        )))
-    );
-}
-
-#[test]
-fn function_call() {
-    let source = "fn(a: int, b: int) -> int { a + b }(1, 2)";
-
-    assert_eq!(
-        compile(source),
-        Ok(Chunk::with_data(
-            None,
-            vec![
-                (Instruction::load_constant(0, 0, false), Span(0, 36)),
-                (Instruction::load_constant(1, 1, false), Span(36, 37)),
-                (Instruction::load_constant(2, 2, false), Span(39, 40)),
-                (Instruction::call(3, 0, 2), Span(35, 41)),
-                (Instruction::r#return(true), Span(41, 41)),
-            ],
-            vec![
-                Value::function(
-                    Chunk::with_data(
-                        None,
-                        vec![
-                            (Instruction::add(2, 0, 1), Span(30, 31)),
-                            (Instruction::r#return(true), Span(35, 36)),
-                        ],
-                        vec![Value::string("a"), Value::string("b"),],
-                        vec![
-                            Local::new(0, Some(Type::Integer), false, Scope::default(), 0),
-                            Local::new(1, Some(Type::Integer), false, Scope::default(), 1)
-                        ]
-                    ),
-                    FunctionType {
-                        type_parameters: None,
-                        value_parameters: Some(vec![(0, Type::Integer), (1, Type::Integer)]),
-                        return_type: Some(Box::new(Type::Integer)),
-                    }
-                ),
-                Value::integer(1),
-                Value::integer(2)
-            ],
-            vec![]
-        )),
-    );
-
-    assert_eq!(run(source), Ok(Some(Value::integer(3))));
-}
-
-#[test]
-fn function_declaration() {
-    let source = "fn add (a: int, b: int) -> int { a + b }";
-
-    assert_eq!(
-        compile(source),
-        Ok(Chunk::with_data(
-            None,
-            vec![
-                (Instruction::load_constant(0, 1, false), Span(0, 40)),
-                (Instruction::define_local(0, 0, false), Span(3, 6)),
-                (Instruction::r#return(false), Span(40, 40))
-            ],
-            vec![
-                Value::string("add"),
-                Value::function(
-                    Chunk::with_data(
-                        None,
-                        vec![
-                            (Instruction::add(2, 0, 1), Span(35, 36)),
-                            (Instruction::r#return(true), Span(40, 40)),
-                        ],
-                        vec![Value::string("a"), Value::string("b")],
-                        vec![
-                            Local::new(0, Some(Type::Integer), false, Scope::default(), 0),
-                            Local::new(1, Some(Type::Integer), false, Scope::default(), 1)
-                        ]
-                    ),
-                    FunctionType {
-                        type_parameters: None,
-                        value_parameters: Some(vec![(0, Type::Integer), (1, Type::Integer)]),
-                        return_type: Some(Box::new(Type::Integer)),
-                    },
-                )
-            ],
-            vec![Local::new(
-                0,
-                Some(Type::Function(FunctionType {
-                    type_parameters: None,
-                    value_parameters: Some(vec![(0, Type::Integer), (1, Type::Integer)]),
-                    return_type: Some(Box::new(Type::Integer)),
-                })),
-                false,
-                Scope::default(),
-                0
-            ),],
-        )),
-    );
-
-    assert_eq!(run(source), Ok(None));
-}

dust-lang/tests/lists.rs

@@ -1,127 +0,0 @@
-use dust_lang::*;
-
-#[test]
-fn empty_list() {
-    let source = "[]";
-
-    assert_eq!(
-        compile(source),
-        Ok(Chunk::with_data(
-            None,
-            vec![
-                (Instruction::load_list(0, 0), Span(0, 2)),
-                (Instruction::r#return(true), Span(2, 2)),
-            ],
-            vec![],
-            vec![]
-        )),
-    );
-
-    assert_eq!(run(source), Ok(Some(Value::abstract_list(0, 0, Type::Any))));
-}
-
-#[test]
-fn list() {
-    let source = "[1, 2, 3]";
-
-    assert_eq!(
-        compile(source),
-        Ok(Chunk::with_data(
-            None,
-            vec![
-                (Instruction::load_constant(0, 0, false), Span(1, 2)),
-                (Instruction::load_constant(1, 1, false), Span(4, 5)),
-                (Instruction::load_constant(2, 2, false), Span(7, 8)),
-                (Instruction::load_list(3, 0), Span(0, 9)),
-                (Instruction::r#return(true), Span(9, 9)),
-            ],
-            vec![Value::integer(1), Value::integer(2), Value::integer(3)],
-            vec![]
-        )),
-    );
-
-    assert_eq!(
-        run(source),
-        Ok(Some(Value::abstract_list(0, 3, Type::Integer)))
-    );
-}
-
-#[test]
-fn list_with_complex_expression() {
-    let source = "[1, 2 + 3 - 4 * 5]";
-
-    assert_eq!(
-        compile(source),
-        Ok(Chunk::with_data(
-            None,
-            vec![
-                (Instruction::load_constant(0, 0, false), Span(1, 2)),
-                (
-                    *Instruction::add(1, 1, 2)
-                        .set_b_is_constant()
-                        .set_c_is_constant(),
-                    Span(6, 7)
-                ),
-                (
-                    *Instruction::multiply(2, 3, 4)
-                        .set_b_is_constant()
-                        .set_c_is_constant(),
-                    Span(14, 15)
-                ),
-                (Instruction::subtract(3, 1, 2), Span(10, 11)),
-                (Instruction::close(1, 3), Span(17, 18)),
-                (Instruction::load_list(4, 0), Span(0, 18)),
-                (Instruction::r#return(true), Span(18, 18)),
-            ],
-            vec![
-                Value::integer(1),
-                Value::integer(2),
-                Value::integer(3),
-                Value::integer(4),
-                Value::integer(5)
-            ],
-            vec![]
-        )),
-    );
-
-    assert_eq!(
-        run(source),
-        Ok(Some(Value::abstract_list(0, 4, Type::Integer)))
-    );
-}
-
-#[test]
-fn list_with_simple_expression() {
-    let source = "[1, 2 + 3, 4]";
-
-    assert_eq!(
-        compile(source),
-        Ok(Chunk::with_data(
-            None,
-            vec![
-                (Instruction::load_constant(0, 0, false), Span(1, 2)),
-                (
-                    *Instruction::add(1, 1, 2)
-                        .set_b_is_constant()
-                        .set_c_is_constant(),
-                    Span(6, 7)
-                ),
-                (Instruction::load_constant(2, 3, false), Span(11, 12)),
-                (Instruction::load_list(3, 0), Span(0, 13)),
-                (Instruction::r#return(true), Span(13, 13)),
-            ],
-            vec![
-                Value::integer(1),
-                Value::integer(2),
-                Value::integer(3),
-                Value::integer(4),
-            ],
-            vec![]
-        )),
-    );
-
-    assert_eq!(
-        run(source),
-        Ok(Some(Value::abstract_list(0, 3, Type::Integer)))
-    );
-}

dust-lang/tests/logic.rs

@@ -1,77 +0,0 @@
-use dust_lang::*;
-
-#[test]
-fn and() {
-    let source = "true && false";
-
-    assert_eq!(
-        compile(source),
-        Ok(Chunk::with_data(
-            None,
-            vec![
-                (Instruction::load_boolean(0, true, false), Span(0, 4)),
-                (Instruction::test(0, false), Span(5, 7)),
-                (Instruction::jump(1, true), Span(5, 7)),
-                (Instruction::load_boolean(1, false, false), Span(8, 13)),
-                (Instruction::r#return(true), Span(13, 13)),
-            ],
-            vec![],
-            vec![]
-        ))
-    );
-
-    assert_eq!(run(source), Ok(Some(Value::boolean(false))));
-}
-
-#[test]
-fn or() {
-    let source = "true || false";
-
-    assert_eq!(
-        compile(source),
-        Ok(Chunk::with_data(
-            None,
-            vec![
-                (Instruction::load_boolean(0, true, false), Span(0, 4)),
-                (Instruction::test(0, true), Span(5, 7)),
-                (Instruction::jump(1, true), Span(5, 7)),
-                (Instruction::load_boolean(1, false, false), Span(8, 13)),
-                (Instruction::r#return(true), Span(13, 13)),
-            ],
-            vec![],
-            vec![]
-        ))
-    );
-
-    assert_eq!(run(source), Ok(Some(Value::boolean(true))));
-}
-
-#[test]
-fn variable_and() {
-    let source = "let a = true; let b = false; a && b";
-
-    assert_eq!(
-        compile(source),
-        Ok(Chunk::with_data(
-            None,
-            vec![
-                (Instruction::load_boolean(0, true, false), Span(8, 12)),
-                (Instruction::define_local(0, 0, false), Span(4, 5)),
-                (Instruction::load_boolean(1, false, false), Span(22, 27)),
-                (Instruction::define_local(1, 1, false), Span(18, 19)),
-                (Instruction::get_local(2, 0), Span(29, 30)),
-                (Instruction::test(2, false), Span(31, 33)),
-                (Instruction::jump(1, true), Span(31, 33)),
-                (Instruction::get_local(3, 1), Span(34, 35)),
-                (Instruction::r#return(true), Span(35, 35)),
-            ],
-            vec![Value::string("a"), Value::string("b"),],
-            vec![
-                Local::new(0, None, false, Scope::default(), 0),
-                Local::new(1, None, false, Scope::default(), 1),
-            ]
-        ))
-    );
-
-    assert_eq!(run(source), Ok(Some(Value::boolean(false))));
-}

dust-lang/tests/loops.rs

@@ -1,35 +0,0 @@
-use dust_lang::*;
-
-#[test]
-fn r#while() {
-    let source = "let mut x = 0; while x < 5 { x = x + 1 } x";
-
-    assert_eq!(
-        compile(source),
-        Ok(Chunk::with_data(
-            None,
-            vec![
-                (Instruction::load_constant(0, 0, false), Span(12, 13)),
-                (Instruction::define_local(0, 0, true), Span(8, 9)),
-                (
-                    *Instruction::less(true, 0, 2).set_c_is_constant(),
-                    Span(23, 24)
-                ),
-                (Instruction::jump(2, true), Span(41, 42)),
-                (*Instruction::add(0, 0, 3).set_c_is_constant(), Span(39, 40)),
-                (Instruction::jump(3, false), Span(41, 42)),
-                (Instruction::get_local(1, 0), Span(41, 42)),
-                (Instruction::r#return(true), Span(42, 42)),
-            ],
-            vec![
-                Value::integer(0),
-                Value::string("x"),
-                Value::integer(5),
-                Value::integer(1),
-            ],
-            vec![Local::new(1, None, true, Scope::default(), 0),]
-        )),
-    );
-
-    assert_eq!(run(source), Ok(Some(Value::integer(5))));
-}

dust-lang/tests/math.rs

@@ -1,324 +0,0 @@
-use dust_lang::*;
-
-#[test]
-fn add() {
-    let source = "1 + 2";
-
-    assert_eq!(
-        compile(source),
-        Ok(Chunk::with_data(
-            None,
-            vec![
-                (
-                    *Instruction::add(0, 0, 1)
-                        .set_b_is_constant()
-                        .set_c_is_constant(),
-                    Span(2, 3)
-                ),
-                (Instruction::r#return(true), Span(5, 5))
-            ],
-            vec![Value::integer(1), Value::integer(2)],
-            vec![]
-        ))
-    );
-
-    assert_eq!(run(source), Ok(Some(Value::integer(3))));
-}
-
-#[test]
-fn add_assign() {
-    let source = "let mut a = 1; a += 2; a";
-
-    assert_eq!(
-        compile(source),
-        Ok(Chunk::with_data(
-            None,
-            vec![
-                (Instruction::load_constant(0, 0, false), Span(12, 13)),
-                (Instruction::define_local(0, 0, true), Span(8, 9)),
-                (*Instruction::add(0, 0, 2).set_c_is_constant(), Span(17, 19)),
-                (Instruction::get_local(1, 0), Span(23, 24)),
-                (Instruction::r#return(true), Span(24, 24))
-            ],
-            vec![Value::integer(1), Value::string("a"), Value::integer(2)],
-            vec![Local::new(1, None, true, Scope::default(), 0)]
-        ))
-    );
-
-    assert_eq!(run(source), Ok(Some(Value::integer(3))));
-}
-
-#[test]
-fn add_assign_expects_mutable_variable() {
-    let source = "1 += 2";
-
-    assert_eq!(
-        compile(source),
-        Err(DustError::Compile {
-            error: CompileError::ExpectedMutableVariable {
-                found: Token::Integer("1").to_owned(),
-                position: Span(0, 1)
-            },
-            source
-        })
-    );
-}
-
-// #[test]
-// fn add_expects_integer_float_or_string() {
-//     let source = "true + false";
-
-//     assert_eq!(
-//         parse(source),
-//         Err(DustError::Parse {
-//             error: ParseError::ExpectedIntegerFloatOrString {
-//                 found: Token::True,
-//                 position: Span(0, 3)
-//             },
-//             source
-//         })
-//     );
-// }
-
-#[test]
-fn divide() {
-    let source = "2 / 2";
-
-    assert_eq!(
-        compile(source),
-        Ok(Chunk::with_data(
-            None,
-            vec![
-                (
-                    *Instruction::divide(0, 0, 0)
-                        .set_b_is_constant()
-                        .set_c_is_constant(),
-                    Span(2, 3)
-                ),
-                (Instruction::r#return(true), Span(5, 5))
-            ],
-            vec![Value::integer(2)],
-            vec![]
-        ))
-    );
-
-    assert_eq!(run(source), Ok(Some(Value::integer(1))));
-}
-
-#[test]
-fn divide_assign() {
-    let source = "let mut a = 2; a /= 2; a";
-
-    assert_eq!(
-        compile(source),
-        Ok(Chunk::with_data(
-            None,
-            vec![
-                (Instruction::load_constant(0, 0, false), Span(12, 13)),
-                (Instruction::define_local(0, 0, true), Span(8, 9)),
-                (
-                    *Instruction::divide(0, 0, 0).set_c_is_constant(),
-                    Span(17, 19)
-                ),
-                (Instruction::get_local(1, 0), Span(23, 24)),
-                (Instruction::r#return(true), Span(24, 24))
-            ],
-            vec![Value::integer(2), Value::string("a")],
-            vec![Local::new(1, None, true, Scope::default(), 0)]
-        ))
-    );
-
-    assert_eq!(run(source), Ok(Some(Value::integer(1))));
-}
-
-#[test]
-fn divide_assign_expects_mutable_variable() {
-    let source = "1 -= 2";
-
-    assert_eq!(
-        compile(source),
-        Err(DustError::Compile {
-            error: CompileError::ExpectedMutableVariable {
-                found: Token::Integer("1").to_owned(),
-                position: Span(0, 1)
-            },
-            source
-        })
-    );
-}
-
-#[test]
-fn math_operator_precedence() {
-    let source = "1 + 2 - 3 * 4 / 5";
-
-    assert_eq!(
-        compile(source),
-        Ok(Chunk::with_data(
-            None,
-            vec![
-                (
-                    *Instruction::add(0, 0, 1)
-                        .set_b_is_constant()
-                        .set_c_is_constant(),
-                    Span(2, 3)
-                ),
-                (
-                    *Instruction::multiply(1, 2, 3)
-                        .set_b_is_constant()
-                        .set_c_is_constant(),
-                    Span(10, 11)
-                ),
-                (
-                    *Instruction::divide(2, 1, 4).set_c_is_constant(),
-                    Span(14, 15)
-                ),
-                (Instruction::subtract(3, 0, 2), Span(6, 7)),
-                (Instruction::r#return(true), Span(17, 17)),
-            ],
-            vec![
-                Value::integer(1),
-                Value::integer(2),
-                Value::integer(3),
-                Value::integer(4),
-                Value::integer(5),
-            ],
-            vec![]
-        ))
-    );
-
-    assert_eq!(run(source), Ok(Some(Value::integer(1))));
-}
-
-#[test]
-fn multiply() {
-    let source = "1 * 2";
-
-    assert_eq!(
-        compile(source),
-        Ok(Chunk::with_data(
-            None,
-            vec![
-                (
-                    *Instruction::multiply(0, 0, 1)
-                        .set_b_is_constant()
-                        .set_c_is_constant(),
-                    Span(2, 3)
-                ),
-                (Instruction::r#return(true), Span(5, 5)),
-            ],
-            vec![Value::integer(1), Value::integer(2)],
-            vec![]
-        ))
-    );
-
-    assert_eq!(run(source), Ok(Some(Value::integer(2))));
-}
-
-#[test]
-fn multiply_assign() {
-    let source = "let mut a = 2; a *= 3 a";
-
-    assert_eq!(
-        compile(source),
-        Ok(Chunk::with_data(
-            None,
-            vec![
-                (Instruction::load_constant(0, 0, false), Span(12, 13)),
-                (Instruction::define_local(0, 0, true), Span(8, 9)),
-                (
-                    *Instruction::multiply(0, 0, 2).set_c_is_constant(),
-                    Span(17, 19)
-                ),
-                (Instruction::get_local(1, 0), Span(22, 23)),
-                (Instruction::r#return(true), Span(23, 23))
-            ],
-            vec![Value::integer(2), Value::string("a"), Value::integer(3)],
-            vec![Local::new(1, None, true, Scope::default(), 0),]
-        ))
-    );
-
-    assert_eq!(run(source), Ok(Some(Value::integer(6))));
-}
-
-#[test]
-fn multiply_assign_expects_mutable_variable() {
-    let source = "1 *= 2";
-
-    assert_eq!(
-        compile(source),
-        Err(DustError::Compile {
-            error: CompileError::ExpectedMutableVariable {
-                found: Token::Integer("1").to_owned(),
-                position: Span(0, 1)
-            },
-            source
-        })
-    );
-}
-
-#[test]
-fn subtract() {
-    let source = "1 - 2";
-
-    assert_eq!(
-        compile(source),
-        Ok(Chunk::with_data(
-            None,
-            vec![
-                (
-                    *Instruction::subtract(0, 0, 1)
-                        .set_b_is_constant()
-                        .set_c_is_constant(),
-                    Span(2, 3)
-                ),
-                (Instruction::r#return(true), Span(5, 5)),
-            ],
-            vec![Value::integer(1), Value::integer(2)],
-            vec![]
-        ))
-    );
-
-    assert_eq!(run(source), Ok(Some(Value::integer(-1))));
-}
-
-#[test]
-fn subtract_assign() {
-    let source = "let mut x = 42; x -= 2; x";
-
-    assert_eq!(
-        compile(source),
-        Ok(Chunk::with_data(
-            None,
-            vec![
-                (Instruction::load_constant(0, 0, false), Span(12, 14)),
-                (Instruction::define_local(0, 0, true), Span(8, 9)),
-                (
-                    *Instruction::subtract(0, 0, 2).set_c_is_constant(),
-                    Span(18, 20)
-                ),
-                (Instruction::get_local(1, 0), Span(24, 25)),
-                (Instruction::r#return(true), Span(25, 25)),
-            ],
-            vec![Value::integer(42), Value::string("x"), Value::integer(2)],
-            vec![Local::new(1, None, true, Scope::default(), 0)]
-        )),
-    );
-
-    assert_eq!(run(source), Ok(Some(Value::integer(40))));
-}
-
-#[test]
-fn subtract_assign_expects_mutable_variable() {
-    let source = "1 -= 2";
-
-    assert_eq!(
-        compile(source),
-        Err(DustError::Compile {
-            error: CompileError::ExpectedMutableVariable {
-                found: Token::Integer("1").to_owned(),
-                position: Span(0, 1)
-            },
-            source
-        })
-    );
-}

dust-lang/tests/native_functions.rs

@@ -1,59 +0,0 @@
-use dust_lang::*;
-
-#[test]
-fn panic() {
-    let source = "panic(\"Goodbye world!\", 42)";
-
-    assert_eq!(
-        compile(source),
-        Ok(Chunk::with_data(
-            None,
-            vec![
-                (Instruction::load_constant(0, 0, false), Span(6, 22)),
-                (Instruction::load_constant(1, 1, false), Span(24, 26)),
-                (
-                    Instruction::call_native(2, NativeFunction::Panic, 2),
-                    Span(0, 27)
-                ),
-                (Instruction::r#return(true), Span(27, 27))
-            ],
-            vec![Value::string("Goodbye world!"), Value::integer(42)],
-            vec![]
-        )),
-    );
-
-    assert_eq!(
-        run(source),
-        Err(DustError::Runtime {
-            error: VmError::NativeFunction(NativeFunctionError::Panic {
-                message: Some("Goodbye world! 42".to_string()),
-                position: Span(0, 27)
-            }),
-            source
-        })
-    )
-}
-
-#[test]
-fn to_string() {
-    let source = "to_string(42)";
-
-    assert_eq!(
-        compile(source),
-        Ok(Chunk::with_data(
-            None,
-            vec![
-                (Instruction::load_constant(0, 0, false), Span(10, 12)),
-                (
-                    Instruction::call_native(1, NativeFunction::ToString, 1),
-                    Span(0, 13)
-                ),
-                (Instruction::r#return(true), Span(13, 13))
-            ],
-            vec![Value::integer(42)],
-            vec![]
-        )),
-    );
-
-    assert_eq!(run(source), Ok(Some(Value::string("42"))))
-}

dust-lang/tests/scopes.rs

@@ -1,244 +0,0 @@
-use dust_lang::*;
-
-#[test]
-fn allow_access_to_parent_scope() {
-    let source = r#"
-        let x = 1;
-        {
-            x
-        }
-    "#;
-
-    assert_eq!(run(source), Ok(Some(Value::integer(1))));
-}
-
-#[test]
-fn block_scope() {
-    let source = "
-        let a = 0;
-        {
-            let b = 42;
-            {
-                let c = 1;
-            }
-            let d = 2;
-        }
-        let e = 1;
-    ";
-
-    assert_eq!(
-        compile(source),
-        Ok(Chunk::with_data(
-            None,
-            vec![
-                (Instruction::load_constant(0, 0, false), Span(17, 18)),
-                (Instruction::define_local(0, 0, false), Span(13, 14)),
-                (Instruction::load_constant(1, 2, false), Span(50, 52)),
-                (Instruction::define_local(1, 1, false), Span(46, 47)),
-                (Instruction::load_constant(2, 4, false), Span(92, 93)),
-                (Instruction::define_local(2, 2, false), Span(88, 89)),
-                (Instruction::load_constant(3, 6, false), Span(129, 130)),
-                (Instruction::define_local(3, 3, false), Span(125, 126)),
-                (Instruction::load_constant(4, 4, false), Span(158, 159)),
-                (Instruction::define_local(4, 4, false), Span(154, 155)),
-                (Instruction::r#return(false), Span(165, 165))
-            ],
-            vec![
-                Value::integer(0),
-                Value::string("a"),
-                Value::integer(42),
-                Value::string("b"),
-                Value::integer(1),
-                Value::string("c"),
-                Value::integer(2),
-                Value::string("d"),
-                Value::string("e"),
-            ],
-            vec![
-                Local::new(1, None, false, Scope::new(0, 0), 0),
-                Local::new(3, None, false, Scope::new(1, 1), 1),
-                Local::new(5, None, false, Scope::new(2, 2), 2),
-                Local::new(7, None, false, Scope::new(1, 1), 3),
-                Local::new(8, None, false, Scope::new(0, 0), 4),
-            ]
-        )),
-    );
-
-    assert_eq!(run(source), Ok(None));
-}
-
-#[test]
-fn multiple_block_scopes() {
-    let source = "
-        let a = 0;
-        {
-            let b = 42;
-            {
-                let c = 1;
-            }
-            let d = 2;
-        }
-        let q = 42;
-        {
-            let b = 42;
-            {
-                let c = 1;
-            }
-            let d = 2;
-        }
-        let e = 1;
-    ";
-
-    assert_eq!(
-        compile(source),
-        Ok(Chunk::with_data(
-            None,
-            vec![
-                (Instruction::load_constant(0, 0, false), Span(17, 18)),
-                (Instruction::define_local(0, 0, false), Span(13, 14)),
-                (Instruction::load_constant(1, 2, false), Span(50, 52)),
-                (Instruction::define_local(1, 1, false), Span(46, 47)),
-                (Instruction::load_constant(2, 4, false), Span(92, 93)),
-                (Instruction::define_local(2, 2, false), Span(88, 89)),
-                (Instruction::load_constant(3, 6, false), Span(129, 130)),
-                (Instruction::define_local(3, 3, false), Span(125, 126)),
-                (Instruction::load_constant(4, 2, false), Span(158, 160)),
-                (Instruction::define_local(4, 4, false), Span(154, 155)),
-                (Instruction::load_constant(5, 2, false), Span(192, 194)),
-                (Instruction::define_local(5, 5, false), Span(188, 189)),
-                (Instruction::load_constant(6, 4, false), Span(234, 235)),
-                (Instruction::define_local(6, 6, false), Span(230, 231)),
-                (Instruction::load_constant(7, 6, false), Span(271, 272)),
-                (Instruction::define_local(7, 7, false), Span(267, 268)),
-                (Instruction::load_constant(8, 4, false), Span(300, 301)),
-                (Instruction::define_local(8, 8, false), Span(296, 297)),
-                (Instruction::r#return(false), Span(307, 307))
-            ],
-            vec![
-                Value::integer(0),
-                Value::string("a"),
-                Value::integer(42),
-                Value::string("b"),
-                Value::integer(1),
-                Value::string("c"),
-                Value::integer(2),
-                Value::string("d"),
-                Value::string("q"),
-                Value::string("e"),
-            ],
-            vec![
-                Local::new(1, None, false, Scope::new(0, 0), 0),
-                Local::new(3, None, false, Scope::new(1, 1), 1),
-                Local::new(5, None, false, Scope::new(2, 2), 2),
-                Local::new(7, None, false, Scope::new(1, 1), 3),
-                Local::new(8, None, false, Scope::new(0, 0), 4),
-                Local::new(3, None, false, Scope::new(1, 3), 5),
-                Local::new(5, None, false, Scope::new(2, 4), 6),
-                Local::new(7, None, false, Scope::new(1, 3), 7),
-                Local::new(9, None, false, Scope::new(0, 0), 8),
-            ]
-        )),
-    );
-
-    assert_eq!(run(source), Ok(None));
-}
-
-#[test]
-fn disallow_access_to_child_scope() {
-    let source = r#"
-        {
-            let x = 1;
-        }
-        x
-    "#;
-
-    assert_eq!(
-        run(source),
-        Err(DustError::Compile {
-            error: CompileError::VariableOutOfScope {
-                identifier: "x".to_string(),
-                position: Span(52, 53),
-                variable_scope: Scope::new(1, 1),
-                access_scope: Scope::new(0, 0),
-            },
-            source
-        })
-    );
-}
-
-#[test]
-fn disallow_access_to_child_scope_nested() {
-    let source = r#"
-        {
-            {
-                let x = 1;
-            }
-            x
-        }
-    "#;
-
-    assert_eq!(
-        run(source),
-        Err(DustError::Compile {
-            error: CompileError::VariableOutOfScope {
-                identifier: "x".to_string(),
-                position: Span(78, 79),
-                variable_scope: Scope::new(2, 2),
-                access_scope: Scope::new(1, 1),
-            },
-            source
-        })
-    );
-}
-
-#[test]
-fn disallow_access_to_sibling_scope() {
-    let source = r#"
-        {
-            let x = 1;
-        }
-        {
-            x
-        }
-    "#;
-
-    assert_eq!(
-        run(source),
-        Err(DustError::Compile {
-            error: CompileError::VariableOutOfScope {
-                identifier: "x".to_string(),
-                variable_scope: Scope::new(1, 1),
-                access_scope: Scope::new(1, 2),
-                position: Span(66, 67),
-            },
-            source
-        })
-    );
-}
-
-#[test]
-fn disallow_access_to_sibling_scope_nested() {
-    let source = r#"
-        {
-            {
-                let x = 1;
-            }
-            {
-                x
-            }
-        }
-    "#;
-
-    assert_eq!(
-        run(source),
-        Err(DustError::Compile {
-            error: CompileError::VariableOutOfScope {
-                identifier: "x".to_string(),
-                variable_scope: Scope::new(2, 2),
-                access_scope: Scope::new(2, 3),
-                position: Span(96, 97),
-            },
-            source
-        })
-    );
-}

dust-lang/tests/unary_operations.rs

@@ -1,42 +0,0 @@
-use dust_lang::*;
-
-#[test]
-fn negate() {
-    let source = "-(42)";
-
-    assert_eq!(
-        compile(source),
-        Ok(Chunk::with_data(
-            None,
-            vec![
-                (*Instruction::negate(0, 0).set_b_is_constant(), Span(0, 1)),
-                (Instruction::r#return(true), Span(5, 5)),
-            ],
-            vec![Value::integer(42)],
-            vec![]
-        )),
-    );
-
-    assert_eq!(run(source), Ok(Some(Value::integer(-42))));
-}
-
-#[test]
-fn not() {
-    let source = "!true";
-
-    assert_eq!(
-        compile(source),
-        Ok(Chunk::with_data(
-            None,
-            vec![
-                (Instruction::load_boolean(0, true, false), Span(1, 5)),
-                (Instruction::not(1, 0), Span(0, 1)),
-                (Instruction::r#return(true), Span(5, 5)),
-            ],
-            vec![],
-            vec![]
-        )),
-    );
-
-    assert_eq!(run(source), Ok(Some(Value::boolean(false))));
-}

dust-lang/tests/variables.rs

@@ -1,63 +0,0 @@
-use dust_lang::*;
-
-#[test]
-fn define_local() {
-    let source = "let x = 42;";
-
-    assert_eq!(
-        compile(source),
-        Ok(Chunk::with_data(
-            None,
-            vec![
-                (Instruction::load_constant(0, 0, false), Span(8, 10)),
-                (Instruction::define_local(0, 0, false), Span(4, 5)),
-                (Instruction::r#return(false), Span(11, 11))
-            ],
-            vec![Value::integer(42), Value::string("x")],
-            vec![Local::new(1, None, false, Scope::default(), 0)]
-        )),
-    );
-
-    assert_eq!(run(source), Ok(None));
-}
-
-#[test]
-fn let_statement_expects_identifier() {
-    let source = "let 1 = 2";
-
-    assert_eq!(
-        compile(source),
-        Err(DustError::Compile {
-            error: CompileError::ExpectedToken {
-                expected: TokenKind::Identifier,
-                found: Token::Integer("1").to_owned(),
-                position: Span(4, 5)
-            },
-            source
-        })
-    );
-}
-
-#[test]
-fn set_local() {
-    let source = "let mut x = 41; x = 42; x";
-
-    assert_eq!(
-        compile(source),
-        Ok(Chunk::with_data(
-            None,
-            vec![
-                (Instruction::load_constant(0, 0, false), Span(12, 14)),
-                (Instruction::define_local(0, 0, true), Span(8, 9)),
-                (Instruction::load_constant(1, 2, false), Span(20, 22)),
-                (Instruction::set_local(1, 0), Span(16, 17)),
-                (Instruction::get_local(2, 0), Span(24, 25)),
-                (Instruction::r#return(true), Span(25, 25)),
-            ],
-            vec![Value::integer(41), Value::string("x"), Value::integer(42)],
-            vec![Local::new(1, None, true, Scope::default(), 0)]
-        )),
-    );
-
-    assert_eq!(run(source), Ok(Some(Value::integer(42))));
-}

dust-shell/Cargo.toml

@@ -1,15 +0,0 @@
-[package]
-name = "dust-shell"
-version = "0.1.0"
-authors.workspace = true
-edition.workspace = true
-license.workspace = true
-readme.workspace = true
-repository.workspace = true
-
-[dependencies]
-clap = { version = "4.5.14", features = ["derive"] }
-colored = "2.1.0"
-dust-lang = { path = "../dust-lang" }
-env_logger = "0.11.5"
-log = "0.4.22"

dust-shell/src/main.rs

@@ -1,138 +0,0 @@
-use std::{fs::read_to_string, io::Write};
-
-use clap::Parser;
-use colored::Colorize;
-use dust_lang::{compile, format, run};
-use log::{Level, LevelFilter};
-
-#[derive(Parser)]
-struct Cli {
-    /// Source code sent via command line
-    #[arg(short, long)]
-    command: Option<String>,
-
-    /// Whether to output formatted source code
-    #[arg(short, long)]
-    format: bool,
-
-    /// Whether to output line numbers in formatted source code
-    #[arg(long)]
-    format_line_numbers: Option<bool>,
-
-    /// Whether to output colors in formatted source code
-    #[arg(long)]
-    format_colored: Option<bool>,
-
-    /// Whether to output the disassembled chunk
-    #[arg(short, long)]
-    parse: bool,
-
-    /// Whether to style the disassembled chunk
-    #[arg(long)]
-    style_disassembly: Option<bool>,
-
-    /// Log level
-    #[arg(short, long)]
-    log: Option<LevelFilter>,
-
-    /// Path to a source code file
-    path: Option<String>,
-}
-
-fn main() {
-    let args = Cli::parse();
-    let mut logger = env_logger::builder();
-
-    logger.format(|buf, record| {
-        let level_display = match record.level() {
-            Level::Info => "INFO".bold().white(),
-            Level::Debug => "DEBUG".bold().blue(),
-            Level::Warn => "WARN".bold().yellow(),
-            Level::Error => "ERROR".bold().red(),
-            Level::Trace => "TRACE".bold().purple(),
-        };
-        let module = record
-            .module_path()
-            .map(|path| path.split("::").last().unwrap_or(path))
-            .unwrap_or("unknown")
-            .dimmed();
-        let display = format!("{level_display:5} {module:^6} {args}", args = record.args());
-
-        writeln!(buf, "{display}")
-    });
-
-    if let Some(level) = args.log {
-        logger.filter_level(level).init();
-    } else {
-        logger.parse_env("DUST_LOG").init();
-    }
-
-    let source = if let Some(path) = &args.path {
-        &read_to_string(path).expect("Failed to read file")
-    } else if let Some(command) = &args.command {
-        command
-    } else {
-        eprintln!("No input provided");
-
-        return;
-    };
-
-    if args.format {
-        let line_numbers = args.format_line_numbers.unwrap_or(true);
-        let colored = args.format_colored.unwrap_or(true);
-
-        log::info!("Formatting source");
-
-        match format(source, line_numbers, colored) {
-            Ok(formatted) => println!("{}", formatted),
-            Err(error) => {
-                eprintln!("{}", error.report());
-            }
-        }
-    }
-
-    if args.parse {
-        let styled = args.style_disassembly.unwrap_or(true);
-
-        log::info!("Parsing source");
-
-        match compile(source) {
-            Ok(chunk) => {
-                let disassembly = chunk
-                    .disassembler()
-                    .source(source)
-                    .styled(styled)
-                    .disassemble();
-
-                println!("{}", disassembly);
-            }
-            Err(error) => {
-                eprintln!("{}", error.report());
-            }
-        }
-    }
-
-    if args.format || args.parse {
-        return;
-    }
-
-    match run(source) {
-        Ok(Some(value)) => println!("{}", value),
-        Ok(None) => {}
-        Err(error) => {
-            eprintln!("{}", error.report());
-        }
-    }
-}
-
-#[cfg(test)]
-mod tests {
-    use clap::CommandFactory;
-
-    use super::*;
-
-    #[test]
-    fn verify_cli() {
-        Cli::command().debug_assert();
-    }
-}

examples/assets/count.js

@@ -1,5 +0,0 @@
-var i = 0;
-
-while (i < 10000) {
-  i++;
-}

examples/assets/data.json

@@ -1,6 +0,0 @@
-[
-    { "name": "Sammy", "type": "shark", "clams": 5 },
-    { "name": "Bubbles", "type": "orca", "clams": 3 },
-    { "name": "Splish", "type": "dolphin", "clams": 2 },
-    { "name": "Splash", "type": "dolphin", "clams": 2 }
-]

examples/assets/fibonacci.js

@@ -1,11 +0,0 @@
-function fib(n) {
-  if (n <= 0) {
-    return 0;
-  } else if (n === 1) {
-    return 1;
-  } else {
-    return fib(n - 1) + fib(n - 2);
-  }
-}
-
-console.log(fib(25));

examples/async.ds

@@ -0,0 +1,19 @@
+create_random_numbers = (count <int>) <none> {
+	numbers = []
+
+	while length(numbers) < count {
+		numbers += random:integer()
+	}
+
+	output("Made " + length(numbers) + " numbers.")
+}
+
+output("This will print first.")
+
+async {
+	create_random_numbers(1000)
+ 	create_random_numbers(100)
+	create_random_numbers(10)
+}
+
+output("This will print last.")

examples/async_commands.ds

@@ -0,0 +1,17 @@
+async {
+	{
+		^echo 'Starting 1...'
+		^sleep 1
+		^echo 'Finished 1.'
+	}
+	{
+		^echo 'Starting 2...'
+		^sleep 2
+		^echo 'Finished 2.'
+	}
+	{
+		^echo 'Starting 3...'
+		^sleep 3
+		^echo 'Finished 3.'
+	}
+}

examples/async_count.ds

@@ -1,21 +0,0 @@
-count_slowly = fn (
-	multiplier: int,
-) {
-	i = 0
-
-	while i < 10 {
-		sleep_time = i * multiplier;
-
-		thread.sleep(sleep_time)
-		thread.write_line(i as str)
-
-		i += 1
-	}
-}
-
-async {
-	count_slowly(50)
-	count_slowly(100)
-	count_slowly(200)
-	count_slowly(250)
-}

examples/async_download.ds

@@ -0,0 +1,20 @@
+cast_len = 0
+characters_len = 0
+episodes_len = 0
+
+async {	
+	{
+		cast = download("https://api.sampleapis.com/futurama/cast")
+		cast_len = length(from_json(cast))		
+	}
+	{
+		characters = download("https://api.sampleapis.com/futurama/characters")	
+		characters_len = length(from_json(characters))
+	}
+	{
+		episodes = download("https://api.sampleapis.com/futurama/episodes")
+		episodes_len = length(from_json(episodes))
+	}
+}
+
+output ([cast_len, characters_len, episodes_len])

examples/clue_solver.ds

@@ -0,0 +1,53 @@
+cards = {
+	rooms = ['Library' 'Kitchen' 'Conservatory']
+	suspects = ['White' 'Green' 'Scarlett']
+	weapons = ['Rope' 'Lead_Pipe' 'Knife']
+}
+
+is_ready_to_solve = (cards <map>) <bool> {
+	(length(cards:suspects) == 1)
+	&& (length(cards:rooms) == 1)
+	&& (length(cards:weapons) == 1)
+}
+
+remove_card = (cards <map>, opponent_card <str>) <none> {
+	cards:rooms -= opponent_card
+	cards:suspects -= opponent_card
+	cards:weapons -= opponent_card
+}
+
+make_guess = (cards <map>, current_room <str>) <none> {
+	if is_ready_to_solve(cards) {
+		output(
+			'I accuse '
+			+ cards:suspects:0
+			+ ' in the ' 
+			+ cards:rooms:0  
+			+ ' with the ' 
+			+ cards:weapons:0 
+			+ '!'
+		)
+	} else {
+		output(
+			'I question '
+			+ random:from(cards:suspects)
+			+ ' in the '
+			+ current_room
+			+ ' with the '
+			+ random:from(cards:weapons)
+			+ '.'
+		)
+	}
+}
+
+take_turn = (cards <map>, opponent_card <str>, current_room <str>) <none> {
+	remove_card(cards opponent_card)
+	make_guess(cards current_room)
+}
+
+take_turn(cards 'Rope' 'Kitchen')
+take_turn(cards 'Library' 'Kitchen')
+take_turn(cards 'Conservatory' 'Kitchen')
+take_turn(cards 'White' 'Kitchen')
+take_turn(cards 'Green' 'Kitchen')
+take_turn(cards 'Knife' 'Kitchen')

examples/count.ds

@@ -1,5 +0,0 @@
-let mut i = 0;
-
-while i < 10000 {
-    i += 1;
-}

examples/download.ds

@@ -0,0 +1,10 @@
+raw_data = download("https://api.sampleapis.com/futurama/cast")
+cast_data = from_json(raw_data)
+
+names = []
+
+for cast_member in cast_data {
+	names += cast_member:name
+}
+
+assert_equal("Billy West", names:0)

examples/fibonacci.ds

@@ -1,8 +1,9 @@
-fn fib (n: int) -> int {
+fib = (i <int>) <int> {
-    if n <= 0 { return 0 }
+	if i <= 1 {
-    if n == 1 { return 1 }
+		1
-
+	} else {
-    fib(n - 1) + fib(n - 2)
+		fib(i - 1) + fib(i - 2)
+	}
 }
 
-write_line(fib(25))
+fib(8)

examples/fizzbuzz.ds

@@ -1,20 +1,18 @@
-let mut count = 1
+count = 1
 
 while count <= 15 {
-	let divides_by_3 = count % 3 == 0
+	divides_by_3 = count % 3 == 0
-	let divides_by_5 = count % 5 == 0
+	divides_by_5 = count % 5 == 0
 
-	let output = if divides_by_3 && divides_by_5 {
+	if divides_by_3 && divides_by_5 { 
-		"fizzbuzz"
+		output('fizzbuzz')
-	} else if divides_by_3 {
+	} else if divides_by_3 { 
-		"fizz"
+		output('fizz')
 	} else if divides_by_5 {
-		"buzz"
+		output('buzz')
-	} else {
+	} else { 
-		to_string(count)
+		output(count)
 	}
-
+	
-	write_line(output)
-
 	count += 1
 }

examples/guessing_game.ds

@@ -1,19 +1,26 @@
-write_line("Guess the number.")
+# This is a Dust version of an example from the Rust Book.
+#
+# https://doc.rust-lang.org/book/ch02-00-guessing-game-tutorial.html
 
-let secret_number = random(0..100);
+output("Guess the number.")
+
+secret_number = int:random_range(0..=100);
 
 loop {
-	write_line("Input your guess.")
+	output("Please input your guess.")
 
-	let input = io.read_line();
+	input = io:stdin():expect("Failed to read line.")
-	let guess = int.parse(input);
+	guess = int:parse(input);
 
-	if guess < secret_number {
+	output("You guessed: " + guess)
-		io.write_line("Too low!")
+
-	} else if guess > secret_number {
+	match cmp(guess, secret_number) {
-		io.write_line("Too high!")
+		Ordering::Less -> output("Too small!"),
-	} else {
+		Ordering::Greater -> output("Too big!"),
-		io.write_line("You win!")
+		Ordering::Equal -> {
-		break
+			output("You win!");
+			break;
+		}
 	}
 }
+

examples/hello_world.ds

@@ -1,6 +1 @@
-write_line("Hello, world!")
+output('Hello, world!')
-write_line("Enter your name...")
-
-let name = read_line()
-
-write_line("Hello " + name + "!")

examples/jq_data.ds

@@ -0,0 +1,12 @@
+data = json:parse(fs:read_file('examples/assets/jq_data.json'))
+
+new_data = []
+
+for commit_data in data as collection {	
+	new_data += {
+		message = commit_data:commit:message
+		name = commit_data:commit:committer:name
+	}
+}
+
+new_data

examples/json_length.ds

@@ -1,4 +0,0 @@
-input = fs.read_file('examples/assets/data.json')
-data = json.parse(input)
-
-length(data)

examples/random.ds

@@ -0,0 +1,13 @@
+stuff = [
+	random:integer()
+	random:integer()
+	random:integer()
+	random:float()
+	random:float()
+	random:float()
+	random:boolean()
+	random:boolean()
+	random:boolean()
+]
+
+random:from(stuff)

examples/sea_creatures.ds

@@ -0,0 +1,19 @@
+raw_data = fs:read_file('examples/assets/seaCreatures.json')
+sea_creatures = json:parse(raw_data)
+
+data = {
+	creatures = []
+	total_clams = 0
+	dolphin_clams = 0
+}
+
+for creature in sea_creatures {
+	data:creatures += creature:name
+	data:total_clams += creature:clams
+
+	if creature:type == 'dolphin' {
+		data:dolphin_clams += creature:clams
+	}
+}
+
+data

examples/type_inference.ds

@@ -1,20 +0,0 @@
-// This function returns its argument.
-foo = fn <T>(x: T) -> T { x }
-
-// Use turbofish to supply type information.
-bar = foo::<str>("hi")
-
-// Use type annotation
-baz: str = foo("hi")
-
-// The `json.parse` function takes a string and returns the specified type
-
-// Use turbofish
-x = json.parse::<int>("1")
-
-// Use type annotation
-x: int = json.parse("1")
-
-x: int = {
-	json.parse("1")
-}

scripts/bench.fish

@@ -0,0 +1,35 @@
+#!/usr/bin/fish
+# This script is has the following prerequisites (aside from fish):
+# - hyperfine
+# - dust (can be installed with "cargo install dust-lang")
+# - jq
+# - nodejs
+# - nushell
+# - dielectron.json (can be downloaded from https://opendata.cern.ch/record/304)
+
+hyperfine \
+      --shell none \
+      --parameter-list data_path examples/assets/seaCreatures.json \
+      --warmup 3 \
+      "dust -c 'length(json:parse(input))' -p {data_path}" \
+      "jq 'length' {data_path}" \
+      "node --eval \"require('node:fs').readFile('{data_path}', (err, data)=>{console.log(JSON.parse(data).length)})\"" \
+      "nu -c 'open {data_path} | length'"
+
+hyperfine \
+      --shell none \
+      --parameter-list data_path examples/assets/jq_data.json \
+      --warmup 3 \
+      "dust -c 'length(json:parse(input))' -p {data_path}" \
+      "jq 'length' {data_path}" \
+      "node --eval \"require('node:fs').readFile('{data_path}', (err, data)=>{console.log(JSON.parse(data).length)})\"" \
+      "nu -c 'open {data_path} | length'"
+
+hyperfine \
+      --shell none \
+      --parameter-list data_path dielectron.json \
+      --warmup 3 \
+      "dust -c 'length(json:parse(input))' -p {data_path}" \
+      "jq 'length' {data_path}" \
+      "node --eval \"require('node:fs').readFile('{data_path}', (err, data)=>{console.log(JSON.parse(data).length)})\"" \
+      "nu -c 'open {data_path} | length'"

scripts/build_debug.fish

@@ -0,0 +1,8 @@
+#!/usr/bin/fish
+# Build the project in debug mode.
+
+cd tree-sitter-dust/
+tree-sitter generate --debug-build --no-bindings
+
+cd ..
+cargo build

scripts/build_release.fish

@@ -0,0 +1,8 @@
+#!/bin/fish
+# Build the project in release mode.
+
+cd tree-sitter-dust/
+tree-sitter generate --no-bindings
+
+cd ..
+cargo build --release

scripts/test.fish

@@ -0,0 +1,9 @@
+#!/usr/bin/fish
+# Build the project in debug mode.
+
+cd tree-sitter-dust/
+tree-sitter generate --debug-build --no-bindings
+tree-sitter test
+
+cd ..
+cargo test

src/abstract_tree/as.rs

@@ -0,0 +1,131 @@
+use serde::{Deserialize, Serialize};
+use tree_sitter::Node;
+
+use crate::{
+    error::{RuntimeError, SyntaxError, ValidationError},
+    AbstractTree, Context, Expression, Format, List, SourcePosition, Type, Value,
+};
+
+#[derive(Debug, Clone, Serialize, Deserialize, Eq, PartialEq, PartialOrd, Ord)]
+pub struct As {
+    expression: Expression,
+    r#type: Type,
+    position: SourcePosition,
+}
+
+impl AbstractTree for As {
+    fn from_syntax(node: Node, source: &str, context: &Context) -> Result<Self, SyntaxError> {
+        SyntaxError::expect_syntax_node("as", node)?;
+
+        let expression_node = node.child(0).unwrap();
+        let expression = Expression::from_syntax(expression_node, source, context)?;
+
+        let type_node = node.child(2).unwrap();
+        let r#type = Type::from_syntax(type_node, source, context)?;
+
+        Ok(As {
+            expression,
+            r#type,
+            position: SourcePosition::from(node.range()),
+        })
+    }
+
+    fn expected_type(&self, _context: &Context) -> Result<Type, ValidationError> {
+        Ok(self.r#type.clone())
+    }
+
+    fn validate(&self, _source: &str, context: &Context) -> Result<(), ValidationError> {
+        let initial_type = self.expression.expected_type(context)?;
+
+        if self.r#type.accepts(&initial_type) {
+            return Ok(());
+        }
+
+        if let Type::ListOf(item_type) = &self.r#type {
+            match &initial_type {
+                Type::ListOf(expected_item_type) => {
+                    println!("{item_type} {expected_item_type}");
+
+                    if !item_type.accepts(&expected_item_type) {
+                        return Err(ValidationError::TypeCheck {
+                            expected: self.r#type.clone(),
+                            actual: initial_type.clone(),
+                            position: self.position,
+                        });
+                    }
+                }
+                Type::String => {
+                    if let Type::String = item_type.as_ref() {
+                    } else {
+                        return Err(ValidationError::ConversionImpossible {
+                            initial_type,
+                            target_type: self.r#type.clone(),
+                        });
+                    }
+                }
+
+                Type::Any => {
+                    // Do no validation when converting from "any" to a list.
+                    // This effectively defers to runtime behavior, potentially
+                    // causing a runtime error.
+                }
+                _ => {
+                    return Err(ValidationError::ConversionImpossible {
+                        initial_type,
+                        target_type: self.r#type.clone(),
+                    })
+                }
+            }
+        }
+
+        Ok(())
+    }
+
+    fn run(&self, source: &str, context: &Context) -> Result<Value, RuntimeError> {
+        let value = self.expression.run(source, context)?;
+        let converted_value = if self.r#type.accepts(&value.r#type()?) {
+            return Ok(value);
+        } else if let Type::ListOf(_) = self.r#type {
+            match value {
+                Value::List(list) => Value::List(list),
+                Value::String(string) => {
+                    let chars = string
+                        .chars()
+                        .map(|char| Value::String(char.to_string()))
+                        .collect();
+
+                    Value::List(List::with_items(chars))
+                }
+                _ => {
+                    return Err(RuntimeError::ConversionImpossible {
+                        from: value.r#type()?,
+                        to: self.r#type.clone(),
+                        position: self.position.clone(),
+                    });
+                }
+            }
+        } else if let Type::Integer = self.r#type {
+            match value {
+                Value::Integer(integer) => Value::Integer(integer),
+                Value::Float(float) => Value::Integer(float as i64),
+                _ => {
+                    return Err(RuntimeError::ConversionImpossible {
+                        from: value.r#type()?,
+                        to: self.r#type.clone(),
+                        position: self.position.clone(),
+                    })
+                }
+            }
+        } else {
+            todo!()
+        };
+
+        Ok(converted_value)
+    }
+}
+
+impl Format for As {
+    fn format(&self, _output: &mut String, _indent_level: u8) {
+        todo!()
+    }
+}

src/abstract_tree/assignment.rs

@@ -0,0 +1,186 @@
+use serde::{Deserialize, Serialize};
+
+use crate::{
+    context::Context,
+    error::{RuntimeError, SyntaxError, ValidationError},
+    AbstractTree, AssignmentOperator, Format, Function, Identifier, SourcePosition, Statement,
+    SyntaxNode, Type, TypeSpecification, Value,
+};
+
+/// Variable assignment, including add-assign and subtract-assign operations.
+#[derive(Debug, Clone, Serialize, Deserialize, Eq, PartialEq, PartialOrd, Ord)]
+pub struct Assignment {
+    identifier: Identifier,
+    type_specification: Option<TypeSpecification>,
+    operator: AssignmentOperator,
+    statement: Statement,
+    syntax_position: SourcePosition,
+}
+
+impl AbstractTree for Assignment {
+    fn from_syntax(
+        syntax_node: SyntaxNode,
+        source: &str,
+        context: &Context,
+    ) -> Result<Self, SyntaxError> {
+        SyntaxError::expect_syntax_node("assignment", syntax_node)?;
+
+        let child_count = syntax_node.child_count();
+
+        let identifier_node = syntax_node.child(0).unwrap();
+        let identifier = Identifier::from_syntax(identifier_node, source, context)?;
+
+        let type_node = syntax_node.child(1).unwrap();
+        let type_specification = if type_node.kind() == "type_specification" {
+            Some(TypeSpecification::from_syntax(type_node, source, context)?)
+        } else {
+            None
+        };
+
+        let operator_node = syntax_node.child(child_count - 2).unwrap();
+        let operator = AssignmentOperator::from_syntax(operator_node, source, context)?;
+
+        let statement_node = syntax_node.child(child_count - 1).unwrap();
+        let statement = Statement::from_syntax(statement_node, source, context)?;
+
+        Ok(Assignment {
+            identifier,
+            type_specification,
+            operator,
+            statement,
+            syntax_position: syntax_node.range().into(),
+        })
+    }
+
+    fn validate(&self, source: &str, context: &Context) -> Result<(), ValidationError> {
+        if let AssignmentOperator::Equal = self.operator {
+            let r#type = if let Some(definition) = &self.type_specification {
+                definition.inner().clone()
+            } else {
+                self.statement.expected_type(context)?
+            };
+
+            log::info!("Setting type: {} <{}>", self.identifier, r#type);
+
+            context.set_type(self.identifier.clone(), r#type)?;
+        }
+
+        if let Some(type_specification) = &self.type_specification {
+            match self.operator {
+                AssignmentOperator::Equal => {
+                    let expected = type_specification.inner();
+                    let actual = self.statement.expected_type(context)?;
+
+                    if !expected.accepts(&actual) {
+                        return Err(ValidationError::TypeCheck {
+                            expected: expected.clone(),
+                            actual,
+                            position: self.syntax_position,
+                        });
+                    }
+                }
+                AssignmentOperator::PlusEqual => {
+                    if let Type::ListOf(expected) = type_specification.inner() {
+                        let actual = self.identifier.expected_type(context)?;
+
+                        if !expected.accepts(&actual) {
+                            return Err(ValidationError::TypeCheck {
+                                expected: expected.as_ref().clone(),
+                                actual,
+                                position: self.syntax_position,
+                            });
+                        }
+                    } else {
+                        let expected = type_specification.inner();
+                        let actual = self.identifier.expected_type(context)?;
+
+                        if !expected.accepts(&actual) {
+                            return Err(ValidationError::TypeCheck {
+                                expected: expected.clone(),
+                                actual,
+                                position: self.syntax_position,
+                            });
+                        }
+                    }
+                }
+                AssignmentOperator::MinusEqual => todo!(),
+            }
+        } else {
+            match self.operator {
+                AssignmentOperator::Equal => {}
+                AssignmentOperator::PlusEqual => {
+                    if let Type::ListOf(expected) = self.identifier.expected_type(context)? {
+                        let actual = self.statement.expected_type(context)?;
+
+                        if !expected.accepts(&actual) {
+                            return Err(ValidationError::TypeCheck {
+                                expected: expected.as_ref().clone(),
+                                actual,
+                                position: self.syntax_position,
+                            });
+                        }
+                    }
+                }
+                AssignmentOperator::MinusEqual => todo!(),
+            }
+        }
+
+        self.statement.validate(source, context)?;
+
+        Ok(())
+    }
+
+    fn run(&self, source: &str, context: &Context) -> Result<Value, RuntimeError> {
+        let right = self.statement.run(source, context)?;
+
+        let new_value = match self.operator {
+            AssignmentOperator::PlusEqual => {
+                let left = self.identifier.run(source, context)?;
+
+                left.add(right, self.syntax_position)?
+            }
+            AssignmentOperator::MinusEqual => {
+                if let Some(left) = context.get_value(&self.identifier)? {
+                    left.subtract(right, self.syntax_position)?
+                } else {
+                    return Err(RuntimeError::ValidationFailure(
+                        ValidationError::VariableIdentifierNotFound(self.identifier.clone()),
+                    ));
+                }
+            }
+            AssignmentOperator::Equal => right,
+        };
+
+        if let Value::Function(Function::ContextDefined(function_node)) = &new_value {
+            function_node
+                .context()
+                .set_value(self.identifier.clone(), new_value.clone())?;
+        }
+
+        log::info!("RUN assignment: {} = {}", self.identifier, new_value);
+
+        context.set_value(self.identifier.clone(), new_value)?;
+
+        Ok(Value::none())
+    }
+
+    fn expected_type(&self, _context: &Context) -> Result<Type, ValidationError> {
+        Ok(Type::None)
+    }
+}
+
+impl Format for Assignment {
+    fn format(&self, output: &mut String, indent_level: u8) {
+        self.identifier.format(output, indent_level);
+
+        if let Some(type_specification) = &self.type_specification {
+            type_specification.format(output, indent_level);
+        }
+
+        output.push(' ');
+        self.operator.format(output, indent_level);
+        output.push(' ');
+
+        self.statement.format(output, 0);
+    }
+}

src/abstract_tree/assignment_operator.rs

@@ -0,0 +1,62 @@
+use serde::{Deserialize, Serialize};
+
+use crate::{
+    error::{RuntimeError, SyntaxError, ValidationError},
+    AbstractTree, Context, Format, SyntaxNode, Type, Value,
+};
+
+/// Operators that be used in an assignment statement.
+#[derive(Debug, Clone, Serialize, Deserialize, Eq, PartialEq, PartialOrd, Ord)]
+pub enum AssignmentOperator {
+    Equal,
+    PlusEqual,
+    MinusEqual,
+}
+
+impl AbstractTree for AssignmentOperator {
+    fn from_syntax(
+        node: SyntaxNode,
+        _source: &str,
+        _context: &Context,
+    ) -> Result<Self, SyntaxError> {
+        SyntaxError::expect_syntax_node("assignment_operator", node)?;
+
+        let operator_node = node.child(0).unwrap();
+        let operator = match operator_node.kind() {
+            "=" => AssignmentOperator::Equal,
+            "+=" => AssignmentOperator::PlusEqual,
+            "-=" => AssignmentOperator::MinusEqual,
+            _ => {
+                return Err(SyntaxError::UnexpectedSyntaxNode {
+                    expected: "=, += or -=".to_string(),
+                    actual: operator_node.kind().to_string(),
+                    position: node.range().into(),
+                })
+            }
+        };
+
+        Ok(operator)
+    }
+
+    fn run(&self, _source: &str, _context: &Context) -> Result<Value, RuntimeError> {
+        Ok(Value::none())
+    }
+
+    fn expected_type(&self, _context: &Context) -> Result<Type, ValidationError> {
+        Ok(Type::None)
+    }
+
+    fn validate(&self, _source: &str, _context: &Context) -> Result<(), ValidationError> {
+        Ok(())
+    }
+}
+
+impl Format for AssignmentOperator {
+    fn format(&self, output: &mut String, _indent_level: u8) {
+        match self {
+            AssignmentOperator::Equal => output.push('='),
+            AssignmentOperator::PlusEqual => output.push_str("+="),
+            AssignmentOperator::MinusEqual => output.push_str("-="),
+        }
+    }
+}

src/abstract_tree/block.rs

@@ -0,0 +1,170 @@
+use std::{
+    fmt::{self, Formatter},
+    sync::RwLock,
+};
+
+use rayon::prelude::*;
+use serde::{Deserialize, Serialize};
+
+use crate::{
+    error::{rw_lock_error::RwLockError, RuntimeError, SyntaxError, ValidationError},
+    AbstractTree, Context, Format, Statement, SyntaxNode, Type, Value,
+};
+
+/// Abstract representation of a block.
+///
+/// A block is almost identical to the root except that it must have curly
+/// braces and can optionally be asynchronous. A block evaluates to the value of
+/// its final statement but an async block will short-circuit if a statement
+/// results in an error. Note that this will be the first statement to encounter
+/// an error at runtime, not necessarilly the first statement as they are
+/// written.
+#[derive(Clone, Serialize, Deserialize, Eq, PartialEq, PartialOrd, Ord)]
+pub struct Block {
+    is_async: bool,
+    contains_return: bool,
+    statements: Vec<Statement>,
+}
+
+impl Block {
+    pub fn contains_return(&self) -> bool {
+        self.contains_return
+    }
+}
+
+impl AbstractTree for Block {
+    fn from_syntax(node: SyntaxNode, source: &str, context: &Context) -> Result<Self, SyntaxError> {
+        SyntaxError::expect_syntax_node("block", node)?;
+
+        let first_child = node.child(0).unwrap();
+        let is_async = first_child.kind() == "async";
+        let mut contains_return = false;
+
+        let statement_count = if is_async {
+            node.child_count() - 3
+        } else {
+            node.child_count() - 2
+        };
+        let mut statements = Vec::with_capacity(statement_count);
+        let block_context = Context::with_variables_from(context)?;
+
+        for index in 1..node.child_count() - 1 {
+            let child_node = node.child(index).unwrap();
+
+            if child_node.kind() == "statement" {
+                let statement = Statement::from_syntax(child_node, source, &block_context)?;
+
+                if statement.is_return() {
+                    contains_return = true;
+                }
+
+                statements.push(statement);
+            }
+        }
+
+        Ok(Block {
+            is_async,
+            contains_return,
+            statements,
+        })
+    }
+
+    fn validate(&self, _source: &str, _context: &Context) -> Result<(), ValidationError> {
+        for statement in &self.statements {
+            statement.validate(_source, _context)?;
+        }
+
+        Ok(())
+    }
+
+    fn run(&self, _source: &str, _context: &Context) -> Result<Value, RuntimeError> {
+        if self.is_async {
+            let statements = &self.statements;
+            let final_result = RwLock::new(Ok(Value::none()));
+
+            statements
+                .into_par_iter()
+                .enumerate()
+                .find_map_first(|(index, statement)| {
+                    let result = statement.run(_source, _context);
+                    let should_return = if self.contains_return {
+                        statement.is_return()
+                    } else {
+                        index == statements.len() - 1
+                    };
+
+                    if should_return {
+                        let get_write_lock = final_result.write();
+
+                        match get_write_lock {
+                            Ok(mut final_result) => {
+                                *final_result = result;
+                                None
+                            }
+                            Err(_error) => Some(Err(RuntimeError::RwLock(RwLockError))),
+                        }
+                    } else {
+                        None
+                    }
+                })
+                .unwrap_or(final_result.into_inner().map_err(|_| RwLockError)?)
+        } else {
+            for (index, statement) in self.statements.iter().enumerate() {
+                if statement.is_return() {
+                    return statement.run(_source, _context);
+                }
+
+                if index == self.statements.len() - 1 {
+                    return statement.run(_source, _context);
+                }
+            }
+
+            Ok(Value::none())
+        }
+    }
+
+    fn expected_type(&self, _context: &Context) -> Result<Type, ValidationError> {
+        for (index, statement) in self.statements.iter().enumerate() {
+            if statement.is_return() {
+                return statement.expected_type(_context);
+            }
+
+            if index == self.statements.len() - 1 {
+                return statement.expected_type(_context);
+            }
+        }
+
+        Ok(Type::None)
+    }
+}
+
+impl Format for Block {
+    fn format(&self, output: &mut String, indent_level: u8) {
+        if self.is_async {
+            output.push_str("async {\n");
+        } else {
+            output.push_str("{\n");
+        }
+
+        for (index, statement) in self.statements.iter().enumerate() {
+            if index > 0 {
+                output.push('\n');
+            }
+
+            statement.format(output, indent_level + 1);
+        }
+
+        output.push('\n');
+        Block::indent(output, indent_level);
+        output.push('}');
+    }
+}
+
+impl fmt::Debug for Block {
+    fn fmt(&self, f: &mut Formatter) -> fmt::Result {
+        f.debug_struct("Block")
+            .field("is_async", &self.is_async)
+            .field("statements", &self.statements)
+            .finish()
+    }
+}

src/abstract_tree/command.rs

@@ -0,0 +1,76 @@
+use std::process::{self, Stdio};
+
+use serde::{Deserialize, Serialize};
+use tree_sitter::Node as SyntaxNode;
+
+use crate::{
+    error::{RuntimeError, SyntaxError, ValidationError},
+    AbstractTree, Context, Format, Type, Value,
+};
+
+/// An external program invokation.
+#[derive(Debug, Clone, Serialize, Deserialize, Eq, PartialEq, PartialOrd, Ord)]
+pub struct Command {
+    command_text: String,
+    command_arguments: Vec<String>,
+}
+
+impl AbstractTree for Command {
+    fn from_syntax(
+        node: SyntaxNode,
+        source: &str,
+        _context: &Context,
+    ) -> Result<Self, SyntaxError> {
+        SyntaxError::expect_syntax_node("command", node)?;
+
+        let command_text_node = node.child(1).unwrap();
+        let command_text = source[command_text_node.byte_range()].to_string();
+
+        let mut command_arguments = Vec::new();
+
+        for index in 2..node.child_count() {
+            let text_node = node.child(index).unwrap();
+            let mut text = source[text_node.byte_range()].to_string();
+
+            if (text.starts_with('\'') && text.ends_with('\''))
+                || (text.starts_with('"') && text.ends_with('"'))
+                || (text.starts_with('`') && text.ends_with('`'))
+            {
+                text = text[1..text.len() - 1].to_string();
+            }
+
+            command_arguments.push(text);
+        }
+
+        Ok(Command {
+            command_text,
+            command_arguments,
+        })
+    }
+
+    fn expected_type(&self, _context: &Context) -> Result<Type, ValidationError> {
+        Ok(Type::String)
+    }
+
+    fn validate(&self, _source: &str, _context: &Context) -> Result<(), ValidationError> {
+        Ok(())
+    }
+
+    fn run(&self, _source: &str, _context: &Context) -> Result<Value, RuntimeError> {
+        let output = process::Command::new(&self.command_text)
+            .args(&self.command_arguments)
+            .stdout(Stdio::piped())
+            .stderr(Stdio::inherit())
+            .spawn()?
+            .wait_with_output()?
+            .stdout;
+
+        Ok(Value::String(String::from_utf8(output)?))
+    }
+}
+
+impl Format for Command {
+    fn format(&self, _output: &mut String, _indent_level: u8) {
+        todo!()
+    }
+}

src/abstract_tree/enum_defintion.rs

@@ -0,0 +1,92 @@
+use serde::{Deserialize, Serialize};
+use tree_sitter::Node as SyntaxNode;
+
+use crate::{
+    error::{RuntimeError, SyntaxError, ValidationError},
+    AbstractTree, Context, EnumInstance, Format, Identifier, Type, TypeDefinition, Value,
+};
+
+#[derive(Debug, Clone, Serialize, Deserialize, Eq, PartialEq, PartialOrd, Ord)]
+pub struct EnumDefinition {
+    identifier: Identifier,
+    variants: Vec<(Identifier, Vec<Type>)>,
+}
+
+impl EnumDefinition {
+    pub fn new(identifier: Identifier, variants: Vec<(Identifier, Vec<Type>)>) -> Self {
+        Self {
+            identifier,
+            variants,
+        }
+    }
+
+    pub fn instantiate(&self, variant: Identifier, content: Option<Value>) -> EnumInstance {
+        EnumInstance::new(self.identifier.clone(), variant, content)
+    }
+
+    pub fn identifier(&self) -> &Identifier {
+        &self.identifier
+    }
+
+    pub fn variants(&self) -> &Vec<(Identifier, Vec<Type>)> {
+        &self.variants
+    }
+}
+
+impl AbstractTree for EnumDefinition {
+    fn from_syntax(node: SyntaxNode, source: &str, context: &Context) -> Result<Self, SyntaxError> {
+        SyntaxError::expect_syntax_node("enum_definition", node)?;
+
+        let identifier_node = node.child(1).unwrap();
+        let identifier = Identifier::from_syntax(identifier_node, source, context)?;
+
+        let mut variants = Vec::new();
+        let mut current_identifier: Option<Identifier> = None;
+        let mut types = Vec::new();
+
+        for index in 3..node.child_count() - 1 {
+            let child = node.child(index).unwrap();
+
+            if child.kind() == "identifier" {
+                if let Some(identifier) = &current_identifier {
+                    variants.push((identifier.clone(), types));
+                }
+
+                current_identifier = Some(Identifier::from_syntax(child, source, context)?);
+                types = Vec::new();
+            }
+
+            if child.kind() == "type" {
+                let r#type = Type::from_syntax(child, source, context)?;
+
+                types.push(r#type);
+            }
+        }
+
+        Ok(EnumDefinition {
+            identifier,
+            variants,
+        })
+    }
+
+    fn expected_type(&self, _context: &Context) -> Result<Type, ValidationError> {
+        Ok(Type::None)
+    }
+
+    fn validate(&self, _source: &str, context: &Context) -> Result<(), ValidationError> {
+        context.set_definition(self.identifier.clone(), TypeDefinition::Enum(self.clone()))?;
+        self.identifier.validate(_source, context)?;
+
+        Ok(())
+    }
+
+    fn run(&self, _source: &str, _context: &Context) -> Result<Value, RuntimeError> {
+        Ok(Value::none())
+    }
+}
+
+impl Format for EnumDefinition {
+    fn format(&self, _output: &mut String, _indent_level: u8) {
+        todo!()
+    }
+}

src/abstract_tree/enum_pattern.rs

@@ -0,0 +1,70 @@
+use serde::{Deserialize, Serialize};
+use tree_sitter::Node as SyntaxNode;
+
+use crate::{
+    error::{RuntimeError, SyntaxError, ValidationError},
+    AbstractTree, Context, Format, Identifier, Type, Value,
+};
+
+#[derive(Debug, Clone, Serialize, Deserialize, Eq, PartialEq, PartialOrd, Ord)]
+pub struct EnumPattern {
+    name: Identifier,
+    variant: Identifier,
+    inner_identifier: Option<Identifier>,
+}
+
+impl EnumPattern {
+    pub fn name(&self) -> &Identifier {
+        &self.name
+    }
+
+    pub fn variant(&self) -> &Identifier {
+        &self.variant
+    }
+
+    pub fn inner_identifier(&self) -> &Option<Identifier> {
+        &self.inner_identifier
+    }
+}
+
+impl AbstractTree for EnumPattern {
+    fn from_syntax(node: SyntaxNode, source: &str, context: &Context) -> Result<Self, SyntaxError> {
+        SyntaxError::expect_syntax_node("enum_pattern", node)?;
+
+        let enum_name_node = node.child(0).unwrap();
+        let name = Identifier::from_syntax(enum_name_node, source, context)?;
+
+        let enum_variant_node = node.child(2).unwrap();
+        let variant = Identifier::from_syntax(enum_variant_node, source, context)?;
+
+        let inner_identifier = if let Some(child) = node.child(4) {
+            Some(Identifier::from_syntax(child, source, context)?)
+        } else {
+            None
+        };
+
+        Ok(EnumPattern {
+            name,
+            variant,
+            inner_identifier,
+        })
+    }
+
+    fn expected_type(&self, _context: &Context) -> Result<Type, ValidationError> {
+        Ok(Type::None)
+    }
+
+    fn validate(&self, _source: &str, _context: &Context) -> Result<(), ValidationError> {
+        Ok(())
+    }
+
+    fn run(&self, _source: &str, _context: &Context) -> Result<Value, RuntimeError> {
+        Ok(Value::none())
+    }
+}
+
+impl Format for EnumPattern {
+    fn format(&self, _output: &mut String, _indent_level: u8) {
+        todo!()
+    }
+}

src/abstract_tree/expression.rs

@@ -0,0 +1,120 @@
+use serde::{Deserialize, Serialize};
+
+use crate::{
+    error::{RuntimeError, SyntaxError, ValidationError},
+    value_node::ValueNode,
+    AbstractTree, As, Command, Context, Format, FunctionCall, Identifier, Index, Logic, Math,
+    SyntaxNode, Type, Value,
+};
+
+/// Abstract representation of an expression statement.
+///
+/// Unlike statements, which can involve complex logic, an expression is
+/// expected to evaluate to a value. However, an expression can still contain
+/// nested statements and may evaluate to an empty value.
+#[derive(Debug, Clone, Serialize, Deserialize, Eq, PartialEq, PartialOrd, Ord)]
+pub enum Expression {
+    Value(ValueNode),
+    Identifier(Identifier),
+    Index(Box<Index>),
+    Math(Box<Math>),
+    Logic(Box<Logic>),
+    FunctionCall(Box<FunctionCall>),
+    Command(Command),
+    As(Box<As>),
+}
+
+impl AbstractTree for Expression {
+    fn from_syntax(
+        node: SyntaxNode,
+        source: &str,
+        _context: &Context,
+    ) -> Result<Self, SyntaxError> {
+        SyntaxError::expect_syntax_node("expression", node)?;
+
+        let child = if node.child(0).unwrap().is_named() {
+            node.child(0).unwrap()
+        } else {
+            node.child(1).unwrap()
+        };
+
+        let expression = match child.kind() {
+            "as" => Expression::As(Box::new(As::from_syntax(child, source, _context)?)),
+            "value" => Expression::Value(ValueNode::from_syntax(child, source, _context)?),
+            "identifier" => {
+                Expression::Identifier(Identifier::from_syntax(child, source, _context)?)
+            }
+            "index" => Expression::Index(Box::new(Index::from_syntax(child, source, _context)?)),
+            "math" => Expression::Math(Box::new(Math::from_syntax(child, source, _context)?)),
+            "logic" => Expression::Logic(Box::new(Logic::from_syntax(child, source, _context)?)),
+            "function_call" => Expression::FunctionCall(Box::new(FunctionCall::from_syntax(
+                child, source, _context,
+            )?)),
+            "command" => Expression::Command(Command::from_syntax(child, source, _context)?),
+            _ => {
+                return Err(SyntaxError::UnexpectedSyntaxNode {
+                    expected: "value, identifier, index, math, logic, function call, as or command"
+                        .to_string(),
+                    actual: child.kind().to_string(),
+                    position: node.range().into(),
+                })
+            }
+        };
+
+        Ok(expression)
+    }
+
+    fn expected_type(&self, _context: &Context) -> Result<Type, ValidationError> {
+        match self {
+            Expression::Value(value_node) => value_node.expected_type(_context),
+            Expression::Identifier(identifier) => identifier.expected_type(_context),
+            Expression::Math(math) => math.expected_type(_context),
+            Expression::Logic(logic) => logic.expected_type(_context),
+            Expression::FunctionCall(function_call) => function_call.expected_type(_context),
+            Expression::Index(index) => index.expected_type(_context),
+            Expression::Command(command) => command.expected_type(_context),
+            Expression::As(r#as) => r#as.expected_type(_context),
+        }
+    }
+
+    fn validate(&self, _source: &str, _context: &Context) -> Result<(), ValidationError> {
+        match self {
+            Expression::Value(value_node) => value_node.validate(_source, _context),
+            Expression::Identifier(identifier) => identifier.validate(_source, _context),
+            Expression::Math(math) => math.validate(_source, _context),
+            Expression::Logic(logic) => logic.validate(_source, _context),
+            Expression::FunctionCall(function_call) => function_call.validate(_source, _context),
+            Expression::Index(index) => index.validate(_source, _context),
+            Expression::Command(command) => command.validate(_source, _context),
+            Expression::As(r#as) => r#as.validate(_source, _context),
+        }
+    }
+
+    fn run(&self, _source: &str, _context: &Context) -> Result<Value, RuntimeError> {
+        match self {
+            Expression::Value(value_node) => value_node.run(_source, _context),
+            Expression::Identifier(identifier) => identifier.run(_source, _context),
+            Expression::Math(math) => math.run(_source, _context),
+            Expression::Logic(logic) => logic.run(_source, _context),
+            Expression::FunctionCall(function_call) => function_call.run(_source, _context),
+            Expression::Index(index) => index.run(_source, _context),
+            Expression::Command(command) => command.run(_source, _context),
+            Expression::As(r#as) => r#as.run(_source, _context),
+        }
+    }
+}
+
+impl Format for Expression {
+    fn format(&self, _output: &mut String, _indent_level: u8) {
+        match self {
+            Expression::Value(value_node) => value_node.format(_output, _indent_level),
+            Expression::Identifier(identifier) => identifier.format(_output, _indent_level),
+            Expression::Math(math) => math.format(_output, _indent_level),
+            Expression::Logic(logic) => logic.format(_output, _indent_level),
+            Expression::FunctionCall(function_call) => function_call.format(_output, _indent_level),
+            Expression::Index(index) => index.format(_output, _indent_level),
+            Expression::Command(command) => command.format(_output, _indent_level),
+            Expression::As(r#as) => r#as.format(_output, _indent_level),
+        }
+    }
+}

src/abstract_tree/for.rs

@@ -0,0 +1,153 @@
+use rayon::prelude::*;
+use serde::{Deserialize, Serialize};
+
+use crate::{
+    error::{RuntimeError, SyntaxError, ValidationError},
+    AbstractTree, Block, Context, Expression, Format, Identifier, SourcePosition, SyntaxNode, Type,
+    Value,
+};
+
+/// Abstract representation of a for loop statement.
+#[derive(Debug, Clone, Serialize, Deserialize, Eq, PartialEq, PartialOrd, Ord)]
+pub struct For {
+    is_async: bool,
+    item_id: Identifier,
+    collection: Expression,
+    block: Block,
+    source_position: SourcePosition,
+
+    #[serde(skip)]
+    context: Context,
+}
+
+impl AbstractTree for For {
+    fn from_syntax(node: SyntaxNode, source: &str, context: &Context) -> Result<Self, SyntaxError> {
+        SyntaxError::expect_syntax_node("for", node)?;
+
+        let for_node = node.child(0).unwrap();
+        let is_async = match for_node.kind() {
+            "for" => false,
+            "async for" => true,
+            _ => {
+                return Err(SyntaxError::UnexpectedSyntaxNode {
+                    expected: "for or async for".to_string(),
+                    actual: for_node.kind().to_string(),
+                    position: node.range().into(),
+                })
+            }
+        };
+
+        let identifier_node = node.child(1).unwrap();
+        let identifier = Identifier::from_syntax(identifier_node, source, context)?;
+
+        let expression_node = node.child(3).unwrap();
+        let expression = Expression::from_syntax(expression_node, source, context)?;
+
+        let loop_context = Context::with_variables_from(context)?;
+
+        let item_node = node.child(4).unwrap();
+        let item = Block::from_syntax(item_node, source, &loop_context)?;
+
+        Ok(For {
+            is_async,
+            item_id: identifier,
+            collection: expression,
+            block: item,
+            source_position: SourcePosition::from(node.range()),
+            context: loop_context,
+        })
+    }
+
+    fn expected_type(&self, _context: &Context) -> Result<Type, ValidationError> {
+        Ok(Type::None)
+    }
+
+    fn validate(&self, _source: &str, context: &Context) -> Result<(), ValidationError> {
+        self.collection.validate(_source, context)?;
+
+        let collection_type = self.collection.expected_type(context)?;
+        let item_type = match collection_type {
+            Type::Any => Type::Any,
+            Type::Collection => Type::Any,
+            Type::List => Type::Any,
+            Type::ListOf(_) => todo!(),
+            Type::ListExact(_) => todo!(),
+            Type::Map(_) => todo!(),
+            Type::String => todo!(),
+            Type::Range => todo!(),
+            _ => {
+                return Err(ValidationError::TypeCheck {
+                    expected: Type::Collection,
+                    actual: collection_type,
+                    position: self.source_position,
+                });
+            }
+        };
+        let key = self.item_id.clone();
+
+        self.context.inherit_all_from(context)?;
+        self.context.set_type(key, item_type)?;
+        self.item_id.validate(_source, &self.context)?;
+        self.block.validate(_source, &self.context)
+    }
+
+    fn run(&self, source: &str, context: &Context) -> Result<Value, RuntimeError> {
+        self.context.inherit_all_from(context)?;
+
+        let expression_run = self.collection.run(source, context)?;
+        let key = &self.item_id;
+
+        if let Value::Range(range) = expression_run {
+            if self.is_async {
+                range.into_par_iter().try_for_each(|integer| {
+                    self.context.add_allowance(key)?;
+                    self.context
+                        .set_value(key.clone(), Value::Integer(integer))?;
+                    self.block.run(source, &self.context).map(|_value| ())
+                })?;
+            } else {
+                for i in range {
+                    self.context.add_allowance(key)?;
+                    self.context.set_value(key.clone(), Value::Integer(i))?;
+                    self.block.run(source, &self.context)?;
+                }
+            }
+
+            return Ok(Value::none());
+        }
+
+        if let Value::List(list) = &expression_run {
+            if self.is_async {
+                list.items()?.par_iter().try_for_each(|value| {
+                    self.context.add_allowance(key)?;
+                    self.context.set_value(key.clone(), value.clone())?;
+                    self.block.run(source, &self.context).map(|_value| ())
+                })?;
+            } else {
+                for value in list.items()?.iter() {
+                    self.context.add_allowance(key)?;
+                    self.context.set_value(key.clone(), value.clone())?;
+                    self.block.run(source, &self.context)?;
+                }
+            }
+        }
+
+        Ok(Value::none())
+    }
+}
+
+impl Format for For {
+    fn format(&self, output: &mut String, indent_level: u8) {
+        if self.is_async {
+            output.push_str("async for ");
+        } else {
+            output.push_str("for ");
+        }
+
+        self.item_id.format(output, indent_level);
+        output.push_str(" in ");
+        self.collection.format(output, indent_level);
+        output.push(' ');
+        self.block.format(output, indent_level);
+    }
+}

src/abstract_tree/function_call.rs

@@ -0,0 +1,202 @@
+use serde::{Deserialize, Serialize};
+
+use crate::{
+    built_in_functions::Callable,
+    error::{RuntimeError, SyntaxError, ValidationError},
+    AbstractTree, Context, Expression, Format, Function, FunctionExpression, SourcePosition,
+    SyntaxNode, Type, Value,
+};
+
+/// A function being invoked and the arguments it is being passed.
+#[derive(Debug, Clone, Serialize, Deserialize, Eq, PartialEq, PartialOrd, Ord)]
+pub struct FunctionCall {
+    function_expression: FunctionExpression,
+    arguments: Vec<Expression>,
+    syntax_position: SourcePosition,
+}
+
+impl FunctionCall {
+    /// Returns a new FunctionCall.
+    pub fn new(
+        function_expression: FunctionExpression,
+        arguments: Vec<Expression>,
+        syntax_position: SourcePosition,
+    ) -> Self {
+        Self {
+            function_expression,
+            arguments,
+            syntax_position,
+        }
+    }
+}
+
+impl AbstractTree for FunctionCall {
+    fn from_syntax(node: SyntaxNode, source: &str, context: &Context) -> Result<Self, SyntaxError> {
+        SyntaxError::expect_syntax_node("function_call", node)?;
+
+        let function_node = node.child(0).unwrap();
+        let function_expression = FunctionExpression::from_syntax(function_node, source, context)?;
+
+        let mut arguments = Vec::new();
+
+        for index in 2..node.child_count() - 1 {
+            let child = node.child(index).unwrap();
+
+            if child.is_named() {
+                let expression = Expression::from_syntax(child, source, context)?;
+
+                arguments.push(expression);
+            }
+        }
+
+        Ok(FunctionCall {
+            function_expression,
+            arguments,
+            syntax_position: node.range().into(),
+        })
+    }
+
+    fn expected_type(&self, context: &Context) -> Result<Type, ValidationError> {
+        match &self.function_expression {
+            FunctionExpression::Identifier(identifier) => {
+                let identifier_type = identifier.expected_type(context)?;
+
+                if let Type::Function {
+                    parameter_types: _,
+                    return_type,
+                } = &identifier_type
+                {
+                    Ok(*return_type.clone())
+                } else {
+                    Ok(identifier_type)
+                }
+            }
+            FunctionExpression::FunctionCall(function_call) => function_call.expected_type(context),
+            FunctionExpression::Value(value_node) => {
+                let value_type = value_node.expected_type(context)?;
+
+                if let Type::Function { return_type, .. } = value_type {
+                    Ok(*return_type)
+                } else {
+                    Ok(value_type)
+                }
+            }
+            FunctionExpression::Index(index) => {
+                let index_type = index.expected_type(context)?;
+
+                if let Type::Function { return_type, .. } = index_type {
+                    Ok(*return_type)
+                } else {
+                    Ok(index_type)
+                }
+            }
+        }
+    }
+
+    fn validate(&self, _source: &str, context: &Context) -> Result<(), ValidationError> {
+        self.function_expression.validate(_source, context)?;
+
+        let function_expression_type = self.function_expression.expected_type(context)?;
+
+        let parameter_types = if let Type::Function {
+            parameter_types, ..
+        } = function_expression_type
+        {
+            parameter_types
+        } else {
+            return Err(ValidationError::TypeCheckExpectedFunction {
+                actual: function_expression_type,
+                position: self.syntax_position,
+            });
+        };
+
+        if self.arguments.len() != parameter_types.len() {
+            return Err(ValidationError::ExpectedFunctionArgumentAmount {
+                expected: parameter_types.len(),
+                actual: self.arguments.len(),
+                position: self.syntax_position,
+            });
+        }
+
+        for (index, expression) in self.arguments.iter().enumerate() {
+            expression.validate(_source, context)?;
+
+            if let Some(expected) = parameter_types.get(index) {
+                let actual = expression.expected_type(context)?;
+
+                if !expected.accepts(&actual) {
+                    return Err(ValidationError::TypeCheck {
+                        expected: expected.clone(),
+                        actual,
+                        position: self.syntax_position,
+                    });
+                }
+            }
+        }
+
+        Ok(())
+    }
+
+    fn run(&self, source: &str, context: &Context) -> Result<Value, RuntimeError> {
+        let value = match &self.function_expression {
+            FunctionExpression::Identifier(identifier) => {
+                if let Some(value) = context.get_value(identifier)? {
+                    value.clone()
+                } else {
+                    return Err(RuntimeError::ValidationFailure(
+                        ValidationError::VariableIdentifierNotFound(identifier.clone()),
+                    ));
+                }
+            }
+            FunctionExpression::FunctionCall(function_call) => {
+                function_call.run(source, context)?
+            }
+            FunctionExpression::Value(value_node) => value_node.run(source, context)?,
+            FunctionExpression::Index(index) => index.run(source, context)?,
+        };
+        let function = value.as_function()?;
+
+        match function {
+            Function::BuiltIn(built_in_function) => {
+                let mut arguments = Vec::with_capacity(self.arguments.len());
+
+                for expression in &self.arguments {
+                    let value = expression.run(source, context)?;
+
+                    arguments.push(value);
+                }
+
+                built_in_function.call(&arguments, source, context)
+            }
+            Function::ContextDefined(function_node) => {
+                let call_context = Context::with_variables_from(function_node.context())?;
+
+                call_context.inherit_from(context)?;
+
+                let parameter_expression_pairs =
+                    function_node.parameters().iter().zip(self.arguments.iter());
+
+                for (identifier, expression) in parameter_expression_pairs {
+                    let value = expression.run(source, context)?;
+
+                    call_context.set_value(identifier.clone(), value)?;
+                }
+
+                function_node.body().run(source, &call_context)
+            }
+        }
+    }
+}
+
+impl Format for FunctionCall {
+    fn format(&self, output: &mut String, indent_level: u8) {
+        self.function_expression.format(output, indent_level);
+        output.push('(');
+
+        for expression in &self.arguments {
+            expression.format(output, indent_level);
+        }
+
+        output.push(')');
+    }
+}

src/abstract_tree/function_expression.rs

@@ -0,0 +1,91 @@
+use serde::{Deserialize, Serialize};
+
+use crate::{
+    error::{RuntimeError, SyntaxError, ValidationError},
+    AbstractTree, Context, Format, FunctionCall, Identifier, Index, SyntaxNode, Type, Value,
+    ValueNode,
+};
+
+#[derive(Debug, Clone, Serialize, Deserialize, Eq, PartialEq, PartialOrd, Ord)]
+pub enum FunctionExpression {
+    Identifier(Identifier),
+    FunctionCall(Box<FunctionCall>),
+    Value(ValueNode),
+    Index(Index),
+}
+
+impl AbstractTree for FunctionExpression {
+    fn from_syntax(node: SyntaxNode, source: &str, context: &Context) -> Result<Self, SyntaxError> {
+        SyntaxError::expect_syntax_node("function_expression", node)?;
+
+        let first_child = node.child(0).unwrap();
+        let child = if first_child.is_named() {
+            first_child
+        } else {
+            node.child(1).unwrap()
+        };
+
+        let function_expression = match child.kind() {
+            "identifier" => {
+                FunctionExpression::Identifier(Identifier::from_syntax(child, source, context)?)
+            }
+
+            "function_call" => FunctionExpression::FunctionCall(Box::new(
+                FunctionCall::from_syntax(child, source, context)?,
+            )),
+            "value" => FunctionExpression::Value(ValueNode::from_syntax(child, source, context)?),
+            "index" => FunctionExpression::Index(Index::from_syntax(child, source, context)?),
+            _ => {
+                return Err(SyntaxError::UnexpectedSyntaxNode {
+                    expected: "identifier, function call, value or index".to_string(),
+                    actual: child.kind().to_string(),
+                    position: node.range().into(),
+                })
+            }
+        };
+
+        Ok(function_expression)
+    }
+
+    fn expected_type(&self, context: &Context) -> Result<Type, ValidationError> {
+        match self {
+            FunctionExpression::Identifier(identifier) => identifier.expected_type(context),
+            FunctionExpression::FunctionCall(function_call) => function_call.expected_type(context),
+            FunctionExpression::Value(value_node) => value_node.expected_type(context),
+            FunctionExpression::Index(index) => index.expected_type(context),
+        }
+    }
+
+    fn validate(&self, _source: &str, _context: &Context) -> Result<(), ValidationError> {
+        match self {
+            FunctionExpression::Identifier(identifier) => identifier.validate(_source, _context),
+            FunctionExpression::FunctionCall(function_call) => {
+                function_call.validate(_source, _context)
+            }
+            FunctionExpression::Value(value_node) => value_node.validate(_source, _context),
+            FunctionExpression::Index(index) => index.validate(_source, _context),
+        }
+    }
+
+    fn run(&self, source: &str, context: &Context) -> Result<Value, RuntimeError> {
+        match self {
+            FunctionExpression::Identifier(identifier) => identifier.run(source, context),
+            FunctionExpression::FunctionCall(function_call) => function_call.run(source, context),
+            FunctionExpression::Value(value_node) => value_node.run(source, context),
+            FunctionExpression::Index(index) => index.run(source, context),
+        }
+    }
+}
+
+impl Format for FunctionExpression {
+    fn format(&self, output: &mut String, indent_level: u8) {
+        match self {
+            FunctionExpression::Value(value_node) => value_node.format(output, indent_level),
+            FunctionExpression::Identifier(identifier) => identifier.format(output, indent_level),
+            FunctionExpression::FunctionCall(function_call) => {
+                function_call.format(output, indent_level)
+            }
+            FunctionExpression::Index(index) => index.format(output, indent_level),
+        }
+    }
+}

src/abstract_tree/function_node.rs

@@ -0,0 +1,179 @@
+use std::fmt::{self, Display, Formatter};
+
+use serde::{Deserialize, Serialize};
+
+use crate::{
+    error::{RuntimeError, SyntaxError, ValidationError},
+    AbstractTree, Block, Context, Format, Function, Identifier, SourcePosition, SyntaxNode, Type,
+    TypeSpecification, Value,
+};
+
+#[derive(Debug, Clone, Serialize, Deserialize, PartialEq, Eq, PartialOrd, Ord)]
+pub struct FunctionNode {
+    parameters: Vec<Identifier>,
+    body: Block,
+    r#type: Type,
+    syntax_position: SourcePosition,
+
+    #[serde(skip)]
+    context: Context,
+}
+
+impl FunctionNode {
+    pub fn parameters(&self) -> &Vec<Identifier> {
+        &self.parameters
+    }
+
+    pub fn body(&self) -> &Block {
+        &self.body
+    }
+
+    pub fn r#type(&self) -> &Type {
+        &self.r#type
+    }
+
+    pub fn syntax_position(&self) -> &SourcePosition {
+        &self.syntax_position
+    }
+
+    pub fn context(&self) -> &Context {
+        &self.context
+    }
+
+    pub fn return_type(&self) -> &Type {
+        match &self.r#type {
+            Type::Function {
+                parameter_types: _,
+                return_type,
+            } => return_type.as_ref(),
+            _ => &Type::None,
+        }
+    }
+}
+
+impl AbstractTree for FunctionNode {
+    fn from_syntax(node: SyntaxNode, source: &str, context: &Context) -> Result<Self, SyntaxError> {
+        SyntaxError::expect_syntax_node("function", node)?;
+
+        let child_count = node.child_count();
+        let mut parameters = Vec::new();
+        let mut parameter_types = Vec::new();
+
+        for index in 1..child_count - 3 {
+            let child = node.child(index).unwrap();
+
+            if child.kind() == "identifier" {
+                let identifier = Identifier::from_syntax(child, source, context)?;
+
+                parameters.push(identifier);
+            }
+
+            if child.kind() == "type_specification" {
+                let type_specification = TypeSpecification::from_syntax(child, source, context)?;
+
+                parameter_types.push(type_specification.take_inner());
+            }
+        }
+
+        let return_type_node = node.child(child_count - 2).unwrap();
+        let return_type = TypeSpecification::from_syntax(return_type_node, source, context)?;
+
+        let function_context = Context::with_variables_from(context)?;
+
+        let body_node = node.child(child_count - 1).unwrap();
+        let body = Block::from_syntax(body_node, source, &function_context)?;
+
+        let r#type = Type::function(parameter_types, return_type.take_inner());
+        let syntax_position = node.range().into();
+
+        Ok(FunctionNode {
+            parameters,
+            body,
+            r#type,
+            syntax_position,
+            context: function_context,
+        })
+    }
+
+    fn expected_type(&self, _context: &Context) -> Result<Type, ValidationError> {
+        Ok(self.r#type().clone())
+    }
+
+    fn validate(&self, source: &str, context: &Context) -> Result<(), ValidationError> {
+        if let Type::Function {
+            parameter_types,
+            return_type,
+        } = &self.r#type
+        {
+            self.context.inherit_from(context)?;
+
+            for (parameter, r#type) in self.parameters.iter().zip(parameter_types.iter()) {
+                self.context.set_type(parameter.clone(), r#type.clone())?;
+            }
+
+            let actual = self.body.expected_type(&self.context)?;
+
+            if !return_type.accepts(&actual) {
+                return Err(ValidationError::TypeCheck {
+                    expected: return_type.as_ref().clone(),
+                    actual,
+                    position: self.syntax_position,
+                });
+            }
+
+            self.body.validate(source, &self.context)?;
+
+            Ok(())
+        } else {
+            Err(ValidationError::TypeCheckExpectedFunction {
+                actual: self.r#type.clone(),
+                position: self.syntax_position,
+            })
+        }
+    }
+
+    fn run(&self, _source: &str, context: &Context) -> Result<Value, RuntimeError> {
+        self.context.inherit_from(context)?;
+
+        let self_as_value = Value::Function(Function::ContextDefined(self.clone()));
+
+        Ok(self_as_value)
+    }
+}
+
+impl Format for FunctionNode {
+    fn format(&self, output: &mut String, indent_level: u8) {
+        let (parameter_types, return_type) = if let Type::Function {
+            parameter_types,
+            return_type,
+        } = &self.r#type
+        {
+            (parameter_types, return_type)
+        } else {
+            return;
+        };
+
+        output.push('(');
+
+        for (identifier, r#type) in self.parameters.iter().zip(parameter_types.iter()) {
+            identifier.format(output, indent_level);
+            output.push_str(" <");
+            r#type.format(output, indent_level);
+            output.push('>');
+        }
+
+        output.push_str(") <");
+        return_type.format(output, indent_level);
+        output.push_str("> ");
+        self.body.format(output, indent_level);
+    }
+}
+
+impl Display for FunctionNode {
+    fn fmt(&self, f: &mut Formatter) -> fmt::Result {
+        let mut string = String::new();
+
+        self.format(&mut string, 0);
+        f.write_str(&string)
+    }
+}

src/abstract_tree/identifier.rs

@@ -0,0 +1,167 @@
+use std::{
+    fmt::{self, Display, Formatter},
+    sync::Arc,
+};
+
+use serde::{de::Visitor, Deserialize, Serialize};
+
+use crate::{
+    built_in_identifiers::all_built_in_identifiers,
+    built_in_values::all_built_in_values,
+    error::{RuntimeError, SyntaxError, ValidationError},
+    AbstractTree, Context, Format, SyntaxNode, Type, Value,
+};
+
+/// A string by which a variable is known to a context.
+///
+/// Every variable is a key-value pair. An identifier holds the key part of that
+/// pair. Its inner value can be used to retrieve a Value instance from a Map.
+#[derive(Debug, Clone, Eq, PartialEq, PartialOrd, Ord, Hash)]
+pub struct Identifier(Arc<String>);
+
+impl Identifier {
+    pub fn new(key: &str) -> Self {
+        for built_in_identifier in all_built_in_identifiers() {
+            let identifier = built_in_identifier.get();
+
+            if &key == identifier.inner().as_ref() {
+                return identifier.clone();
+            }
+        }
+
+        Identifier(Arc::new(key.to_string()))
+    }
+
+    pub fn from_raw_parts(arc: Arc<String>) -> Self {
+        Identifier(arc)
+    }
+
+    pub fn inner(&self) -> &Arc<String> {
+        &self.0
+    }
+
+    pub fn contains(&self, string: &str) -> bool {
+        self.0.as_ref() == string
+    }
+}
+
+impl AbstractTree for Identifier {
+    fn from_syntax(
+        node: SyntaxNode,
+        source: &str,
+        _context: &Context,
+    ) -> Result<Self, SyntaxError> {
+        SyntaxError::expect_syntax_node("identifier", node)?;
+
+        let text = &source[node.byte_range()];
+
+        debug_assert!(!text.is_empty());
+
+        Ok(Identifier::new(text))
+    }
+
+    fn validate(&self, _source: &str, context: &Context) -> Result<(), ValidationError> {
+        let variable_exists = context.add_allowance(self)?;
+
+        if variable_exists {
+            Ok(())
+        } else {
+            for built_in_value in all_built_in_values() {
+                if built_in_value.name() == self.inner().as_ref() {
+                    return Ok(());
+                }
+            }
+
+            Err(ValidationError::VariableIdentifierNotFound(self.clone()))
+        }
+    }
+
+    fn expected_type(&self, context: &Context) -> Result<Type, ValidationError> {
+        if let Some(r#type) = context.get_type(self)? {
+            Ok(r#type)
+        } else {
+            for built_in_value in all_built_in_values() {
+                if built_in_value.name() == self.inner().as_ref() {
+                    return Ok(built_in_value.get().r#type()?);
+                }
+            }
+
+            Err(ValidationError::VariableIdentifierNotFound(self.clone()))
+        }
+    }
+
+    fn run(&self, _source: &str, context: &Context) -> Result<Value, RuntimeError> {
+        if let Some(value) = context.get_value(self)? {
+            return Ok(value);
+        } else {
+            for built_in_value in all_built_in_values() {
+                if built_in_value.name() == self.inner().as_ref() {
+                    return Ok(built_in_value.get().clone());
+                }
+            }
+        }
+
+        Err(RuntimeError::ValidationFailure(
+            ValidationError::VariableIdentifierNotFound(self.clone()),
+        ))
+    }
+}
+
+impl Format for Identifier {
+    fn format(&self, output: &mut String, _indent_level: u8) {
+        output.push_str(&self.0);
+    }
+}
+
+impl From<String> for Identifier {
+    fn from(value: String) -> Self {
+        Identifier::from_raw_parts(Arc::new(value))
+    }
+}
+
+impl From<&str> for Identifier {
+    fn from(value: &str) -> Self {
+        Identifier::new(value)
+    }
+}
+
+impl Display for Identifier {
+    fn fmt(&self, f: &mut Formatter) -> fmt::Result {
+        write!(f, "{}", self.0)
+    }
+}
+
+impl Serialize for Identifier {
+    fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
+    where
+        S: serde::Serializer,
+    {
+        serializer.serialize_str(self.0.as_ref())
+    }
+}
+
+impl<'de> Deserialize<'de> for Identifier {
+    fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
+    where
+        D: serde::Deserializer<'de>,
+    {
+        deserializer.deserialize_string(IdentifierVisitor)
+    }
+}
+
+struct IdentifierVisitor;
+
+impl<'de> Visitor<'de> for IdentifierVisitor {
+    type Value = Identifier;
+
+    fn expecting(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        formatter.write_str("valid UFT-8 sequence")
+    }
+
+    fn visit_string<E>(self, v: String) -> Result<Self::Value, E>
+    where
+        E: serde::de::Error,
+    {
+        Ok(Identifier(Arc::new(v)))
+    }
+}

src/abstract_tree/if_else.rs

@@ -0,0 +1,160 @@
+use serde::{Deserialize, Serialize};
+
+use crate::{
+    error::{RuntimeError, SyntaxError, ValidationError},
+    AbstractTree, Block, Context, Expression, Format, SourcePosition, SyntaxNode, Type, Value,
+};
+
+#[derive(Debug, Clone, Serialize, Deserialize, Eq, PartialEq, PartialOrd, Ord)]
+pub struct IfElse {
+    if_expression: Expression,
+    if_block: Block,
+    else_if_expressions: Vec<Expression>,
+    else_if_blocks: Vec<Block>,
+    else_block: Option<Block>,
+    source_position: SourcePosition,
+}
+
+impl AbstractTree for IfElse {
+    fn from_syntax(node: SyntaxNode, source: &str, context: &Context) -> Result<Self, SyntaxError> {
+        let if_expression_node = node.child(0).unwrap().child(1).unwrap();
+        let if_expression = Expression::from_syntax(if_expression_node, source, context)?;
+
+        let if_block_node = node.child(0).unwrap().child(2).unwrap();
+        let if_block = Block::from_syntax(if_block_node, source, context)?;
+
+        let child_count = node.child_count();
+        let mut else_if_expressions = Vec::new();
+        let mut else_if_blocks = Vec::new();
+        let mut else_block = None;
+
+        for index in 1..child_count {
+            let child = node.child(index).unwrap();
+
+            if child.kind() == "else_if" {
+                let expression_node = child.child(1).unwrap();
+                let expression = Expression::from_syntax(expression_node, source, context)?;
+
+                else_if_expressions.push(expression);
+
+                let block_node = child.child(2).unwrap();
+                let block = Block::from_syntax(block_node, source, context)?;
+
+                else_if_blocks.push(block);
+            }
+
+            if child.kind() == "else" {
+                let else_node = child.child(1).unwrap();
+                else_block = Some(Block::from_syntax(else_node, source, context)?);
+            }
+        }
+
+        Ok(IfElse {
+            if_expression,
+            if_block,
+            else_if_expressions,
+            else_if_blocks,
+            else_block,
+            source_position: SourcePosition::from(node.range()),
+        })
+    }
+
+    fn expected_type(&self, context: &Context) -> Result<Type, ValidationError> {
+        self.if_block.expected_type(context)
+    }
+
+    fn validate(&self, _source: &str, context: &Context) -> Result<(), ValidationError> {
+        self.if_expression.validate(_source, context)?;
+        self.if_block.validate(_source, context)?;
+
+        let expected = self.if_block.expected_type(context)?;
+        let else_ifs = self
+            .else_if_expressions
+            .iter()
+            .zip(self.else_if_blocks.iter());
+
+        for (expression, block) in else_ifs {
+            expression.validate(_source, context)?;
+            block.validate(_source, context)?;
+
+            let actual = block.expected_type(context)?;
+
+            if !expected.accepts(&actual) {
+                return Err(ValidationError::TypeCheck {
+                    expected,
+                    actual,
+                    position: self.source_position,
+                });
+            }
+        }
+
+        if let Some(block) = &self.else_block {
+            block.validate(_source, context)?;
+
+            let actual = block.expected_type(context)?;
+
+            if !expected.accepts(&actual) {
+                return Err(ValidationError::TypeCheck {
+                    expected,
+                    actual,
+                    position: self.source_position,
+                });
+            }
+        }
+
+        Ok(())
+    }
+
+    fn run(&self, source: &str, context: &Context) -> Result<Value, RuntimeError> {
+        let if_boolean = self.if_expression.run(source, context)?.as_boolean()?;
+
+        if if_boolean {
+            self.if_block.run(source, context)
+        } else {
+            let else_ifs = self
+                .else_if_expressions
+                .iter()
+                .zip(self.else_if_blocks.iter());
+
+            for (expression, block) in else_ifs {
+                let if_boolean = expression.run(source, context)?.as_boolean()?;
+
+                if if_boolean {
+                    return block.run(source, context);
+                }
+            }
+
+            if let Some(block) = &self.else_block {
+                block.run(source, context)
+            } else {
+                Ok(Value::none())
+            }
+        }
+    }
+}
+
+impl Format for IfElse {
+    fn format(&self, output: &mut String, indent_level: u8) {
+        output.push_str("if ");
+        self.if_expression.format(output, indent_level);
+        output.push(' ');
+        self.if_block.format(output, indent_level);
+
+        let else_ifs = self
+            .else_if_expressions
+            .iter()
+            .zip(self.else_if_blocks.iter());
+
+        for (expression, block) in else_ifs {
+            output.push_str("else if ");
+            expression.format(output, indent_level);
+            output.push(' ');
+            block.format(output, indent_level);
+        }
+
+        if let Some(block) = &self.else_block {
+            output.push_str("else ");
+            block.format(output, indent_level);
+        }
+    }
+}

src/abstract_tree/index.rs

@@ -0,0 +1,134 @@
+use serde::{Deserialize, Serialize};
+
+use crate::{
+    error::{RuntimeError, SyntaxError, ValidationError},
+    AbstractTree, Context, Format, Identifier, IndexExpression, SourcePosition, SyntaxNode, Type,
+    Value,
+};
+
+/// Abstract representation of an index expression.
+///
+/// An index is a means of accessing values stored in list, maps and strings.
+#[derive(Debug, Clone, Serialize, Deserialize, Eq, PartialEq, PartialOrd, Ord)]
+pub struct Index {
+    pub collection: IndexExpression,
+    pub index: IndexExpression,
+    source_position: SourcePosition,
+}
+
+impl AbstractTree for Index {
+    fn from_syntax(node: SyntaxNode, source: &str, context: &Context) -> Result<Self, SyntaxError> {
+        SyntaxError::expect_syntax_node("index", node)?;
+
+        let collection_node = node.child(0).unwrap();
+        let collection = IndexExpression::from_syntax(collection_node, source, context)?;
+
+        let index_node = node.child(2).unwrap();
+        let index = IndexExpression::from_syntax(index_node, source, context)?;
+
+        Ok(Index {
+            collection,
+            index,
+            source_position: SourcePosition::from(node.range()),
+        })
+    }
+
+    fn expected_type(&self, context: &Context) -> Result<Type, ValidationError> {
+        match self.collection.expected_type(context)? {
+            Type::ListOf(item_type) => Ok(*item_type.clone()),
+            Type::Map(map_types_option) => {
+                if let (Some(map_type), IndexExpression::Identifier(identifier)) =
+                    (map_types_option, &self.index)
+                {
+                    if let Some(r#type) = map_type.get(&identifier) {
+                        Ok(r#type.clone())
+                    } else {
+                        Ok(Type::Any)
+                    }
+                } else {
+                    Ok(Type::Any)
+                }
+            }
+            Type::None => Ok(Type::None),
+            r#type => Ok(r#type),
+        }
+    }
+
+    fn validate(&self, _source: &str, _context: &Context) -> Result<(), ValidationError> {
+        self.collection.validate(_source, _context)?;
+
+        let collection_type = self.collection.expected_type(_context)?;
+
+        if let (Type::Map(type_map_option), IndexExpression::Identifier(identifier)) =
+            (collection_type, &self.index)
+        {
+            if let Some(type_map) = type_map_option {
+                if !type_map.contains_key(identifier) {
+                    return Err(ValidationError::VariableIdentifierNotFound(
+                        identifier.clone(),
+                    ));
+                }
+            }
+        } else {
+            self.index.validate(_source, _context)?;
+        }
+
+        Ok(())
+    }
+
+    fn run(&self, source: &str, context: &Context) -> Result<Value, RuntimeError> {
+        let value = self.collection.run(source, context)?;
+
+        match value {
+            Value::List(list) => {
+                let index = self.index.run(source, context)?.as_integer()? as usize;
+                let item = list.items()?.get(index).cloned().unwrap_or_default();
+
+                Ok(item)
+            }
+            Value::Map(map) => {
+                let map = map.inner();
+
+                let value = if let IndexExpression::Identifier(identifier) = &self.index {
+                    if let Some(value) = map.get(identifier) {
+                        value
+                    } else {
+                        return Err(RuntimeError::ValidationFailure(
+                            ValidationError::VariableIdentifierNotFound(identifier.clone()),
+                        ));
+                    }
+                } else {
+                    let index_value = self.index.run(source, context)?;
+                    let identifier = Identifier::new(index_value.as_string()?);
+
+                    if let Some(value) = map.get(&identifier) {
+                        value
+                    } else {
+                        return Err(RuntimeError::ValidationFailure(
+                            ValidationError::VariableIdentifierNotFound(identifier.clone()),
+                        ));
+                    }
+                };
+
+                Ok(value.clone())
+            }
+            Value::String(string) => {
+                let index = self.index.run(source, context)?.as_integer()? as usize;
+                let item = string.chars().nth(index).unwrap_or_default();
+
+                Ok(Value::string(item.to_string()))
+            }
+            _ => Err(RuntimeError::ValidationFailure(
+                ValidationError::ExpectedCollection { actual: value },
+            )),
+        }
+    }
+}
+
+impl Format for Index {
+    fn format(&self, output: &mut String, indent_level: u8) {
+        self.collection.format(output, indent_level);
+        output.push(':');
+        self.index.format(output, indent_level);
+    }
+}

src/abstract_tree/index_assignment.rs

@@ -0,0 +1,96 @@
+use serde::{Deserialize, Serialize};
+
+use crate::{
+    error::{RuntimeError, SyntaxError, ValidationError},
+    AbstractTree, AssignmentOperator, Context, Format, Identifier, Index, IndexExpression,
+    SourcePosition, Statement, SyntaxNode, Type, Value,
+};
+
+#[derive(Debug, Clone, Serialize, Deserialize, Eq, PartialEq, PartialOrd, Ord)]
+pub struct IndexAssignment {
+    index: Index,
+    operator: AssignmentOperator,
+    statement: Statement,
+    position: SourcePosition,
+}
+
+impl AbstractTree for IndexAssignment {
+    fn from_syntax(node: SyntaxNode, source: &str, context: &Context) -> Result<Self, SyntaxError> {
+        SyntaxError::expect_syntax_node("index_assignment", node)?;
+
+        let index_node = node.child(0).unwrap();
+        let index = Index::from_syntax(index_node, source, context)?;
+
+        let operator_node = node.child(1).unwrap();
+        let operator = AssignmentOperator::from_syntax(operator_node, source, context)?;
+
+        let statement_node = node.child(2).unwrap();
+        let statement = Statement::from_syntax(statement_node, source, context)?;
+
+        Ok(IndexAssignment {
+            index,
+            operator,
+            statement,
+            position: node.range().into(),
+        })
+    }
+
+    fn expected_type(&self, _context: &Context) -> Result<Type, ValidationError> {
+        Ok(Type::None)
+    }
+
+    fn validate(&self, _source: &str, _context: &Context) -> Result<(), ValidationError> {
+        self.index.validate(_source, _context)?;
+        self.statement.validate(_source, _context)
+    }
+
+    fn run(&self, source: &str, context: &Context) -> Result<Value, RuntimeError> {
+        let _index_collection = self.index.collection.run(source, context)?;
+        let index_identifier = if let IndexExpression::Identifier(identifier) = &self.index.index {
+            identifier
+        } else {
+            let index_run = self.index.index.run(source, context)?;
+            let expected_identifier = Identifier::new(index_run.as_string()?);
+
+            return Err(RuntimeError::ValidationFailure(
+                ValidationError::VariableIdentifierNotFound(expected_identifier),
+            ));
+        };
+
+        let value = self.statement.run(source, context)?;
+
+        let new_value = match self.operator {
+            AssignmentOperator::PlusEqual => {
+                if let Some(previous_value) = context.get_value(index_identifier)? {
+                    previous_value.add(value, self.position)?
+                } else {
+                    return Err(RuntimeError::ValidationFailure(
+                        ValidationError::VariableIdentifierNotFound(index_identifier.clone()),
+                    ));
+                }
+            }
+            AssignmentOperator::MinusEqual => {
+                if let Some(previous_value) = context.get_value(index_identifier)? {
+                    previous_value.subtract(value, self.position)?
+                } else {
+                    Value::none()
+                }
+            }
+            AssignmentOperator::Equal => value,
+        };
+
+        context.set_value(index_identifier.clone(), new_value)?;
+
+        Ok(Value::none())
+    }
+}
+
+impl Format for IndexAssignment {
+    fn format(&self, output: &mut String, indent_level: u8) {
+        self.index.format(output, indent_level);
+        output.push(' ');
+        self.operator.format(output, indent_level);
+        output.push(' ');
+        self.statement.format(output, indent_level);
+    }
+}

src/abstract_tree/index_expression.rs

@@ -0,0 +1,98 @@
+use serde::{Deserialize, Serialize};
+
+use crate::{
+    error::{RuntimeError, SyntaxError, ValidationError},
+    value_node::ValueNode,
+    AbstractTree, Context, Format, FunctionCall, Identifier, Index, SyntaxNode, Type, Value,
+};
+
+#[derive(Debug, Clone, Serialize, Deserialize, Eq, PartialEq, PartialOrd, Ord)]
+pub enum IndexExpression {
+    Value(ValueNode),
+    Identifier(Identifier),
+    Index(Box<Index>),
+    FunctionCall(Box<FunctionCall>),
+}
+
+impl AbstractTree for IndexExpression {
+    fn from_syntax(node: SyntaxNode, source: &str, context: &Context) -> Result<Self, SyntaxError> {
+        SyntaxError::expect_syntax_node("index_expression", node)?;
+
+        let first_child = node.child(0).unwrap();
+        let child = if first_child.is_named() {
+            first_child
+        } else {
+            node.child(1).unwrap()
+        };
+
+        let abstract_node = match child.kind() {
+            "value" => IndexExpression::Value(ValueNode::from_syntax(child, source, context)?),
+            "identifier" => {
+                IndexExpression::Identifier(Identifier::from_syntax(child, source, context)?)
+            }
+            "index" => {
+                IndexExpression::Index(Box::new(Index::from_syntax(child, source, context)?))
+            }
+            "function_call" => IndexExpression::FunctionCall(Box::new(FunctionCall::from_syntax(
+                child, source, context,
+            )?)),
+            _ => {
+                return Err(SyntaxError::UnexpectedSyntaxNode {
+                    expected: "value, identifier, index or function call".to_string(),
+                    actual: child.kind().to_string(),
+                    position: node.range().into(),
+                })
+            }
+        };
+
+        Ok(abstract_node)
+    }
+
+    fn expected_type(&self, context: &Context) -> Result<Type, ValidationError> {
+        match self {
+            IndexExpression::Value(value_node) => value_node.expected_type(context),
+            IndexExpression::Identifier(identifier) => identifier.expected_type(context),
+            IndexExpression::Index(index) => index.expected_type(context),
+            IndexExpression::FunctionCall(function_call) => function_call.expected_type(context),
+        }
+    }
+
+    fn validate(&self, _source: &str, context: &Context) -> Result<(), ValidationError> {
+        match self {
+            IndexExpression::Value(value_node) => value_node.validate(_source, context),
+            IndexExpression::Identifier(identifier) => {
+                context.add_allowance(identifier)?;
+
+                Ok(())
+            }
+            IndexExpression::Index(index) => index.validate(_source, context),
+            IndexExpression::FunctionCall(function_call) => {
+                function_call.validate(_source, context)
+            }
+        }
+    }
+
+    fn run(&self, source: &str, context: &Context) -> Result<Value, RuntimeError> {
+        match self {
+            IndexExpression::Value(value_node) => value_node.run(source, context),
+            IndexExpression::Identifier(identifier) => identifier.run(source, context),
+            IndexExpression::Index(index) => index.run(source, context),
+            IndexExpression::FunctionCall(function_call) => function_call.run(source, context),
+        }
+    }
+}
+
+impl Format for IndexExpression {
+    fn format(&self, output: &mut String, indent_level: u8) {
+        match self {
+            IndexExpression::Value(value_node) => {
+                value_node.format(output, indent_level);
+            }
+            IndexExpression::Identifier(identifier) => identifier.format(output, indent_level),
+            IndexExpression::FunctionCall(function_call) => {
+                function_call.format(output, indent_level)
+            }
+            IndexExpression::Index(index) => index.format(output, indent_level),
+        }
+    }
+}

src/abstract_tree/logic.rs

@@ -0,0 +1,95 @@
+use serde::{Deserialize, Serialize};
+
+use crate::{
+    error::{RuntimeError, SyntaxError, ValidationError},
+    AbstractTree, Context, Expression, Format, LogicOperator, SyntaxNode, Type, Value,
+};
+
+/// Abstract representation of a logic expression.
+#[derive(Debug, Clone, Serialize, Deserialize, Eq, PartialEq, PartialOrd, Ord)]
+pub struct Logic {
+    left: Expression,
+    operator: LogicOperator,
+    right: Expression,
+}
+
+impl AbstractTree for Logic {
+    fn from_syntax(node: SyntaxNode, source: &str, context: &Context) -> Result<Self, SyntaxError> {
+        SyntaxError::expect_syntax_node("logic", node)?;
+
+        let first_node = node.child(0).unwrap();
+        let (left_node, operator_node, right_node) = {
+            if first_node.is_named() {
+                (first_node, node.child(1).unwrap(), node.child(2).unwrap())
+            } else {
+                (
+                    node.child(1).unwrap(),
+                    node.child(2).unwrap(),
+                    node.child(3).unwrap(),
+                )
+            }
+        };
+        let left = Expression::from_syntax(left_node, source, context)?;
+        let operator = LogicOperator::from_syntax(operator_node, source, context)?;
+        let right = Expression::from_syntax(right_node, source, context)?;
+
+        Ok(Logic {
+            left,
+            operator,
+            right,
+        })
+    }
+
+    fn expected_type(&self, _context: &Context) -> Result<Type, ValidationError> {
+        Ok(Type::Boolean)
+    }
+
+    fn validate(&self, _source: &str, _context: &Context) -> Result<(), ValidationError> {
+        log::info!("VALIDATE logic expression");
+
+        self.left.validate(_source, _context)?;
+        self.right.validate(_source, _context)
+    }
+
+    fn run(&self, source: &str, context: &Context) -> Result<Value, RuntimeError> {
+        let left = self.left.run(source, context)?;
+        let right = self.right.run(source, context)?;
+
+        log::info!("RUN logic expression: {left} {} {right}", self.operator);
+
+        let result = match self.operator {
+            LogicOperator::Equal => {
+                if let (Ok(left_num), Ok(right_num)) = (left.as_number(), right.as_number()) {
+                    left_num == right_num
+                } else {
+                    left == right
+                }
+            }
+            LogicOperator::NotEqual => {
+                if let (Ok(left_num), Ok(right_num)) = (left.as_number(), right.as_number()) {
+                    left_num != right_num
+                } else {
+                    left != right
+                }
+            }
+            LogicOperator::And => left.as_boolean()? && right.as_boolean()?,
+            LogicOperator::Or => left.as_boolean()? || right.as_boolean()?,
+            LogicOperator::Greater => left > right,
+            LogicOperator::Less => left < right,
+            LogicOperator::GreaterOrEqual => left >= right,
+            LogicOperator::LessOrEqual => left <= right,
+        };
+
+        Ok(Value::Boolean(result))
+    }
+}
+
+impl Format for Logic {
+    fn format(&self, output: &mut String, indent_level: u8) {
+        self.left.format(output, indent_level);
+        output.push(' ');
+        self.operator.format(output, indent_level);
+        output.push(' ');
+        self.right.format(output, indent_level);
+    }
+}

src/abstract_tree/logic_operator.rs

@@ -0,0 +1,93 @@
+use std::fmt::{self, Display, Formatter};
+
+use serde::{Deserialize, Serialize};
+
+use crate::{
+    error::{RuntimeError, SyntaxError, ValidationError},
+    AbstractTree, Context, Format, SyntaxNode, Type, Value,
+};
+
+#[derive(Debug, Clone, Serialize, Deserialize, Eq, PartialEq, PartialOrd, Ord)]
+pub enum LogicOperator {
+    Equal,
+    NotEqual,
+    And,
+    Or,
+    Greater,
+    Less,
+    GreaterOrEqual,
+    LessOrEqual,
+}
+
+impl AbstractTree for LogicOperator {
+    fn from_syntax(
+        node: SyntaxNode,
+        _source: &str,
+        _context: &Context,
+    ) -> Result<Self, SyntaxError> {
+        SyntaxError::expect_syntax_node("logic_operator", node)?;
+
+        let operator_node = node.child(0).unwrap();
+        let operator = match operator_node.kind() {
+            "==" => LogicOperator::Equal,
+            "!=" => LogicOperator::NotEqual,
+            "&&" => LogicOperator::And,
+            "||" => LogicOperator::Or,
+            ">" => LogicOperator::Greater,
+            "<" => LogicOperator::Less,
+            ">=" => LogicOperator::GreaterOrEqual,
+            "<=" => LogicOperator::LessOrEqual,
+            _ => {
+                return Err(SyntaxError::UnexpectedSyntaxNode {
+                    expected: "==, !=, &&, ||, >, <, >= or <=".to_string(),
+                    actual: operator_node.kind().to_string(),
+                    position: node.range().into(),
+                })
+            }
+        };
+
+        Ok(operator)
+    }
+
+    fn expected_type(&self, _context: &Context) -> Result<Type, ValidationError> {
+        Ok(Type::None)
+    }
+
+    fn validate(&self, _source: &str, _context: &Context) -> Result<(), ValidationError> {
+        Ok(())
+    }
+
+    fn run(&self, _source: &str, _context: &Context) -> Result<Value, RuntimeError> {
+        Ok(Value::none())
+    }
+}
+
+impl Format for LogicOperator {
+    fn format(&self, output: &mut String, _indent_level: u8) {
+        match self {
+            LogicOperator::Equal => output.push('='),
+            LogicOperator::NotEqual => output.push_str("!="),
+            LogicOperator::And => output.push_str("&&"),
+            LogicOperator::Or => output.push_str("||"),
+            LogicOperator::Greater => output.push('>'),
+            LogicOperator::Less => output.push('<'),
+            LogicOperator::GreaterOrEqual => output.push_str(">="),
+            LogicOperator::LessOrEqual => output.push_str("<="),
+        }
+    }
+}
+
+impl Display for LogicOperator {
+    fn fmt(&self, f: &mut Formatter) -> fmt::Result {
+        match self {
+            LogicOperator::Equal => write!(f, "="),
+            LogicOperator::NotEqual => write!(f, "!="),
+            LogicOperator::And => write!(f, "&&"),
+            LogicOperator::Or => write!(f, "||"),
+            LogicOperator::Greater => write!(f, ">"),
+            LogicOperator::Less => write!(f, "<"),
+            LogicOperator::GreaterOrEqual => write!(f, ">="),
+            LogicOperator::LessOrEqual => write!(f, "<="),
+        }
+    }
+}

src/abstract_tree/map_node.rs

@@ -0,0 +1,117 @@
+use std::collections::BTreeMap;
+
+use serde::{Deserialize, Serialize};
+use tree_sitter::Node as SyntaxNode;
+
+use crate::{
+    error::{RuntimeError, SyntaxError, ValidationError},
+    AbstractTree, Context, Format, Identifier, Map, SourcePosition, Statement, Type,
+    TypeSpecification, Value,
+};
+
+#[derive(Debug, Clone, Serialize, Deserialize, Eq, PartialEq, PartialOrd, Ord)]
+pub struct MapNode {
+    properties: BTreeMap<Identifier, (Statement, Option<Type>)>,
+    position: SourcePosition,
+}
+
+impl MapNode {
+    pub fn properties(&self) -> &BTreeMap<Identifier, (Statement, Option<Type>)> {
+        &self.properties
+    }
+}
+
+impl AbstractTree for MapNode {
+    fn from_syntax(node: SyntaxNode, source: &str, context: &Context) -> Result<Self, SyntaxError> {
+        SyntaxError::expect_syntax_node("map", node)?;
+
+        let mut properties = BTreeMap::new();
+        let mut current_identifier = None;
+        let mut current_type = None;
+
+        for index in 0..node.child_count() - 1 {
+            let child = node.child(index).unwrap();
+
+            if child.kind() == "identifier" {
+                current_identifier = Some(Identifier::from_syntax(child, source, context)?);
+                current_type = None;
+            }
+
+            if child.kind() == "type_specification" {
+                current_type =
+                    Some(TypeSpecification::from_syntax(child, source, context)?.take_inner());
+            }
+
+            if child.kind() == "statement" {
+                let statement = Statement::from_syntax(child, source, context)?;
+
+                if let Some(identifier) = &current_identifier {
+                    properties.insert(identifier.clone(), (statement, current_type.clone()));
+                }
+            }
+        }
+
+        Ok(MapNode {
+            properties,
+            position: SourcePosition::from(node.range()),
+        })
+    }
+
+    fn expected_type(&self, _context: &Context) -> Result<Type, ValidationError> {
+        if self.properties.is_empty() {
+            return Ok(Type::Map(None));
+        }
+
+        let mut type_map = BTreeMap::new();
+
+        for (identifier, (statement, r#type_option)) in &self.properties {
+            let r#type = if let Some(r#type) = type_option {
+                r#type.clone()
+            } else {
+                statement.expected_type(_context)?
+            };
+
+            type_map.insert(identifier.clone(), r#type);
+        }
+
+        Ok(Type::Map(Some(type_map)))
+    }
+
+    fn validate(&self, _source: &str, context: &Context) -> Result<(), ValidationError> {
+        for (_key, (statement, r#type)) in &self.properties {
+            statement.validate(_source, context)?;
+
+            if let Some(expected) = r#type {
+                let actual = statement.expected_type(context)?;
+
+                if !expected.accepts(&actual) {
+                    return Err(ValidationError::TypeCheck {
+                        expected: expected.clone(),
+                        actual,
+                        position: self.position.clone(),
+                    });
+                }
+            }
+        }
+
+        Ok(())
+    }
+
+    fn run(&self, _source: &str, _context: &Context) -> Result<Value, RuntimeError> {
+        let mut map = Map::new();
+
+        for (key, (statement, _)) in &self.properties {
+            let value = statement.run(_source, _context)?;
+
+            map.set(key.clone(), value);
+        }
+
+        Ok(Value::Map(map))
+    }
+}
+
+impl Format for MapNode {
+    fn format(&self, _output: &mut String, _indent_level: u8) {
+        todo!()
+    }
+}

src/abstract_tree/match.rs

@@ -0,0 +1,145 @@
+//! Pattern matching.
+//!
+//! Note that this module is called "match" but is escaped as "r#match" because
+//! "match" is a keyword in Rust.
+use serde::{Deserialize, Serialize};
+use tree_sitter::Node as SyntaxNode;
+
+use crate::{
+    error::{RuntimeError, SyntaxError, ValidationError},
+    AbstractTree, Context, Expression, Format, MatchPattern, Statement, Type, Value,
+};
+
+/// Abstract representation of a match statement.
+#[derive(Debug, Clone, Serialize, Deserialize, Eq, PartialEq, PartialOrd, Ord)]
+pub struct Match {
+    matcher: Expression,
+    options: Vec<(MatchPattern, Statement)>,
+    fallback: Option<Box<Statement>>,
+
+    #[serde(skip)]
+    context: Context,
+}
+
+impl AbstractTree for Match {
+    fn from_syntax(node: SyntaxNode, source: &str, context: &Context) -> Result<Self, SyntaxError> {
+        SyntaxError::expect_syntax_node("match", node)?;
+
+        let matcher_node = node.child(1).unwrap();
+        let matcher = Expression::from_syntax(matcher_node, source, context)?;
+
+        let mut options = Vec::new();
+        let mut previous_pattern = None;
+        let mut next_statement_is_fallback = false;
+        let mut fallback = None;
+
+        for index in 2..node.child_count() {
+            let child = node.child(index).unwrap();
+
+            if child.kind() == "match_pattern" {
+                previous_pattern = Some(MatchPattern::from_syntax(child, source, context)?);
+            }
+
+            if child.kind() == "statement" {
+                let statement = Statement::from_syntax(child, source, context)?;
+
+                if next_statement_is_fallback {
+                    fallback = Some(Box::new(statement));
+                    next_statement_is_fallback = false;
+                } else if let Some(expression) = &previous_pattern {
+                    options.push((expression.clone(), statement));
+                }
+            }
+        }
+
+        Ok(Match {
+            matcher,
+            options,
+            fallback,
+            context: Context::default(),
+        })
+    }
+
+    fn expected_type(&self, context: &Context) -> Result<Type, ValidationError> {
+        let (_, first_statement) = self.options.first().unwrap();
+
+        first_statement.expected_type(context)
+    }
+
+    fn validate(&self, _source: &str, _context: &Context) -> Result<(), ValidationError> {
+        self.matcher.validate(_source, _context)?;
+
+        for (match_pattern, statement) in &self.options {
+            if let MatchPattern::EnumPattern(enum_pattern) = match_pattern {
+                if let Some(identifier) = enum_pattern.inner_identifier() {
+                    self.context.set_type(identifier.clone(), Type::Any)?;
+                }
+            }
+
+            match_pattern.validate(_source, _context)?;
+            statement.validate(_source, &self.context)?;
+        }
+
+        if let Some(statement) = &self.fallback {
+            statement.validate(_source, _context)?;
+        }
+
+        Ok(())
+    }
+
+    fn run(&self, source: &str, context: &Context) -> Result<Value, RuntimeError> {
+        let matcher_value = self.matcher.run(source, context)?;
+
+        for (pattern, statement) in &self.options {
+            if let (Value::Enum(enum_instance), MatchPattern::EnumPattern(enum_pattern)) =
+                (&matcher_value, pattern)
+            {
+                if enum_instance.name() == enum_pattern.name()
+                    && enum_instance.variant() == enum_pattern.variant()
+                {
+                    let statement_context = Context::with_variables_from(context)?;
+
+                    if let (Some(identifier), Some(value)) =
+                        (enum_pattern.inner_identifier(), enum_instance.value())
+                    {
+                        statement_context.set_value(identifier.clone(), value.as_ref().clone())?;
+                    }
+
+                    return statement.run(source, &statement_context);
+                }
+            }
+            let pattern_value = pattern.run(source, context)?;
+
+            if matcher_value == pattern_value {
+                return statement.run(source, context);
+            }
+        }
+
+        if let Some(fallback) = &self.fallback {
+            fallback.run(source, context)
+        } else {
+            Ok(Value::none())
+        }
+    }
+}
+
+impl Format for Match {
+    fn format(&self, output: &mut String, indent_level: u8) {
+        output.push_str("match ");
+        self.matcher.format(output, indent_level);
+        output.push_str(" {");
+
+        for (expression, statement) in &self.options {
+            expression.format(output, indent_level);
+            output.push_str(" => ");
+            statement.format(output, indent_level);
+        }
+
+        if let Some(statement) = &self.fallback {
+            output.push_str("* => ");
+            statement.format(output, indent_level);
+        }
+
+        output.push('}');
+    }
+}

src/abstract_tree/match_pattern.rs

@@ -0,0 +1,64 @@
+use serde::{Deserialize, Serialize};
+use tree_sitter::Node as SyntaxNode;
+
+use crate::{
+    error::{RuntimeError, SyntaxError, ValidationError},
+    AbstractTree, Context, EnumPattern, Format, Type, Value, ValueNode,
+};
+
+#[derive(Debug, Clone, Serialize, Deserialize, Eq, PartialEq, PartialOrd, Ord)]
+pub enum MatchPattern {
+    EnumPattern(EnumPattern),
+    Value(ValueNode),
+    Wildcard,
+}
+
+impl AbstractTree for MatchPattern {
+    fn from_syntax(node: SyntaxNode, source: &str, context: &Context) -> Result<Self, SyntaxError> {
+        SyntaxError::expect_syntax_node("match_pattern", node)?;
+
+        let child = node.child(0).unwrap();
+        let pattern = match child.kind() {
+            "enum_pattern" => {
+                MatchPattern::EnumPattern(EnumPattern::from_syntax(child, source, context)?)
+            }
+            "value" => MatchPattern::Value(ValueNode::from_syntax(child, source, context)?),
+            "*" => MatchPattern::Wildcard,
+            _ => {
+                return Err(SyntaxError::UnexpectedSyntaxNode {
+                    expected: "enum pattern or value".to_string(),
+                    actual: child.kind().to_string(),
+                    position: node.range().into(),
+                })
+            }
+        };
+
+        Ok(pattern)
+    }
+
+    fn expected_type(&self, _context: &Context) -> Result<Type, ValidationError> {
+        match self {
+            MatchPattern::EnumPattern(enum_pattern) => enum_pattern.expected_type(_context),
+            MatchPattern::Value(value_node) => value_node.expected_type(_context),
+            MatchPattern::Wildcard => todo!(),
+        }
+    }
+
+    fn validate(&self, _source: &str, _context: &Context) -> Result<(), ValidationError> {
+        Ok(())
+    }
+
+    fn run(&self, _source: &str, _context: &Context) -> Result<Value, RuntimeError> {
+        match self {
+            MatchPattern::EnumPattern(enum_pattern) => enum_pattern.run(_source, _context),
+            MatchPattern::Value(value_node) => value_node.run(_source, _context),
+            MatchPattern::Wildcard => todo!(),
+        }
+    }
+}
+
+impl Format for MatchPattern {
+    fn format(&self, _output: &mut String, _indent_level: u8) {
+        todo!()
+    }
+}

src/abstract_tree/math.rs

@@ -0,0 +1,74 @@
+use serde::{Deserialize, Serialize};
+
+use crate::{
+    error::{RuntimeError, SyntaxError, ValidationError},
+    AbstractTree, Context, Expression, Format, MathOperator, SourcePosition, SyntaxNode, Type,
+    Value,
+};
+
+/// Abstract representation of a math operation.
+///
+/// Dust currently supports the four basic operations and the modulo (or
+/// remainder) operator.
+#[derive(Debug, Clone, Serialize, Deserialize, Eq, PartialEq, PartialOrd, Ord)]
+pub struct Math {
+    left: Expression,
+    operator: MathOperator,
+    right: Expression,
+    position: SourcePosition,
+}
+
+impl AbstractTree for Math {
+    fn from_syntax(node: SyntaxNode, source: &str, context: &Context) -> Result<Self, SyntaxError> {
+        SyntaxError::expect_syntax_node("math", node)?;
+
+        let left_node = node.child(0).unwrap();
+        let left = Expression::from_syntax(left_node, source, context)?;
+
+        let operator_node = node.child(1).unwrap();
+        let operator = MathOperator::from_syntax(operator_node, source, context)?;
+
+        let right_node = node.child(2).unwrap();
+        let right = Expression::from_syntax(right_node, source, context)?;
+
+        Ok(Math {
+            left,
+            operator,
+            right,
+            position: node.range().into(),
+        })
+    }
+
+    fn expected_type(&self, context: &Context) -> Result<Type, ValidationError> {
+        self.left.expected_type(context)
+    }
+
+    fn validate(&self, _source: &str, _context: &Context) -> Result<(), ValidationError> {
+        self.left.validate(_source, _context)?;
+        self.right.validate(_source, _context)
+    }
+
+    fn run(&self, source: &str, context: &Context) -> Result<Value, RuntimeError> {
+        let left = self.left.run(source, context)?;
+        let right = self.right.run(source, context)?;
+        let value = match self.operator {
+            MathOperator::Add => left.add(right, self.position)?,
+            MathOperator::Subtract => left.subtract(right, self.position)?,
+            MathOperator::Multiply => left.multiply(right, self.position)?,
+            MathOperator::Divide => left.divide(right, self.position)?,
+            MathOperator::Modulo => left.modulo(right, self.position)?,
+        };
+
+        Ok(value)
+    }
+}
+
+impl Format for Math {
+    fn format(&self, output: &mut String, indent_level: u8) {
+        self.left.format(output, indent_level);
+        output.push(' ');
+        self.operator.format(output, indent_level);
+        output.push(' ');
+        self.right.format(output, indent_level);
+    }
+}

src/abstract_tree/math_operator.rs

@@ -0,0 +1,69 @@
+use serde::{Deserialize, Serialize};
+
+use crate::{
+    error::{RuntimeError, SyntaxError, ValidationError},
+    AbstractTree, Context, Format, SyntaxNode, Type, Value,
+};
+
+#[derive(Debug, Clone, Serialize, Deserialize, Eq, PartialEq, PartialOrd, Ord)]
+pub enum MathOperator {
+    Add,
+    Subtract,
+    Multiply,
+    Divide,
+    Modulo,
+}
+
+impl AbstractTree for MathOperator {
+    fn from_syntax(
+        node: SyntaxNode,
+        _source: &str,
+        _context: &Context,
+    ) -> Result<Self, SyntaxError> {
+        SyntaxError::expect_syntax_node("math_operator", node)?;
+
+        let operator_node = node.child(0).unwrap();
+        let operator = match operator_node.kind() {
+            "+" => MathOperator::Add,
+            "-" => MathOperator::Subtract,
+            "*" => MathOperator::Multiply,
+            "/" => MathOperator::Divide,
+            "%" => MathOperator::Modulo,
+            _ => {
+                return Err(SyntaxError::UnexpectedSyntaxNode {
+                    expected: "+, -, *, / or %".to_string(),
+                    actual: operator_node.kind().to_string(),
+                    position: node.range().into(),
+                })
+            }
+        };
+
+        Ok(operator)
+    }
+
+    fn expected_type(&self, _context: &Context) -> Result<Type, ValidationError> {
+        Ok(Type::None)
+    }
+
+    fn validate(&self, _source: &str, _context: &Context) -> Result<(), ValidationError> {
+        Ok(())
+    }
+
+    fn run(&self, _source: &str, _context: &Context) -> Result<Value, RuntimeError> {
+        Ok(Value::none())
+    }
+}
+
+impl Format for MathOperator {
+    fn format(&self, output: &mut String, _indent_level: u8) {
+        let char = match self {
+            MathOperator::Add => '+',
+            MathOperator::Subtract => '-',
+            MathOperator::Multiply => '*',
+            MathOperator::Divide => '/',
+            MathOperator::Modulo => '%',
+        };
+
+        output.push(char);
+    }
+}

src/abstract_tree/mod.rs

@@ -0,0 +1,178 @@
+//! Abstract, executable representations of corresponding items found in Dust
+//! source code. The types that implement [AbstractTree] are inteded to be
+//! created by an [Interpreter].
+pub mod r#as;
+pub mod assignment;
+pub mod assignment_operator;
+pub mod block;
+pub mod command;
+pub mod enum_defintion;
+pub mod enum_pattern;
+pub mod expression;
+pub mod r#for;
+pub mod function_call;
+pub mod function_expression;
+pub mod function_node;
+pub mod identifier;
+pub mod if_else;
+pub mod index;
+pub mod index_assignment;
+pub mod index_expression;
+pub mod logic;
+pub mod logic_operator;
+pub mod map_node;
+pub mod r#match;
+pub mod match_pattern;
+pub mod math;
+pub mod math_operator;
+pub mod statement;
+pub mod struct_definition;
+pub mod r#type;
+pub mod type_definition;
+pub mod type_specification;
+pub mod value_node;
+pub mod r#while;
+
+pub use {
+    assignment::*, assignment_operator::*, block::*, command::*, enum_defintion::*,
+    enum_pattern::*, expression::*, function_call::*, function_expression::*, function_node::*,
+    identifier::*, if_else::*, index::*, index_assignment::IndexAssignment, index_expression::*,
+    logic::*, logic_operator::*, map_node::*, match_pattern::*, math::*, math_operator::*, r#as::*,
+    r#for::*, r#match::*, r#type::*, r#while::*, statement::*, struct_definition::*,
+    type_definition::*, type_specification::*, value_node::*,
+};
+
+use serde::{Deserialize, Serialize};
+
+use crate::{
+    context::Context,
+    error::{RuntimeError, SyntaxError, ValidationError},
+    SyntaxNode, Value,
+};
+
+/// A detailed report of a position in the source code string.
+#[derive(Clone, Copy, Debug, PartialEq, Eq, PartialOrd, Ord, Serialize, Deserialize)]
+pub struct SourcePosition {
+    pub start_byte: usize,
+    pub end_byte: usize,
+    pub start_row: usize,
+    pub start_column: usize,
+    pub end_row: usize,
+    pub end_column: usize,
+}
+
+impl From<tree_sitter::Range> for SourcePosition {
+    fn from(range: tree_sitter::Range) -> Self {
+        SourcePosition {
+            start_byte: range.start_byte,
+            end_byte: range.end_byte,
+            start_row: range.start_point.row + 1,
+            start_column: range.start_point.column,
+            end_row: range.end_point.row + 1,
+            end_column: range.end_point.column,
+        }
+    }
+}
+
+/// Abstraction that represents a whole, executable unit of dust code.
+#[derive(Clone, Debug, PartialEq, Eq, PartialOrd, Ord, Serialize, Deserialize)]
+pub struct Root {
+    statements: Vec<Statement>,
+}
+
+// TODO Change Root to use tree sitter's cursor to traverse the statements
+// instead of indexes. This will be more performant when there are a lot of
+// top-level statements in the tree.
+impl AbstractTree for Root {
+    fn from_syntax(node: SyntaxNode, source: &str, context: &Context) -> Result<Self, SyntaxError> {
+        SyntaxError::expect_syntax_node("root", node)?;
+
+        let statement_count = node.child_count();
+        let mut statements = Vec::with_capacity(statement_count);
+
+        for index in 0..statement_count {
+            let statement_node = node.child(index).unwrap();
+            let statement = Statement::from_syntax(statement_node, source, context)?;
+
+            statements.push(statement);
+        }
+
+        Ok(Root { statements })
+    }
+
+    fn validate(&self, _source: &str, _context: &Context) -> Result<(), ValidationError> {
+        for statement in &self.statements {
+            statement.validate(_source, _context)?;
+        }
+
+        Ok(())
+    }
+
+    fn run(&self, source: &str, context: &Context) -> Result<Value, RuntimeError> {
+        let mut value = Value::none();
+
+        for statement in &self.statements {
+            value = statement.run(source, context)?;
+
+            if statement.is_return() {
+                return Ok(value);
+            }
+        }
+
+        Ok(value)
+    }
+
+    fn expected_type(&self, context: &Context) -> Result<Type, ValidationError> {
+        self.statements.last().unwrap().expected_type(context)
+    }
+}
+
+impl Format for Root {
+    fn format(&self, output: &mut String, indent_level: u8) {
+        for (index, statement) in self.statements.iter().enumerate() {
+            if index > 0 {
+                output.push('\n');
+            }
+            statement.format(output, indent_level);
+            output.push('\n');
+        }
+    }
+}
+
+/// This trait is implemented by the Evaluator's internal types to form an
+/// executable tree that resolves to a single value.
+pub trait AbstractTree: Sized + Format {
+    /// Interpret the syntax tree at the given node and return the abstraction.
+    /// Returns a syntax error if the source is invalid.
+    ///
+    /// This function is used to convert nodes in the Tree Sitter concrete
+    /// syntax tree into executable nodes in an abstract tree. This function is
+    /// where the tree should be traversed by accessing sibling and child nodes.
+    /// Each node in the CST should be traversed only once.
+    ///
+    /// If necessary, the source code can be accessed directly by getting the
+    /// node's byte range.
+    fn from_syntax(node: SyntaxNode, source: &str, context: &Context) -> Result<Self, SyntaxError>;
+
+    /// Return the type of the value that this abstract node will create when
+    /// run. Returns a validation error if the tree is invalid.
+    fn expected_type(&self, context: &Context) -> Result<Type, ValidationError>;
+
+    /// Verify the type integrity of the node. Returns a validation error if the
+    /// tree is invalid.
+    fn validate(&self, source: &str, context: &Context) -> Result<(), ValidationError>;
+
+    /// Execute this node's logic and return a value. Returns a runtime error if
+    /// the node cannot resolve to a value.
+    fn run(&self, source: &str, context: &Context) -> Result<Value, RuntimeError>;
+}
+
+pub trait Format {
+    fn format(&self, output: &mut String, indent_level: u8);
+
+    fn indent(output: &mut String, indent_level: u8) {
+        for _ in 0..indent_level {
+            output.push_str("    ");
+        }
+    }
+}

src/abstract_tree/new.rs

@@ -0,0 +1,45 @@
+use serde::{Deserialize, Serialize};
+use tree_sitter::Node;
+
+use crate::{
+    error::{RuntimeError, SyntaxError, ValidationError},
+    AbstractTree, Context, Format, Identifier, Type, TypeSpecification, Value, ValueNode,
+};
+
+#[derive(Debug, Clone, Serialize, Deserialize, PartialEq, Eq, PartialOrd, Ord)]
+pub struct New {
+    identifier: Identifier,
+    properties: Vec<(Identifier, ValueNode, Option<TypeSpecification>)>,
+}
+
+impl AbstractTree for New {
+    fn from_syntax(node: Node, source: &str, context: &Context) -> Result<Self, SyntaxError> {
+        let identifier_node = node.child(1).unwrap();
+        let identifier = Identifier::from_syntax(identifier_node, source, context)?;
+
+        let properties = Vec::new();
+
+        Ok(New {
+            identifier,
+            properties,
+        })
+    }
+
+    fn expected_type(&self, _context: &Context) -> Result<Type, ValidationError> {
+        todo!()
+    }
+
+    fn validate(&self, _source: &str, _context: &Context) -> Result<(), ValidationError> {
+        todo!()
+    }
+
+    fn run(&self, _source: &str, _context: &Context) -> Result<Value, RuntimeError> {
+        todo!()
+    }
+}
+
+impl Format for New {
+    fn format(&self, _output: &mut String, _indent_level: u8) {
+        todo!()
+    }
+}

src/abstract_tree/statement.rs

@@ -0,0 +1,202 @@
+use serde::{Deserialize, Serialize};
+
+use crate::{
+    error::{RuntimeError, SyntaxError, ValidationError},
+    AbstractTree, Assignment, Block, Context, Expression, For, Format, IfElse, IndexAssignment,
+    Match, SyntaxNode, Type, TypeDefinition, Value, While,
+};
+
+/// Abstract representation of a statement.
+#[derive(Debug, Clone, Serialize, Deserialize, Eq, PartialEq, PartialOrd, Ord)]
+pub struct Statement {
+    is_return: bool,
+    statement_kind: StatementKind,
+}
+
+impl Statement {
+    pub fn is_return(&self) -> bool {
+        self.is_return
+    }
+}
+
+impl AbstractTree for Statement {
+    fn from_syntax(
+        node: SyntaxNode,
+        source: &str,
+        _context: &Context,
+    ) -> Result<Self, SyntaxError> {
+        SyntaxError::expect_syntax_node("statement", node)?;
+
+        let first_child = node.child(0).unwrap();
+        let mut is_return = first_child.kind() == "return" || first_child.kind() == "break";
+        let child = if is_return {
+            node.child(1).unwrap()
+        } else {
+            first_child
+        };
+
+        let statement_kind = StatementKind::from_syntax(child, source, _context)?;
+
+        if let StatementKind::Block(block) = &statement_kind {
+            if block.contains_return() {
+                is_return = true;
+            }
+        };
+
+        Ok(Statement {
+            is_return,
+            statement_kind,
+        })
+    }
+
+    fn expected_type(&self, _context: &Context) -> Result<Type, ValidationError> {
+        self.statement_kind.expected_type(_context)
+    }
+
+    fn validate(&self, _source: &str, _context: &Context) -> Result<(), ValidationError> {
+        self.statement_kind.validate(_source, _context)
+    }
+
+    fn run(&self, _source: &str, _context: &Context) -> Result<Value, RuntimeError> {
+        self.statement_kind.run(_source, _context)
+    }
+}
+
+impl Format for Statement {
+    fn format(&self, _output: &mut String, _indent_level: u8) {
+        self.statement_kind.format(_output, _indent_level)
+    }
+}
+
+#[derive(Debug, Clone, Serialize, Deserialize, Eq, PartialEq, PartialOrd, Ord)]
+enum StatementKind {
+    Assignment(Box<Assignment>),
+    Expression(Expression),
+    IfElse(Box<IfElse>),
+    Match(Match),
+    While(Box<While>),
+    Block(Box<Block>),
+    For(Box<For>),
+    IndexAssignment(Box<IndexAssignment>),
+    TypeDefinition(TypeDefinition),
+}
+
+impl AbstractTree for StatementKind {
+    fn from_syntax(node: SyntaxNode, source: &str, context: &Context) -> Result<Self, SyntaxError> {
+        SyntaxError::expect_syntax_node("statement_kind", node)?;
+
+        let child = node.child(0).unwrap();
+
+        match child.kind() {
+            "assignment" => Ok(StatementKind::Assignment(Box::new(
+                Assignment::from_syntax(child, source, context)?,
+            ))),
+            "expression" => Ok(StatementKind::Expression(Expression::from_syntax(
+                child, source, context,
+            )?)),
+            "if_else" => Ok(StatementKind::IfElse(Box::new(IfElse::from_syntax(
+                child, source, context,
+            )?))),
+            "while" => Ok(StatementKind::While(Box::new(While::from_syntax(
+                child, source, context,
+            )?))),
+            "block" => Ok(StatementKind::Block(Box::new(Block::from_syntax(
+                child, source, context,
+            )?))),
+            "for" => Ok(StatementKind::For(Box::new(For::from_syntax(
+                child, source, context,
+            )?))),
+            "index_assignment" => Ok(StatementKind::IndexAssignment(Box::new(
+                IndexAssignment::from_syntax(child, source, context)?,
+            ))),
+            "match" => Ok(StatementKind::Match(Match::from_syntax(
+                child, source, context,
+            )?)),
+            "type_definition" => Ok(StatementKind::TypeDefinition(TypeDefinition::from_syntax(
+                child, source, context
+            )?)),
+            _ => Err(SyntaxError::UnexpectedSyntaxNode {
+                expected:
+                    "assignment, index assignment, expression, type_definition, block, return, if...else, while, for or match".to_string(),
+                actual: child.kind().to_string(),
+                position: node.range().into(),
+            }),
+        }
+    }
+
+    fn expected_type(&self, _context: &Context) -> Result<Type, ValidationError> {
+        match self {
+            StatementKind::Assignment(assignment) => assignment.expected_type(_context),
+            StatementKind::Expression(expression) => expression.expected_type(_context),
+            StatementKind::IfElse(if_else) => if_else.expected_type(_context),
+            StatementKind::Match(r#match) => r#match.expected_type(_context),
+            StatementKind::While(r#while) => r#while.expected_type(_context),
+            StatementKind::Block(block) => block.expected_type(_context),
+            StatementKind::For(r#for) => r#for.expected_type(_context),
+            StatementKind::IndexAssignment(index_assignment) => {
+                index_assignment.expected_type(_context)
+            }
+            StatementKind::TypeDefinition(type_definition) => {
+                type_definition.expected_type(_context)
+            }
+        }
+    }
+
+    fn validate(&self, _source: &str, _context: &Context) -> Result<(), ValidationError> {
+        match self {
+            StatementKind::Assignment(assignment) => assignment.validate(_source, _context),
+            StatementKind::Expression(expression) => expression.validate(_source, _context),
+            StatementKind::IfElse(if_else) => if_else.validate(_source, _context),
+            StatementKind::Match(r#match) => r#match.validate(_source, _context),
+            StatementKind::While(r#while) => r#while.validate(_source, _context),
+            StatementKind::Block(block) => block.validate(_source, _context),
+            StatementKind::For(r#for) => r#for.validate(_source, _context),
+            StatementKind::IndexAssignment(index_assignment) => {
+                index_assignment.validate(_source, _context)
+            }
+            StatementKind::TypeDefinition(type_definition) => {
+                type_definition.validate(_source, _context)
+            }
+        }
+    }
+
+    fn run(&self, _source: &str, _context: &Context) -> Result<Value, RuntimeError> {
+        match self {
+            StatementKind::Assignment(assignment) => assignment.run(_source, _context),
+            StatementKind::Expression(expression) => expression.run(_source, _context),
+            StatementKind::IfElse(if_else) => if_else.run(_source, _context),
+            StatementKind::Match(r#match) => r#match.run(_source, _context),
+            StatementKind::While(r#while) => r#while.run(_source, _context),
+            StatementKind::Block(block) => block.run(_source, _context),
+            StatementKind::For(r#for) => r#for.run(_source, _context),
+            StatementKind::IndexAssignment(index_assignment) => {
+                index_assignment.run(_source, _context)
+            }
+            StatementKind::TypeDefinition(type_definition) => {
+                type_definition.run(_source, _context)
+            }
+        }
+    }
+}
+
+impl Format for StatementKind {
+    fn format(&self, output: &mut String, indent_level: u8) {
+        StatementKind::indent(output, indent_level);
+
+        match self {
+            StatementKind::Assignment(assignment) => assignment.format(output, indent_level),
+            StatementKind::Expression(expression) => expression.format(output, indent_level),
+            StatementKind::IfElse(if_else) => if_else.format(output, indent_level),
+            StatementKind::Match(r#match) => r#match.format(output, indent_level),
+            StatementKind::While(r#while) => r#while.format(output, indent_level),
+            StatementKind::Block(block) => block.format(output, indent_level),
+            StatementKind::For(r#for) => r#for.format(output, indent_level),
+            StatementKind::IndexAssignment(index_assignment) => {
+                index_assignment.format(output, indent_level)
+            }
+            StatementKind::TypeDefinition(type_definition) => {
+                type_definition.format(output, indent_level)
+            }
+        }
+    }
+}

src/abstract_tree/struct_definition.rs

@@ -0,0 +1,120 @@
+use std::collections::BTreeMap;
+
+use serde::{Deserialize, Serialize};
+use tree_sitter::Node as SyntaxNode;
+
+use crate::{
+    error::{RuntimeError, SyntaxError, ValidationError},
+    AbstractTree, Context, Format, Identifier, Map, MapNode, Statement, StructInstance, Type,
+    TypeDefinition, TypeSpecification, Value,
+};
+
+#[derive(Debug, Clone, Serialize, Deserialize, Eq, PartialEq, PartialOrd, Ord)]
+pub struct StructDefinition {
+    name: Identifier,
+    properties: BTreeMap<Identifier, (Option<Statement>, Type)>,
+}
+
+impl StructDefinition {
+    pub fn instantiate(
+        &self,
+        new_properties: &MapNode,
+        source: &str,
+        context: &Context,
+    ) -> Result<StructInstance, RuntimeError> {
+        let mut all_properties = Map::new();
+
+        for (key, (statement_option, _)) in &self.properties {
+            if let Some(statement) = statement_option {
+                let value = statement.run(source, context)?;
+
+                all_properties.set(key.clone(), value);
+            }
+        }
+
+        for (key, (statement, _)) in new_properties.properties() {
+            let value = statement.run(source, context)?;
+
+            all_properties.set(key.clone(), value);
+        }
+
+        Ok(StructInstance::new(self.name.clone(), all_properties))
+    }
+}
+
+impl AbstractTree for StructDefinition {
+    fn from_syntax(node: SyntaxNode, source: &str, context: &Context) -> Result<Self, SyntaxError> {
+        SyntaxError::expect_syntax_node("struct_definition", node)?;
+
+        let name_node = node.child(1).unwrap();
+        let name = Identifier::from_syntax(name_node, source, context)?;
+
+        let mut properties = BTreeMap::new();
+        let mut current_identifier: Option<Identifier> = None;
+        let mut current_type: Option<Type> = None;
+        let mut current_statement = None;
+
+        for index in 2..node.child_count() - 1 {
+            let child_syntax_node = node.child(index).unwrap();
+
+            if child_syntax_node.kind() == "identifier" {
+                if current_statement.is_none() {
+                    if let (Some(identifier), Some(r#type)) = (&current_identifier, &current_type) {
+                        properties.insert(identifier.clone(), (None, r#type.clone()));
+                    }
+                }
+
+                current_type = None;
+                current_identifier =
+                    Some(Identifier::from_syntax(child_syntax_node, source, context)?);
+            }
+
+            if child_syntax_node.kind() == "type_specification" {
+                current_type = Some(
+                    TypeSpecification::from_syntax(child_syntax_node, source, context)?
+                        .take_inner(),
+                );
+            }
+
+            if child_syntax_node.kind() == "statement" {
+                current_statement =
+                    Some(Statement::from_syntax(child_syntax_node, source, context)?);
+
+                if let Some(identifier) = &current_identifier {
+                    let r#type = if let Some(r#type) = &current_type {
+                        r#type.clone()
+                    } else {
+                        Type::None
+                    };
+
+                    properties.insert(
+                        identifier.clone(),
+                        (current_statement.clone(), r#type.clone()),
+                    );
+                }
+            }
+        }
+
+        Ok(StructDefinition { name, properties })
+    }
+
+    fn expected_type(&self, _context: &Context) -> Result<Type, ValidationError> {
+        Ok(Type::None)
+    }
+
+    fn validate(&self, _source: &str, _context: &Context) -> Result<(), ValidationError> {
+        Ok(())
+    }
+
+    fn run(&self, _source: &str, context: &Context) -> Result<Value, RuntimeError> {
+        context.set_definition(self.name.clone(), TypeDefinition::Struct(self.clone()))?;
+
+        Ok(Value::none())
+    }
+}
+
+impl Format for StructDefinition {
+    fn format(&self, _output: &mut String, _indent_level: u8) {
+        todo!()
+    }
+}

src/abstract_tree/type.rs

@@ -0,0 +1,394 @@
+use std::{
+    collections::BTreeMap,
+    fmt::{self, Display, Formatter},
+};
+
+use serde::{Deserialize, Serialize};
+use tree_sitter::Node as SyntaxNode;
+
+use crate::{
+    built_in_types::BuiltInType,
+    error::{RuntimeError, SyntaxError, ValidationError},
+    AbstractTree, Context, Format, Identifier, TypeSpecification, Value,
+};
+
+#[derive(Debug, Clone, Serialize, Deserialize, Eq, PartialEq, PartialOrd, Ord)]
+pub enum Type {
+    Any,
+    Boolean,
+    Collection,
+    Custom {
+        name: Identifier,
+        arguments: Vec<Type>,
+    },
+    Float,
+    Function {
+        parameter_types: Vec<Type>,
+        return_type: Box<Type>,
+    },
+    Integer,
+    List,
+    ListOf(Box<Type>),
+    ListExact(Vec<Type>),
+    Map(Option<BTreeMap<Identifier, Type>>),
+    None,
+    Number,
+    String,
+    Range,
+}
+
+impl Type {
+    pub fn custom(name: Identifier, arguments: Vec<Type>) -> Self {
+        Type::Custom { name, arguments }
+    }
+
+    pub fn option(inner_type: Option<Type>) -> Self {
+        BuiltInType::Option(inner_type).get().clone()
+    }
+
+    pub fn list(item_type: Type) -> Self {
+        Type::ListOf(Box::new(item_type))
+    }
+
+    pub fn function(parameter_types: Vec<Type>, return_type: Type) -> Self {
+        Type::Function {
+            parameter_types,
+            return_type: Box::new(return_type),
+        }
+    }
+
+    /// Returns a boolean indicating whether is type is accepting of the other.
+    ///
+    /// The types do not need to match exactly. For example, the Any variant matches all of the
+    /// others and the Number variant accepts Number, Integer and Float.
+    pub fn accepts(&self, other: &Type) -> bool {
+        log::info!("Checking type {self} against {other}.");
+
+        match (self, other) {
+            (Type::Any, _)
+            | (_, Type::Any)
+            | (Type::Boolean, Type::Boolean)
+            | (Type::Collection, Type::Collection)
+            | (Type::Collection, Type::String)
+            | (Type::Collection, Type::List)
+            | (Type::List, Type::Collection)
+            | (Type::Collection, Type::ListExact(_))
+            | (Type::ListExact(_), Type::Collection)
+            | (Type::Collection, Type::ListOf(_))
+            | (Type::ListOf(_), Type::Collection)
+            | (Type::Collection, Type::Map(_))
+            | (Type::Map(_), Type::Collection)
+            | (Type::String, Type::Collection)
+            | (Type::Float, Type::Float)
+            | (Type::Integer, Type::Integer)
+            | (Type::List, Type::List)
+            | (Type::Map(None), Type::Map(None))
+            | (Type::Number, Type::Number)
+            | (Type::Number, Type::Integer)
+            | (Type::Number, Type::Float)
+            | (Type::Integer, Type::Number)
+            | (Type::Float, Type::Number)
+            | (Type::String, Type::String)
+            | (Type::None, Type::None) => true,
+            (Type::Map(left_types), Type::Map(right_types)) => left_types == right_types,
+            (
+                Type::Custom {
+                    name: left_name,
+                    arguments: left_arguments,
+                },
+                Type::Custom {
+                    name: right_name,
+                    arguments: right_arguments,
+                },
+            ) => left_name == right_name && left_arguments == right_arguments,
+            (Type::ListOf(self_item_type), Type::ListOf(other_item_type)) => {
+                self_item_type.accepts(&other_item_type)
+            }
+            (Type::ListExact(self_types), Type::ListExact(other_types)) => {
+                for (left, right) in self_types.iter().zip(other_types.iter()) {
+                    if !left.accepts(right) {
+                        return false;
+                    }
+                }
+
+                true
+            }
+            (Type::ListExact(exact_types), Type::ListOf(of_type))
+            | (Type::ListOf(of_type), Type::ListExact(exact_types)) => {
+                exact_types.iter().all(|r#type| r#type == of_type.as_ref())
+            }
+            (
+                Type::Function {
+                    parameter_types: self_parameter_types,
+                    return_type: self_return_type,
+                },
+                Type::Function {
+                    parameter_types: other_parameter_types,
+                    return_type: other_return_type,
+                },
+            ) => {
+                let parameter_type_pairs = self_parameter_types
+                    .iter()
+                    .zip(other_parameter_types.iter());
+
+                for (self_parameter_type, other_parameter_type) in parameter_type_pairs {
+                    if self_parameter_type == other_parameter_type {
+                        return false;
+                    }
+                }
+
+                self_return_type == other_return_type
+            }
+            _ => false,
+        }
+    }
+
+    pub fn is_function(&self) -> bool {
+        matches!(self, Type::Function { .. })
+    }
+
+    pub fn is_list(&self) -> bool {
+        matches!(self, Type::ListOf(_))
+    }
+
+    pub fn is_map(&self) -> bool {
+        matches!(self, Type::Map(_))
+    }
+}
+
+impl AbstractTree for Type {
+    fn from_syntax(
+        node: SyntaxNode,
+        _source: &str,
+        context: &Context,
+    ) -> Result<Self, SyntaxError> {
+        SyntaxError::expect_syntax_node("type", node)?;
+
+        let type_node = node.child(0).unwrap();
+
+        let r#type = match type_node.kind() {
+            "identifier" => {
+                let name = Identifier::from_syntax(type_node, _source, context)?;
+                let mut arguments = Vec::new();
+
+                for index in 2..node.child_count() - 1 {
+                    let child = node.child(index).unwrap();
+
+                    if child.is_named() {
+                        let r#type = Type::from_syntax(child, _source, context)?;
+
+                        arguments.push(r#type);
+                    }
+                }
+
+                Type::custom(name, arguments)
+            }
+            "{" => {
+                let mut type_map = BTreeMap::new();
+                let mut previous_identifier = None;
+
+                for index in 1..node.child_count() - 1 {
+                    let child = node.child(index).unwrap();
+
+                    if let Some(identifier) = previous_identifier {
+                        let type_specification =
+                            TypeSpecification::from_syntax(child, _source, context)?;
+
+                        type_map.insert(identifier, type_specification.take_inner());
+                        previous_identifier = None;
+                    } else {
+                        previous_identifier =
+                            Some(Identifier::from_syntax(child, _source, context)?)
+                    }
+                }
+
+                Type::Map(Some(type_map))
+            }
+            "[" => {
+                let item_type_node = node.child(1).unwrap();
+                let item_type = Type::from_syntax(item_type_node, _source, context)?;
+
+                Type::ListOf(Box::new(item_type))
+            }
+            "list" => {
+                let item_type_node = node.child(1);
+
+                if let Some(child) = item_type_node {
+                    Type::ListOf(Box::new(Type::from_syntax(child, _source, context)?))
+                } else {
+                    Type::List
+                }
+            }
+            "any" => Type::Any,
+            "bool" => Type::Boolean,
+            "collection" => Type::Collection,
+            "float" => Type::Float,
+            "(" => {
+                let child_count = node.child_count();
+                let mut parameter_types = Vec::new();
+
+                for index in 1..child_count - 2 {
+                    let child = node.child(index).unwrap();
+
+                    if child.is_named() {
+                        let parameter_type = Type::from_syntax(child, _source, context)?;
+
+                        parameter_types.push(parameter_type);
+                    }
+                }
+
+                let final_node = node.child(child_count - 1).unwrap();
+                let return_type = if final_node.is_named() {
+                    Type::from_syntax(final_node, _source, context)?
+                } else {
+                    Type::option(None)
+                };
+
+                Type::Function {
+                    parameter_types,
+                    return_type: Box::new(return_type),
+                }
+            }
+            "int" => Type::Integer,
+            "map" => Type::Map(None),
+            "num" => Type::Number,
+            "none" => Type::None,
+            "str" => Type::String,
+            _ => {
+                return Err(SyntaxError::UnexpectedSyntaxNode {
+                    expected: "any, bool, float, int, num, str, list, map, custom type, (, [ or {"
+                        .to_string(),
+                    actual: type_node.kind().to_string(),
+                    position: node.range().into(),
+                })
+            }
+        };
+
+        Ok(r#type)
+    }
+
+    fn expected_type(&self, _context: &Context) -> Result<Type, ValidationError> {
+        Ok(Type::None)
+    }
+
+    fn validate(&self, _source: &str, _context: &Context) -> Result<(), ValidationError> {
+        Ok(())
+    }
+
+    fn run(&self, _source: &str, _context: &Context) -> Result<Value, RuntimeError> {
+        Ok(Value::none())
+    }
+}
+
+impl Format for Type {
+    fn format(&self, output: &mut String, indent_level: u8) {
+        match self {
+            Type::Any => output.push_str("any"),
+            Type::Boolean => output.push_str("bool"),
+            Type::Collection => output.push_str("collection"),
+            Type::Custom {
+                name: _,
+                arguments: _,
+            } => todo!(),
+            Type::Float => output.push_str("float"),
+            Type::Function {
+                parameter_types,
+                return_type,
+            } => {
+                output.push('(');
+
+                for (index, parameter_type) in parameter_types.iter().enumerate() {
+                    parameter_type.format(output, indent_level);
+
+                    if index != parameter_types.len() - 1 {
+                        output.push(' ');
+                    }
+                }
+
+                output.push_str(") -> ");
+                return_type.format(output, indent_level);
+            }
+            Type::Integer => output.push_str("int"),
+            Type::List => todo!(),
+            Type::ListOf(item_type) => {
+                output.push('[');
+                item_type.format(output, indent_level);
+                output.push(']');
+            }
+            Type::ListExact(_) => todo!(),
+            Type::Map(_) => {
+                output.push_str("map");
+            }
+            Type::None => output.push_str("Option::None"),
+            Type::Number => output.push_str("num"),
+            Type::String => output.push_str("str"),
+            Type::Range => todo!(),
+        }
+    }
+}
+
+impl Display for Type {
+    fn fmt(&self, f: &mut Formatter) -> fmt::Result {
+        match self {
+            Type::Any => write!(f, "any"),
+            Type::Boolean => write!(f, "bool"),
+            Type::Collection => write!(f, "collection"),
+            Type::Custom { name, arguments } => {
+                if !arguments.is_empty() {
+                    write!(f, "<")?;
+
+                    for (index, r#type) in arguments.into_iter().enumerate() {
+                        if index == arguments.len() - 1 {
+                            write!(f, "{}", r#type)?;
+                        } else {
+                            write!(f, "{}, ", r#type)?;
+                        }
+                    }
+
+                    write!(f, ">")
+                } else {
+                    write!(f, "{name}")
+                }
+            }
+            Type::Float => write!(f, "float"),
+            Type::Function {
+                parameter_types,
+                return_type,
+            } => {
+                write!(f, "(")?;
+
+                for (index, parameter_type) in parameter_types.iter().enumerate() {
+                    write!(f, "{parameter_type}")?;
+
+                    if index != parameter_types.len() - 1 {
+                        write!(f, " ")?;
+                    }
+                }
+
+                write!(f, ")")?;
+                write!(f, " -> {return_type}")
+            }
+            Type::Integer => write!(f, "int"),
+            Type::List => write!(f, "list"),
+            Type::ListOf(item_type) => write!(f, "[{item_type}]"),
+            Type::ListExact(types) => {
+                write!(f, "[")?;
+
+                for (index, r#type) in types.into_iter().enumerate() {
+                    if index == types.len() - 1 {
+                        write!(f, "{}", r#type)?;
+                    } else {
+                        write!(f, "{}, ", r#type)?;
+                    }
+                }
+
+                write!(f, "]")
+            }
+            Type::Map(_) => write!(f, "map"),
+            Type::Number => write!(f, "num"),
+            Type::None => write!(f, "none"),
+            Type::String => write!(f, "str"),
+            Type::Range => todo!(),
+        }
+    }
+}

src/abstract_tree/type_definition.rs

@@ -0,0 +1,73 @@
+use serde::{Deserialize, Serialize};
+use tree_sitter::Node as SyntaxNode;
+
+use crate::{
+    error::{RuntimeError, SyntaxError, ValidationError},
+    AbstractTree, Context, EnumDefinition, Format, Identifier, StructDefinition, Type, Value,
+};
+
+#[derive(Debug, Clone, Serialize, Deserialize, Eq, PartialEq, PartialOrd, Ord)]
+pub enum TypeDefinition {
+    Enum(EnumDefinition),
+    Struct(StructDefinition),
+}
+
+impl TypeDefinition {
+    pub fn identifier(&self) -> &Identifier {
+        match self {
+            TypeDefinition::Enum(enum_definition) => enum_definition.identifier(),
+            TypeDefinition::Struct(_) => todo!(),
+        }
+    }
+}
+
+impl AbstractTree for TypeDefinition {
+    fn from_syntax(node: SyntaxNode, source: &str, context: &Context) -> Result<Self, SyntaxError> {
+        SyntaxError::expect_syntax_node("type_definition", node)?;
+
+        let child = node.child(0).unwrap();
+
+        match child.kind() {
+            "enum_definition" => Ok(TypeDefinition::Enum(EnumDefinition::from_syntax(
+                child, source, context,
+            )?)),
+            "struct_definition" => Ok(TypeDefinition::Struct(StructDefinition::from_syntax(
+                child, source, context,
+            )?)),
+            _ => Err(SyntaxError::UnexpectedSyntaxNode {
+                expected: "enum or struct definition".to_string(),
+                actual: child.kind().to_string(),
+                position: node.range().into(),
+            }),
+        }
+    }
+
+    fn expected_type(&self, _context: &Context) -> Result<Type, ValidationError> {
+        match self {
+            TypeDefinition::Enum(enum_definition) => enum_definition.expected_type(_context),
+            TypeDefinition::Struct(struct_definition) => struct_definition.expected_type(_context),
+        }
+    }
+
+    fn validate(&self, _source: &str, _context: &Context) -> Result<(), ValidationError> {
+        match self {
+            TypeDefinition::Enum(enum_definition) => enum_definition.validate(_source, _context),
+            TypeDefinition::Struct(struct_definition) => {
+                struct_definition.validate(_source, _context)
+            }
+        }
+    }
+
+    fn run(&self, _source: &str, _context: &Context) -> Result<Value, RuntimeError> {
+        match self {
+            TypeDefinition::Enum(enum_definition) => enum_definition.run(_source, _context),
+            TypeDefinition::Struct(struct_definition) => struct_definition.run(_source, _context),
+        }
+    }
+}
+
+impl Format for TypeDefinition {
+    fn format(&self, _output: &mut String, _indent_level: u8) {
+        todo!()
+    }
+}

src/abstract_tree/type_specification.rs

@@ -0,0 +1,56 @@
+use serde::{Deserialize, Serialize};
+
+use crate::{
+    error::{RuntimeError, SyntaxError, ValidationError},
+    AbstractTree, Context, Format, SyntaxNode, Type, Value,
+};
+
+#[derive(Debug, Clone, Serialize, Deserialize, Eq, PartialEq, PartialOrd, Ord)]
+pub struct TypeSpecification {
+    r#type: Type,
+}
+
+impl TypeSpecification {
+    pub fn new(r#type: Type) -> Self {
+        Self { r#type }
+    }
+
+    pub fn inner(&self) -> &Type {
+        &self.r#type
+    }
+
+    pub fn take_inner(self) -> Type {
+        self.r#type
+    }
+}
+
+impl AbstractTree for TypeSpecification {
+    fn from_syntax(node: SyntaxNode, source: &str, context: &Context) -> Result<Self, SyntaxError> {
+        SyntaxError::expect_syntax_node("type_specification", node)?;
+
+        let type_node = node.child(1).unwrap();
+        let r#type = Type::from_syntax(type_node, source, context)?;
+
+        Ok(TypeSpecification { r#type })
+    }
+
+    fn expected_type(&self, context: &Context) -> Result<Type, ValidationError> {
+        self.r#type.expected_type(context)
+    }
+
+    fn validate(&self, _source: &str, _context: &Context) -> Result<(), ValidationError> {
+        Ok(())
+    }
+
+    fn run(&self, source: &str, context: &Context) -> Result<Value, RuntimeError> {
+        self.r#type.run(source, context)
+    }
+}
+
+impl Format for TypeSpecification {
+    fn format(&self, output: &mut String, indent_level: u8) {
+        output.push('<');
+        self.r#type.format(output, indent_level);
+        output.push('>');
+    }
+}

src/abstract_tree/value_node.rs

@@ -0,0 +1,357 @@
+use std::{cmp::Ordering, ops::RangeInclusive};
+
+use serde::{Deserialize, Serialize};
+use tree_sitter::Node as SyntaxNode;
+
+use crate::{
+    error::{RuntimeError, SyntaxError, ValidationError},
+    AbstractTree, Context, Expression, Format, Function, FunctionNode,
+    Identifier, List, Type, Value, TypeDefinition, MapNode,
+};
+
+#[derive(Debug, Clone, Serialize, Deserialize, Eq, PartialEq)]
+pub enum ValueNode {
+    Boolean(String),
+    Float(String),
+    Function(Function),
+    Integer(String),
+    String(String),
+    List(Vec<Expression>),
+    Map(MapNode),
+    Range(RangeInclusive<i64>),
+    Struct {
+        name: Identifier,
+        properties: MapNode,
+    },
+    Enum {
+        name: Identifier,
+        variant: Identifier,
+        expression: Option<Box<Expression>>,
+    },
+}
+
+impl AbstractTree for ValueNode {
+    fn from_syntax(node: SyntaxNode, source: &str, context: &Context) -> Result<Self, SyntaxError> {
+        SyntaxError::expect_syntax_node("value", node)?;
+
+        let child = node.child(0).unwrap();
+        let value_node = match child.kind() {
+            "boolean" => ValueNode::Boolean(source[child.byte_range()].to_string()),
+            "float" => ValueNode::Float(source[child.byte_range()].to_string()),
+            "function" => {
+                let function_node = FunctionNode::from_syntax(child, source, context)?;
+
+                ValueNode::Function(Function::ContextDefined(function_node))
+            }
+            "integer" => ValueNode::Integer(source[child.byte_range()].to_string()),
+            "string" => {
+                let without_quotes = child.start_byte() + 1..child.end_byte() - 1;
+
+                ValueNode::String(source[without_quotes].to_string())
+            }
+            "list" => {
+                let mut expressions = Vec::new();
+
+                for index in 1..child.child_count() - 1 {
+                    let current_node = child.child(index).unwrap();
+
+                    if current_node.is_named() {
+                        let expression = Expression::from_syntax(current_node, source, context)?;
+
+                        expressions.push(expression);
+                    }
+                }
+
+                ValueNode::List(expressions)
+            }
+            "map" => {
+                ValueNode::Map(MapNode::from_syntax(child, source, context)?)
+            }
+            "range" => {
+                let mut split = source[child.byte_range()].split("..");
+                let start = split.next().unwrap().parse().unwrap();
+                let end = split.next().unwrap().parse().unwrap();
+
+                ValueNode::Range(start..=end)
+            }
+            "enum_instance" => {
+                let name_node = child.child(0).unwrap();
+                let name = Identifier::from_syntax(name_node, source, context)?;
+                
+                let variant_node = child.child(2).unwrap();
+                let variant = Identifier::from_syntax(variant_node, source, context)?;
+             
+                let expression = if let Some(expression_node) = child.child(4) {                
+                    Some(Box::new(Expression::from_syntax(expression_node, source, context)?))
+                } else {
+                    None
+                };
+
+                ValueNode::Enum { name, variant , expression  }                
+            }
+            "struct_instance" => {
+                let name_node = child.child(0).unwrap();
+                let name = Identifier::from_syntax(name_node, source, context)?;
+
+                let properties_node = child.child(2).unwrap();
+                let properties = MapNode::from_syntax(properties_node, source, context)?;
+
+                ValueNode::Struct
+                {
+                    name,
+                    properties
+                }
+            }
+            _ => {
+                return Err(SyntaxError::UnexpectedSyntaxNode {
+                    expected:
+                        "string, integer, float, boolean, range, list, map, option, function, struct or enum"
+                            .to_string(),
+                    actual: child.kind().to_string(),
+                    position: node.range().into(),
+                })
+            }
+        };
+
+        Ok(value_node)
+    }
+
+    fn expected_type(&self, context: &Context) -> Result<Type, ValidationError> {
+        let r#type = match self {
+            ValueNode::Boolean(_) => Type::Boolean,
+            ValueNode::Float(_) => Type::Float,
+            ValueNode::Function(function) => function.r#type(),
+            ValueNode::Integer(_) => Type::Integer,
+            ValueNode::String(_) => Type::String,
+            ValueNode::List(expressions) => {
+                let mut item_types = Vec::new();
+
+                for expression in expressions {
+                    let expression_type = expression.expected_type(context)?;
+
+                    item_types.push(expression_type);
+                }
+
+                Type::ListExact(item_types)
+            }
+            ValueNode::Map(map_node) => map_node.expected_type(context)?,
+            ValueNode::Struct { name, .. }  => {
+                Type::custom(name.clone(), Vec::with_capacity(0))
+            }
+            ValueNode::Range(_) => Type::Range,
+            ValueNode::Enum { name, variant, expression: _ } => {
+                let types: Vec<Type> = if let Some(type_definition) = context.get_definition(name)? {
+                    if let TypeDefinition::Enum(enum_definition) = type_definition {
+                        let types = enum_definition.variants().into_iter().find_map(|(identifier, types)| {
+                            if identifier == variant {
+                                Some(types.clone())
+                            } else {
+                                None
+                            }
+                        });
+
+                        if let Some(types) = types {
+                            types 
+                        } else {
+                            return Err(ValidationError::VariableIdentifierNotFound(variant.clone()));
+                        }
+                         
+                    } else {
+                        return Err(ValidationError::ExpectedEnumDefintion { actual: type_definition.clone() });
+                    }
+                } else {
+                     return Err(ValidationError::VariableIdentifierNotFound(name.clone()));
+                };
+
+                Type::custom(name.clone(), types.clone())
+                
+            },
+        };
+
+        Ok(r#type)
+    }
+
+    fn validate(&self, _source: &str, context: &Context) -> Result<(), ValidationError> {
+        match self {
+            ValueNode::Function(function) => {
+                if let Function::ContextDefined(function_node) = function {
+                    function_node.validate(_source, context)?;
+                }
+            }
+            ValueNode::Map(map_node) => map_node.validate(_source, context)?,
+            ValueNode::Enum { name, expression, .. } => {
+                name.validate(_source, context)?;
+
+                if let Some(expression) = expression {
+                    expression.validate(_source, context)?;
+                }
+            }
+            _ => {},
+        }
+
+        Ok(())
+    }
+
+    fn run(&self, source: &str, context: &Context) -> Result<Value, RuntimeError> {
+        let value = match self {
+            ValueNode::Boolean(value_source) => Value::Boolean(value_source.parse().unwrap()),
+            ValueNode::Float(value_source) => {
+                let float = value_source.parse()?;
+
+                Value::Float(float)
+            }
+            ValueNode::Function(function) => Value::Function(function.clone()),
+            ValueNode::Integer(value_source) => Value::Integer(value_source.parse().unwrap()),
+            ValueNode::String(value_source) => Value::string(value_source.clone()),
+            ValueNode::List(expressions) => {
+                let mut values = Vec::with_capacity(expressions.len());
+
+                for node in expressions {
+                    let value = node.run(source, context)?;
+
+                    values.push(value);
+                }
+
+                Value::List(List::with_items(values))
+            }
+            ValueNode::Map(map_node) => map_node.run(source, context)?,
+            ValueNode::Range(range) => Value::Range(range.clone()),
+            ValueNode::Struct { name, properties } => {
+                let instance = if let Some(definition) = context.get_definition(name)? {
+                    if let TypeDefinition::Struct(struct_definition) = definition {
+                        struct_definition.instantiate(properties, source, context)?
+                    } else {
+                        return Err(RuntimeError::ValidationFailure(ValidationError::ExpectedStructDefintion { actual: definition.clone() }))
+                    }
+                } else {
+                    return Err(RuntimeError::ValidationFailure(
+                        ValidationError::TypeDefinitionNotFound(name.clone())
+                    ));
+                };
+
+                Value::Struct(instance)
+
+            }
+            ValueNode::Enum { name, variant, expression } => {
+                let value = if let Some(expression) = expression {
+                    expression.run(source, context)?
+                } else {
+                    Value::none()
+                };
+                let instance = if let Some(definition) = context.get_definition(name)? {
+                    if let TypeDefinition::Enum(enum_defintion) = definition {
+                        enum_defintion.instantiate(variant.clone(), Some(value))
+                    } else {
+                        return Err(RuntimeError::ValidationFailure(
+                            ValidationError::ExpectedEnumDefintion {
+                                actual: definition.clone()
+                            }
+                        ));
+                    }
+                } else {
+                    return Err(RuntimeError::ValidationFailure(
+                        ValidationError::TypeDefinitionNotFound(name.clone())
+                    ));
+                };
+
+                Value::Enum(instance)                
+            },
+        };
+
+        Ok(value)
+    }
+}
+
+impl Format for ValueNode {
+    fn format(&self, output: &mut String, indent_level: u8) {
+        match self {
+            ValueNode::Boolean(source) | ValueNode::Float(source) | ValueNode::Integer(source) => {
+                output.push_str(source)
+            }
+            ValueNode::String(source) => {
+                output.push('\'');
+                output.push_str(source);
+                output.push('\'');
+            }
+            ValueNode::Function(function) => function.format(output, indent_level),
+            ValueNode::List(expressions) => {
+                output.push('[');
+
+                for expression in expressions {
+                    expression.format(output, indent_level);
+                }
+
+                output.push(']');
+            }
+            ValueNode::Map(map_node) => map_node.format(output, indent_level),
+            ValueNode::Struct { name, properties } => {
+                name.format(output, indent_level);
+                properties.format(output, indent_level);
+            }
+            ValueNode::Range(_) => todo!(),
+            ValueNode::Enum { ..  } => todo!(),
+        }
+    }
+}
+
+impl Ord for ValueNode {
+    fn cmp(&self, other: &Self) -> std::cmp::Ordering {
+        match (self, other) {
+            (ValueNode::Boolean(left), ValueNode::Boolean(right)) => left.cmp(right),
+            (ValueNode::Boolean(_), _) => Ordering::Greater,
+            (ValueNode::Float(left), ValueNode::Float(right)) => left.cmp(right),
+            (ValueNode::Float(_), _) => Ordering::Greater,
+            (ValueNode::Function(left), ValueNode::Function(right)) => left.cmp(right),
+            (ValueNode::Function(_), _) => Ordering::Greater,
+            (ValueNode::Integer(left), ValueNode::Integer(right)) => left.cmp(right),
+            (ValueNode::Integer(_), _) => Ordering::Greater,
+            (ValueNode::String(left), ValueNode::String(right)) => left.cmp(right),
+            (ValueNode::String(_), _) => Ordering::Greater,
+            (ValueNode::List(left), ValueNode::List(right)) => left.cmp(right),
+            (ValueNode::List(_), _) => Ordering::Greater,
+            (ValueNode::Map(left), ValueNode::Map(right)) => left.cmp(right),
+            (ValueNode::Map(_), _) => Ordering::Greater,
+            (ValueNode::Struct{ name: left_name, properties: left_properties }, ValueNode::Struct {name: right_name, properties: right_properties} ) => {
+                let name_cmp = left_name.cmp(right_name);
+
+                if name_cmp.is_eq() {
+                    left_properties.cmp(right_properties)
+                } else {
+                    name_cmp
+                }
+            },
+            (ValueNode::Struct {..}, _) => Ordering::Greater,
+            (
+                ValueNode::Enum {
+                    name: left_name, variant: left_variant, expression: left_expression
+                },
+                ValueNode::Enum {
+                    name: right_name, variant: right_variant, expression: right_expression
+                }
+            ) => {
+                let name_cmp = left_name.cmp(right_name);
+
+                if name_cmp.is_eq() {
+                    let variant_cmp = left_variant.cmp(right_variant);
+
+                    if variant_cmp.is_eq() {
+                        left_expression.cmp(right_expression)
+                    } else {
+                        variant_cmp
+                    }
+                } else {
+                    name_cmp
+                }
+            },
+            (ValueNode::Enum { .. }, _) => Ordering::Greater,
+            (ValueNode::Range(left), ValueNode::Range(right)) => left.clone().cmp(right.clone()),
+            (ValueNode::Range(_), _) => Ordering::Less,
+        }
+    }
+}
+
+impl PartialOrd for ValueNode {
+    fn partial_cmp(&self, other: &Self) -> Option<Ordering> {
+        Some(self.cmp(other))
+    }
+}

src/abstract_tree/while.rs

@@ -0,0 +1,64 @@
+use serde::{Deserialize, Serialize};
+
+use crate::{
+    error::{RuntimeError, SyntaxError, ValidationError},
+    AbstractTree, Block, Context, Expression, Format, SyntaxNode, Type, Value,
+};
+
+/// Abstract representation of a while loop.
+///
+/// While executes its block repeatedly until its expression evaluates to true.
+#[derive(Debug, Clone, Serialize, Deserialize, Eq, PartialEq, PartialOrd, Ord)]
+pub struct While {
+    expression: Expression,
+    block: Block,
+}
+
+impl AbstractTree for While {
+    fn from_syntax(node: SyntaxNode, source: &str, context: &Context) -> Result<Self, SyntaxError> {
+        SyntaxError::expect_syntax_node("while", node)?;
+
+        let expression_node = node.child(1).unwrap();
+        let expression = Expression::from_syntax(expression_node, source, context)?;
+
+        let block_node = node.child(2).unwrap();
+        let block = Block::from_syntax(block_node, source, context)?;
+
+        Ok(While { expression, block })
+    }
+
+    fn expected_type(&self, context: &Context) -> Result<Type, ValidationError> {
+        self.block.expected_type(context)
+    }
+
+    fn validate(&self, _source: &str, context: &Context) -> Result<(), ValidationError> {
+        log::info!("VALIDATE while loop");
+
+        self.expression.validate(_source, context)?;
+        self.block.validate(_source, context)
+    }
+
+    fn run(&self, source: &str, context: &Context) -> Result<Value, RuntimeError> {
+        log::info!("RUN while loop start");
+
+        while self.expression.run(source, context)?.as_boolean()? {
+            self.block.run(source, context)?;
+        }
+
+        log::info!("RUN while loop end");
+
+        Ok(Value::none())
+    }
+}
+
+impl Format for While {
+    fn format(&self, output: &mut String, indent_level: u8) {
+        output.push('\n');
+        While::indent(output, indent_level);
+        output.push_str("while ");
+        self.expression.format(output, indent_level);
+        output.push(' ');
+        self.block.format(output, indent_level);
+        output.push('\n');
+    }
+}

src/built_in_functions/fs.rs

@@ -0,0 +1,55 @@
+use std::fs::read_to_string;
+
+use enum_iterator::{all, Sequence};
+use serde::{Deserialize, Serialize};
+
+use crate::{error::RuntimeError, Context, Type, Value};
+
+use super::Callable;
+
+pub fn fs_functions() -> impl Iterator<Item = Fs> {
+    all()
+}
+
+#[derive(Sequence, Debug, Copy, Clone, Serialize, Deserialize, PartialEq, Eq, PartialOrd, Ord)]
+pub enum Fs {
+    ReadFile,
+}
+
+impl Callable for Fs {
+    fn name(&self) -> &'static str {
+        match self {
+            Fs::ReadFile => "read_file",
+        }
+    }
+
+    fn description(&self) -> &'static str {
+        match self {
+            Fs::ReadFile => "Read the contents of a file to a string.",
+        }
+    }
+
+    fn r#type(&self) -> Type {
+        match self {
+            Fs::ReadFile => Type::function(vec![Type::String], Type::String),
+        }
+    }
+
+    fn call(
+        &self,
+        arguments: &[Value],
+        _source: &str,
+        _outer_context: &Context,
+    ) -> Result<Value, RuntimeError> {
+        match self {
+            Fs::ReadFile => {
+                RuntimeError::expect_argument_amount(self.name(), 1, arguments.len())?;
+
+                let path = arguments.first().unwrap().as_string()?;
+                let file_content = read_to_string(path.as_str())?;
+
+                Ok(Value::string(file_content))
+            }
+        }
+    }
+}

src/built_in_functions/json.rs

@@ -0,0 +1,77 @@
+use enum_iterator::Sequence;
+use serde::{Deserialize, Serialize};
+
+use crate::{error::RuntimeError, Context, Type, Value};
+
+use super::Callable;
+
+pub fn json_functions() -> impl Iterator<Item = Json> {
+    enum_iterator::all()
+}
+
+#[derive(Sequence, Debug, Copy, Clone, Serialize, Deserialize, PartialEq, Eq, PartialOrd, Ord)]
+pub enum Json {
+    Create,
+    CreatePretty,
+    Parse,
+}
+
+impl Callable for Json {
+    fn name(&self) -> &'static str {
+        match self {
+            Json::Create => "create",
+            Json::CreatePretty => "create_pretty",
+            Json::Parse => "parse",
+        }
+    }
+
+    fn description(&self) -> &'static str {
+        match self {
+            Json::Create => "Convert a value to a JSON string.",
+            Json::CreatePretty => "Convert a value to a formatted JSON string.",
+            Json::Parse => "Convert JSON to a value",
+        }
+    }
+
+    fn r#type(&self) -> Type {
+        match self {
+            Json::Create => Type::function(vec![Type::Any], Type::String),
+            Json::CreatePretty => Type::function(vec![Type::Any], Type::String),
+            Json::Parse => Type::function(vec![Type::String], Type::Any),
+        }
+    }
+
+    fn call(
+        &self,
+        arguments: &[Value],
+        _source: &str,
+        _outer_context: &Context,
+    ) -> Result<Value, RuntimeError> {
+        match self {
+            Json::Create => {
+                RuntimeError::expect_argument_amount(self.name(), 1, arguments.len())?;
+
+                let value = arguments.first().unwrap();
+                let json_string = serde_json::to_string(value)?;
+
+                Ok(Value::String(json_string))
+            }
+            Json::CreatePretty => {
+                RuntimeError::expect_argument_amount(self.name(), 1, arguments.len())?;
+
+                let value = arguments.first().unwrap();
+                let json_string = serde_json::to_string_pretty(value)?;
+
+                Ok(Value::String(json_string))
+            }
+            Json::Parse => {
+                RuntimeError::expect_argument_amount(self.name(), 1, arguments.len())?;
+
+                let json_string = arguments.first().unwrap().as_string()?;
+                let value = serde_json::from_str(json_string)?;
+
+                Ok(value)
+            }
+        }
+    }
+}

src/built_in_functions/mod.rs

@@ -0,0 +1,198 @@
+pub mod fs;
+pub mod json;
+pub mod str;
+
+use std::fmt::{self, Display, Formatter};
+
+use rand::{random, thread_rng, Rng};
+use serde::{Deserialize, Serialize};
+
+use crate::{
+    error::{RuntimeError, ValidationError},
+    Context, EnumInstance, Format, Identifier, Type, Value,
+};
+
+use self::{fs::Fs, json::Json, str::StrFunction};
+
+pub trait Callable {
+    fn name(&self) -> &'static str;
+    fn description(&self) -> &'static str;
+    fn r#type(&self) -> Type;
+    fn call(
+        &self,
+        arguments: &[Value],
+        source: &str,
+        context: &Context,
+    ) -> Result<Value, RuntimeError>;
+}
+
+#[derive(Debug, Copy, Clone, Serialize, Deserialize, PartialEq, Eq, PartialOrd, Ord)]
+pub enum BuiltInFunction {
+    AssertEqual,
+    Fs(Fs),
+    Json(Json),
+    Length,
+    Output,
+    RandomBoolean,
+    RandomFloat,
+    RandomFrom,
+    RandomInteger,
+    String(StrFunction),
+}
+
+impl Callable for BuiltInFunction {
+    fn name(&self) -> &'static str {
+        match self {
+            BuiltInFunction::AssertEqual => "assert_equal",
+            BuiltInFunction::Fs(fs_function) => fs_function.name(),
+            BuiltInFunction::Json(json_function) => json_function.name(),
+            BuiltInFunction::Length => "length",
+            BuiltInFunction::Output => "output",
+            BuiltInFunction::RandomBoolean => "boolean",
+            BuiltInFunction::RandomFloat => "float",
+            BuiltInFunction::RandomFrom => "from",
+            BuiltInFunction::RandomInteger => "integer",
+            BuiltInFunction::String(string_function) => string_function.name(),
+        }
+    }
+
+    fn description(&self) -> &'static str {
+        match self {
+            BuiltInFunction::AssertEqual => "assert_equal",
+            BuiltInFunction::Fs(fs_function) => fs_function.description(),
+            BuiltInFunction::Json(json_function) => json_function.description(),
+            BuiltInFunction::Length => "length",
+            BuiltInFunction::Output => "output",
+            BuiltInFunction::RandomBoolean => "boolean",
+            BuiltInFunction::RandomFloat => "float",
+            BuiltInFunction::RandomFrom => "from",
+            BuiltInFunction::RandomInteger => "integer",
+            BuiltInFunction::String(string_function) => string_function.description(),
+        }
+    }
+
+    fn r#type(&self) -> Type {
+        match self {
+            BuiltInFunction::AssertEqual => Type::function(vec![Type::Any, Type::Any], Type::None),
+            BuiltInFunction::Fs(fs_function) => fs_function.r#type(),
+            BuiltInFunction::Json(json_function) => json_function.r#type(),
+            BuiltInFunction::Length => Type::function(vec![Type::Collection], Type::Integer),
+            BuiltInFunction::Output => Type::function(vec![Type::Any], Type::None),
+            BuiltInFunction::RandomBoolean => Type::function(vec![], Type::Boolean),
+            BuiltInFunction::RandomFloat => Type::function(vec![], Type::Float),
+            BuiltInFunction::RandomFrom => Type::function(vec![Type::Collection], Type::Any),
+            BuiltInFunction::RandomInteger => Type::function(vec![], Type::Integer),
+            BuiltInFunction::String(string_function) => string_function.r#type(),
+        }
+    }
+
+    fn call(
+        &self,
+        arguments: &[Value],
+        _source: &str,
+        context: &Context,
+    ) -> Result<Value, RuntimeError> {
+        match self {
+            BuiltInFunction::AssertEqual => {
+                RuntimeError::expect_argument_amount(self.name(), 2, arguments.len())?;
+
+                let left = arguments.get(0).unwrap();
+                let right = arguments.get(1).unwrap();
+
+                if left == right {
+                    Ok(Value::Enum(EnumInstance::new(
+                        Identifier::new("Result"),
+                        Identifier::new("Ok"),
+                        Some(Value::none()),
+                    )))
+                } else {
+                    Err(RuntimeError::AssertEqualFailed {
+                        left: left.clone(),
+                        right: right.clone(),
+                    })
+                }
+            }
+            BuiltInFunction::Fs(fs_function) => fs_function.call(arguments, _source, context),
+            BuiltInFunction::Json(json_function) => json_function.call(arguments, _source, context),
+            BuiltInFunction::Length => {
+                RuntimeError::expect_argument_amount(self.name(), 1, arguments.len())?;
+
+                let value = arguments.first().unwrap();
+                let length = if let Ok(list) = value.as_list() {
+                    list.items()?.len()
+                } else if let Ok(map) = value.as_map() {
+                    map.inner().len()
+                } else if let Ok(str) = value.as_string() {
+                    str.chars().count()
+                } else {
+                    return Err(RuntimeError::ValidationFailure(
+                        ValidationError::ExpectedCollection {
+                            actual: value.clone(),
+                        },
+                    ));
+                };
+
+                Ok(Value::Integer(length as i64))
+            }
+            BuiltInFunction::Output => {
+                RuntimeError::expect_argument_amount(self.name(), 1, arguments.len())?;
+
+                let value = arguments.first().unwrap();
+
+                println!("{value}");
+
+                Ok(Value::none())
+            }
+            BuiltInFunction::RandomBoolean => {
+                RuntimeError::expect_argument_amount(self.name(), 0, arguments.len())?;
+
+                Ok(Value::Boolean(random()))
+            }
+            BuiltInFunction::RandomFloat => {
+                RuntimeError::expect_argument_amount(self.name(), 0, arguments.len())?;
+
+                Ok(Value::Float(random()))
+            }
+            BuiltInFunction::RandomFrom => {
+                RuntimeError::expect_argument_amount(self.name(), 1, arguments.len())?;
+
+                let value = arguments.first().unwrap();
+
+                if let Ok(list) = value.as_list() {
+                    let items = list.items()?;
+
+                    if items.len() == 0 {
+                        Ok(Value::none())
+                    } else {
+                        let random_index = thread_rng().gen_range(0..items.len());
+                        let random_value = items.get(random_index).cloned().unwrap_or_default();
+
+                        Ok(random_value)
+                    }
+                } else {
+                    todo!()
+                }
+            }
+            BuiltInFunction::RandomInteger => {
+                RuntimeError::expect_argument_amount(self.name(), 0, arguments.len())?;
+
+                Ok(Value::Integer(random()))
+            }
+            BuiltInFunction::String(string_function) => {
+                string_function.call(arguments, _source, context)
+            }
+        }
+    }
+}
+
+impl Format for BuiltInFunction {
+    fn format(&self, output: &mut String, _indent_level: u8) {
+        output.push_str(self.name());
+    }
+}
+
+impl Display for BuiltInFunction {
+    fn fmt(&self, f: &mut Formatter) -> fmt::Result {
+        write!(f, "{}", self.name())
+    }
+}

src/built_in_functions/str.rs

@@ -0,0 +1,591 @@
+use enum_iterator::Sequence;
+use serde::{Deserialize, Serialize};
+
+use crate::{error::RuntimeError, Context, EnumInstance, Identifier, List, Type, Value};
+
+use super::Callable;
+
+pub fn string_functions() -> impl Iterator<Item = StrFunction> {
+    enum_iterator::all()
+}
+
+#[derive(Sequence, Debug, Copy, Clone, Serialize, Deserialize, PartialEq, Eq, PartialOrd, Ord)]
+pub enum StrFunction {
+    AsBytes,
+    EndsWith,
+    Find,
+    Insert,
+    IsAscii,
+    IsEmpty,
+    Lines,
+    Matches,
+    Parse,
+    Remove,
+    ReplaceRange,
+    Retain,
+    Split,
+    SplitAt,
+    SplitInclusive,
+    SplitN,
+    SplitOnce,
+    SplitTerminator,
+    SplitWhitespace,
+    StartsWith,
+    StripPrefix,
+    ToLowercase,
+    ToUppercase,
+    Trim,
+    TrimEnd,
+    TrimEndMatches,
+    TrimMatches,
+    TrimStart,
+    TrimStartMatches,
+    Truncate,
+}
+
+impl Callable for StrFunction {
+    fn name(&self) -> &'static str {
+        match self {
+            StrFunction::AsBytes => "as_bytes",
+            StrFunction::EndsWith => "ends_with",
+            StrFunction::Find => "find",
+            StrFunction::Insert => "insert",
+            StrFunction::IsAscii => "is_ascii",
+            StrFunction::IsEmpty => "is_empty",
+            StrFunction::Lines => "lines",
+            StrFunction::Matches => "matches",
+            StrFunction::Parse => "parse",
+            StrFunction::Remove => "remove",
+            StrFunction::ReplaceRange => "replace_range",
+            StrFunction::Retain => "retain",
+            StrFunction::Split => "split",
+            StrFunction::SplitAt => "split_at",
+            StrFunction::SplitInclusive => "split_inclusive",
+            StrFunction::SplitN => "split_n",
+            StrFunction::SplitOnce => "split_once",
+            StrFunction::SplitTerminator => "split_terminator",
+            StrFunction::SplitWhitespace => "split_whitespace",
+            StrFunction::StartsWith => "starts_with",
+            StrFunction::StripPrefix => "strip_prefix",
+            StrFunction::ToLowercase => "to_lowercase",
+            StrFunction::ToUppercase => "to_uppercase",
+            StrFunction::Trim => "trim",
+            StrFunction::TrimEnd => "trim_end",
+            StrFunction::TrimEndMatches => "trim_end_matches",
+            StrFunction::TrimMatches => "trim_matches",
+            StrFunction::TrimStart => "trim_start",
+            StrFunction::TrimStartMatches => "trim_start_matches",
+            StrFunction::Truncate => "truncate",
+        }
+    }
+
+    fn description(&self) -> &'static str {
+        match self {
+            StrFunction::AsBytes => "TODO",
+            StrFunction::EndsWith => "TODO",
+            StrFunction::Find => "TODO",
+            StrFunction::Insert => "TODO",
+            StrFunction::IsAscii => "TODO",
+            StrFunction::IsEmpty => "TODO",
+            StrFunction::Lines => "TODO",
+            StrFunction::Matches => "TODO",
+            StrFunction::Parse => "TODO",
+            StrFunction::Remove => "TODO",
+            StrFunction::ReplaceRange => "TODO",
+            StrFunction::Retain => "TODO",
+            StrFunction::Split => "TODO",
+            StrFunction::SplitAt => "TODO",
+            StrFunction::SplitInclusive => "TODO",
+            StrFunction::SplitN => "TODO",
+            StrFunction::SplitOnce => "TODO",
+            StrFunction::SplitTerminator => "TODO",
+            StrFunction::SplitWhitespace => "TODO",
+            StrFunction::StartsWith => "TODO",
+            StrFunction::StripPrefix => "TODO",
+            StrFunction::ToLowercase => "TODO",
+            StrFunction::ToUppercase => "TODO",
+            StrFunction::Trim => "TODO",
+            StrFunction::TrimEnd => "TODO",
+            StrFunction::TrimEndMatches => "TODO",
+            StrFunction::TrimMatches => "TODO",
+            StrFunction::TrimStart => "TODO",
+            StrFunction::TrimStartMatches => "TODO",
+            StrFunction::Truncate => "TODO",
+        }
+    }
+
+    fn r#type(&self) -> Type {
+        match self {
+            StrFunction::AsBytes => Type::function(vec![Type::String], Type::list(Type::Integer)),
+            StrFunction::EndsWith => {
+                Type::function(vec![Type::String, Type::String], Type::Boolean)
+            }
+            StrFunction::Find => Type::function(
+                vec![Type::String, Type::String],
+                Type::option(Some(Type::Integer)),
+            ),
+            StrFunction::Insert => Type::function(
+                vec![Type::String, Type::Integer, Type::String],
+                Type::String,
+            ),
+            StrFunction::IsAscii => Type::function(vec![Type::String], Type::Boolean),
+            StrFunction::IsEmpty => Type::function(vec![Type::String], Type::Boolean),
+            StrFunction::Lines => Type::function(vec![Type::String], Type::list(Type::String)),
+            StrFunction::Matches => {
+                Type::function(vec![Type::String, Type::String], Type::list(Type::String))
+            }
+            StrFunction::Parse => Type::function(vec![Type::String], Type::Any),
+            StrFunction::Remove => Type::function(
+                vec![Type::String, Type::Integer],
+                Type::option(Some(Type::String)),
+            ),
+            StrFunction::ReplaceRange => Type::function(
+                vec![Type::String, Type::list(Type::Integer), Type::String],
+                Type::String,
+            ),
+            StrFunction::Retain => Type::function(
+                vec![
+                    Type::String,
+                    Type::function(vec![Type::String], Type::Boolean),
+                ],
+                Type::String,
+            ),
+            StrFunction::Split => {
+                Type::function(vec![Type::String, Type::String], Type::list(Type::String))
+            }
+            StrFunction::SplitAt => {
+                Type::function(vec![Type::String, Type::Integer], Type::list(Type::String))
+            }
+            StrFunction::SplitInclusive => {
+                Type::function(vec![Type::String, Type::String], Type::list(Type::String))
+            }
+            StrFunction::SplitN => Type::function(
+                vec![Type::String, Type::Integer, Type::String],
+                Type::list(Type::String),
+            ),
+            StrFunction::SplitOnce => {
+                Type::function(vec![Type::String, Type::String], Type::list(Type::String))
+            }
+            StrFunction::SplitTerminator => {
+                Type::function(vec![Type::String, Type::String], Type::list(Type::String))
+            }
+            StrFunction::SplitWhitespace => {
+                Type::function(vec![Type::String], Type::list(Type::String))
+            }
+            StrFunction::StartsWith => {
+                Type::function(vec![Type::String, Type::String], Type::Boolean)
+            }
+            StrFunction::StripPrefix => Type::function(
+                vec![Type::String, Type::String],
+                Type::option(Some(Type::String)),
+            ),
+            StrFunction::ToLowercase => Type::function(vec![Type::String], Type::String),
+            StrFunction::ToUppercase => Type::function(vec![Type::String], Type::String),
+            StrFunction::Truncate => {
+                Type::function(vec![Type::String, Type::Integer], Type::String)
+            }
+            StrFunction::Trim => Type::function(vec![Type::String], Type::String),
+            StrFunction::TrimEnd => Type::function(vec![Type::String], Type::String),
+            StrFunction::TrimEndMatches => {
+                Type::function(vec![Type::String, Type::String], Type::String)
+            }
+            StrFunction::TrimMatches => {
+                Type::function(vec![Type::String, Type::String], Type::String)
+            }
+            StrFunction::TrimStart => Type::function(vec![Type::String], Type::String),
+            StrFunction::TrimStartMatches => {
+                Type::function(vec![Type::String, Type::String], Type::String)
+            }
+        }
+    }
+
+    fn call(
+        &self,
+        arguments: &[Value],
+        _source: &str,
+        _context: &Context,
+    ) -> Result<Value, RuntimeError> {
+        let value = match self {
+            StrFunction::AsBytes => {
+                RuntimeError::expect_argument_amount(self.name(), 1, arguments.len())?;
+
+                let string = arguments.first().unwrap().as_string()?;
+                let bytes = string
+                    .bytes()
+                    .map(|byte| Value::Integer(byte as i64))
+                    .collect();
+
+                Value::List(List::with_items(bytes))
+            }
+            StrFunction::EndsWith => {
+                RuntimeError::expect_argument_amount(self.name(), 2, arguments.len())?;
+
+                let string = arguments.first().unwrap().as_string()?;
+                let pattern_string = arguments.get(1).unwrap().as_string()?;
+                let pattern = pattern_string.as_str();
+
+                Value::Boolean(string.ends_with(pattern))
+            }
+            StrFunction::Find => {
+                RuntimeError::expect_argument_amount(self.name(), 2, arguments.len())?;
+
+                let string = arguments.first().unwrap().as_string()?;
+                let pattern_string = arguments.get(1).unwrap().as_string()?;
+                let pattern = pattern_string.as_str();
+                let find = string
+                    .find(pattern)
+                    .map(|index| Value::Integer(index as i64));
+
+                if let Some(index) = find {
+                    Value::Enum(EnumInstance::new(
+                        Identifier::new("Option"),
+                        Identifier::new("Some"),
+                        Some(index),
+                    ))
+                } else {
+                    Value::Enum(EnumInstance::new(
+                        Identifier::new("Option"),
+                        Identifier::new("None"),
+                        Some(Value::none()),
+                    ))
+                }
+            }
+            StrFunction::IsAscii => {
+                RuntimeError::expect_argument_amount(self.name(), 1, arguments.len())?;
+
+                let string = arguments.first().unwrap().as_string()?;
+
+                Value::Boolean(string.is_ascii())
+            }
+            StrFunction::IsEmpty => {
+                RuntimeError::expect_argument_amount(self.name(), 1, arguments.len())?;
+
+                let string = arguments.first().unwrap().as_string()?;
+
+                Value::Boolean(string.is_empty())
+            }
+            StrFunction::Insert => {
+                RuntimeError::expect_argument_amount(self.name(), 3, arguments.len())?;
+
+                let mut string = arguments.first().unwrap().as_string()?.clone();
+                let index = arguments.get(1).unwrap().as_integer()? as usize;
+                let insertion = arguments.get(2).unwrap().as_string()?;
+
+                string.insert_str(index, insertion);
+
+                Value::String(string)
+            }
+            StrFunction::Lines => {
+                RuntimeError::expect_argument_amount(self.name(), 1, arguments.len())?;
+
+                let string = arguments.first().unwrap().as_string()?;
+                let lines = string
+                    .lines()
+                    .map(|line| Value::string(line.to_string()))
+                    .collect();
+
+                Value::List(List::with_items(lines))
+            }
+            StrFunction::Matches => {
+                RuntimeError::expect_argument_amount(self.name(), 2, arguments.len())?;
+
+                let string = arguments.first().unwrap().as_string()?;
+                let pattern_string = arguments.get(1).unwrap().as_string()?;
+                let pattern = pattern_string.as_str();
+                let matches = string
+                    .matches(pattern)
+                    .map(|pattern| Value::string(pattern.to_string()))
+                    .collect();
+
+                Value::List(List::with_items(matches))
+            }
+            StrFunction::Parse => {
+                RuntimeError::expect_argument_amount(self.name(), 1, arguments.len())?;
+
+                let string = arguments.first().unwrap().as_string()?;
+
+                if let Ok(integer) = string.parse::<i64>() {
+                    Value::Integer(integer)
+                } else if let Ok(float) = string.parse::<f64>() {
+                    Value::Float(float)
+                } else {
+                    Value::none()
+                }
+            }
+            StrFunction::Remove => {
+                RuntimeError::expect_argument_amount(self.name(), 2, arguments.len())?;
+
+                let string = arguments.first().unwrap().as_string()?;
+                let index = arguments.get(1).unwrap().as_integer()? as usize;
+                let chars = string.chars().collect::<Vec<char>>();
+
+                if index < chars.len() {
+                    let new_string = chars
+                        .iter()
+                        .map(|char| char.to_string())
+                        .collect::<String>();
+
+                    Value::some(Value::string(new_string))
+                } else {
+                    Value::none()
+                }
+            }
+            StrFunction::ReplaceRange => {
+                RuntimeError::expect_argument_amount(self.name(), 3, arguments.len())?;
+
+                let mut string = arguments.first().unwrap().as_string()?.clone();
+                let range = arguments.get(1).unwrap().as_list()?.items()?;
+                let start = range[0].as_integer()? as usize;
+                let end = range[1].as_integer()? as usize;
+                let pattern = arguments.get(2).unwrap().as_string()?;
+
+                string.replace_range(start..end, pattern);
+
+                Value::String(string)
+            }
+            StrFunction::Retain => {
+                RuntimeError::expect_argument_amount(self.name(), 2, arguments.len())?;
+
+                todo!();
+
+                // let mut string = arguments.first().unwrap().as_string()?.clone();
+                // let predicate = arguments.get(1).unwrap().as_function()?;
+
+                // string.retain(|char| {
+                //     predicate
+                //         .call(&[Value::string(char)], _source, _outer_context)
+                //         .unwrap()
+                //         .as_boolean()
+                //         .unwrap()
+                // });
+
+                // Value::String(string)
+            }
+            StrFunction::Split => {
+                RuntimeError::expect_argument_amount(self.name(), 2, arguments.len())?;
+
+                let string = arguments.first().unwrap().as_string()?;
+                let pattern_string = arguments.get(1).unwrap().as_string()?;
+                let pattern = pattern_string.as_str();
+                let sections = string
+                    .split(pattern)
+                    .map(|section| Value::string(section.to_string()))
+                    .collect();
+
+                Value::List(List::with_items(sections))
+            }
+            StrFunction::SplitAt => {
+                RuntimeError::expect_argument_amount(self.name(), 2, arguments.len())?;
+
+                let string = arguments.first().unwrap().as_string()?;
+                let index = arguments.get(1).unwrap().as_integer()?;
+                let (left, right) = string.split_at(index as usize);
+
+                Value::List(List::with_items(vec![
+                    Value::string(left.to_string()),
+                    Value::string(right.to_string()),
+                ]))
+            }
+            StrFunction::SplitInclusive => {
+                RuntimeError::expect_argument_amount(self.name(), 2, arguments.len())?;
+
+                let string = arguments.first().unwrap().as_string()?;
+                let pattern_string = arguments.get(1).unwrap().as_string()?;
+                let pattern = pattern_string.as_str();
+                let sections = string
+                    .split(pattern)
+                    .map(|pattern| Value::string(pattern.to_string()))
+                    .collect();
+
+                Value::List(List::with_items(sections))
+            }
+            StrFunction::SplitN => {
+                RuntimeError::expect_argument_amount(self.name(), 3, arguments.len())?;
+
+                let string = arguments.first().unwrap().as_string()?;
+                let count = arguments.get(1).unwrap().as_integer()?;
+                let pattern_string = arguments.get(2).unwrap().as_string()?;
+                let pattern = pattern_string.as_str();
+                let sections = string
+                    .splitn(count as usize, pattern)
+                    .map(|pattern| Value::string(pattern.to_string()))
+                    .collect();
+
+                Value::List(List::with_items(sections))
+            }
+            StrFunction::SplitOnce => {
+                RuntimeError::expect_argument_amount(self.name(), 2, arguments.len())?;
+
+                let string = arguments.first().unwrap().as_string()?;
+                let pattern_string = arguments.get(1).unwrap().as_string()?;
+                let pattern = pattern_string.as_str();
+                let sections = string.split_once(pattern).map(|(left, right)| {
+                    Value::List(List::with_items(vec![
+                        Value::string(left.to_string()),
+                        Value::string(right.to_string()),
+                    ]))
+                });
+
+                if let Some(sections) = sections {
+                    Value::some(sections)
+                } else {
+                    Value::none()
+                }
+            }
+            StrFunction::SplitTerminator => {
+                RuntimeError::expect_argument_amount(self.name(), 2, arguments.len())?;
+
+                let string = arguments.first().unwrap().as_string()?;
+                let pattern_string = arguments.get(1).unwrap().as_string()?;
+                let pattern = pattern_string.as_str();
+                let sections = string
+                    .split_terminator(pattern)
+                    .map(|section| Value::string(section.to_string()))
+                    .collect();
+
+                Value::List(List::with_items(sections))
+            }
+            StrFunction::SplitWhitespace => {
+                RuntimeError::expect_argument_amount(self.name(), 1, arguments.len())?;
+
+                let string = arguments.first().unwrap().as_string()?;
+                let sections = string
+                    .split_whitespace()
+                    .map(|section| Value::string(section.to_string()))
+                    .collect();
+
+                Value::List(List::with_items(sections))
+            }
+            StrFunction::StartsWith => {
+                RuntimeError::expect_argument_amount(self.name(), 2, arguments.len())?;
+
+                let string = arguments.first().unwrap().as_string()?;
+                let pattern_string = arguments.get(1).unwrap().as_string()?;
+                let pattern = pattern_string.as_str();
+
+                Value::Boolean(string.starts_with(pattern))
+            }
+            StrFunction::StripPrefix => {
+                RuntimeError::expect_argument_amount(self.name(), 2, arguments.len())?;
+
+                let string = arguments.first().unwrap().as_string()?;
+                let prefix_string = arguments.get(1).unwrap().as_string()?;
+                let prefix = prefix_string.as_str();
+                let stripped = string
+                    .strip_prefix(prefix)
+                    .map(|remainder| Value::string(remainder.to_string()));
+
+                if let Some(value) = stripped {
+                    Value::Enum(EnumInstance::new(
+                        Identifier::new("Option"),
+                        Identifier::new("Some"),
+                        Some(value),
+                    ))
+                } else {
+                    Value::none()
+                }
+            }
+            StrFunction::ToLowercase => {
+                RuntimeError::expect_argument_amount(self.name(), 1, arguments.len())?;
+
+                let string = arguments.first().unwrap().as_string()?;
+                let lowercase = string.to_lowercase();
+
+                Value::string(lowercase)
+            }
+            StrFunction::ToUppercase => {
+                RuntimeError::expect_argument_amount(self.name(), 1, arguments.len())?;
+
+                let string = arguments.first().unwrap().as_string()?;
+                let uppercase = string.to_uppercase();
+
+                Value::string(uppercase)
+            }
+            StrFunction::Trim => {
+                RuntimeError::expect_argument_amount(self.name(), 1, arguments.len())?;
+
+                let trimmed = arguments.first().unwrap().as_string()?.trim().to_string();
+
+                Value::string(trimmed)
+            }
+            StrFunction::TrimEnd => {
+                RuntimeError::expect_argument_amount(self.name(), 1, arguments.len())?;
+
+                let trimmed = arguments
+                    .first()
+                    .unwrap()
+                    .as_string()?
+                    .trim_end()
+                    .to_string();
+
+                Value::string(trimmed)
+            }
+            StrFunction::TrimEndMatches => {
+                RuntimeError::expect_argument_amount(self.name(), 2, arguments.len())?;
+
+                let string = arguments.first().unwrap().as_string()?;
+                let pattern_string = arguments.get(1).unwrap().as_string()?;
+                let pattern = pattern_string.as_str();
+                let trimmed = string.trim_end_matches(pattern).to_string();
+
+                Value::string(trimmed)
+            }
+            StrFunction::TrimMatches => {
+                RuntimeError::expect_argument_amount(self.name(), 2, arguments.len())?;
+
+                let string = arguments.first().unwrap().as_string()?;
+                let pattern = arguments
+                    .get(1)
+                    .unwrap()
+                    .as_string()?
+                    .chars()
+                    .collect::<Vec<char>>();
+                let trimmed = string.trim_matches(pattern.as_slice()).to_string();
+
+                Value::string(trimmed)
+            }
+            StrFunction::TrimStart => {
+                RuntimeError::expect_argument_amount(self.name(), 1, arguments.len())?;
+
+                let trimmed = arguments
+                    .first()
+                    .unwrap()
+                    .as_string()?
+                    .trim_start()
+                    .to_string();
+
+                Value::string(trimmed)
+            }
+            StrFunction::TrimStartMatches => {
+                RuntimeError::expect_argument_amount(self.name(), 2, arguments.len())?;
+
+                let string = arguments.first().unwrap().as_string()?;
+                let pattern = arguments
+                    .get(1)
+                    .unwrap()
+                    .as_string()?
+                    .chars()
+                    .collect::<Vec<char>>();
+                let trimmed = string.trim_start_matches(pattern.as_slice()).to_string();
+
+                Value::string(trimmed)
+            }
+            StrFunction::Truncate => {
+                RuntimeError::expect_argument_amount(self.name(), 2, arguments.len())?;
+
+                let input_string = arguments.first().unwrap().as_string()?;
+                let new_length = arguments.get(1).unwrap().as_integer()? as usize;
+
+                let new_string = input_string
+                    .chars()
+                    .take(new_length)
+                    .map(|char| char.to_string())
+                    .collect();
+
+                Value::String(new_string)
+            }
+        };
+
+        Ok(value)
+    }
+}

src/built_in_identifiers.rs

@@ -0,0 +1,51 @@
+use std::sync::{Arc, OnceLock};
+
+use enum_iterator::{all, Sequence};
+
+use crate::Identifier;
+
+pub fn all_built_in_identifiers() -> impl Iterator<Item = BuiltInIdentifier> {
+    all()
+}
+
+static OPTION: OnceLock<Identifier> = OnceLock::new();
+static NONE: OnceLock<Identifier> = OnceLock::new();
+static SOME: OnceLock<Identifier> = OnceLock::new();
+static RESULT: OnceLock<Identifier> = OnceLock::new();
+static OK: OnceLock<Identifier> = OnceLock::new();
+static ERROR: OnceLock<Identifier> = OnceLock::new();
+
+#[derive(Sequence, Debug)]
+pub enum BuiltInIdentifier {
+    Option,
+    None,
+    Some,
+    Result,
+    Ok,
+    Error,
+}
+
+impl BuiltInIdentifier {
+    pub fn get(&self) -> &Identifier {
+        match self {
+            BuiltInIdentifier::Option => {
+                OPTION.get_or_init(|| Identifier::from_raw_parts(Arc::new("Option".to_string())))
+            }
+            BuiltInIdentifier::None => {
+                NONE.get_or_init(|| Identifier::from_raw_parts(Arc::new("None".to_string())))
+            }
+            BuiltInIdentifier::Some => {
+                SOME.get_or_init(|| Identifier::from_raw_parts(Arc::new("Some".to_string())))
+            }
+            BuiltInIdentifier::Result => {
+                RESULT.get_or_init(|| Identifier::from_raw_parts(Arc::new("Result".to_string())))
+            }
+            BuiltInIdentifier::Ok => {
+                OK.get_or_init(|| Identifier::from_raw_parts(Arc::new("Ok".to_string())))
+            }
+            BuiltInIdentifier::Error => {
+                ERROR.get_or_init(|| Identifier::from_raw_parts(Arc::new("Error".to_string())))
+            }
+        }
+    }
+}