Write docs; Update logging and error messages

README.md

@@ -1,6 +1,6 @@
 # Dust
 
-High-level programming language with effortless concurrency, automatic memory management and first class functions.
+High-level programming language with effortless concurrency, automatic memory management, type safety and strict error handling.
 
 ![Dust version of an example from The Rust Programming Language.](https://git.jeffa.io/jeff/dust/docs/assets/example_0.png)
 
@@ -8,6 +8,7 @@ High-level programming language with effortless concurrency, automatic memory ma
 - [Dust](#dust)
   - [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)
@@ -15,10 +16,44 @@ High-level programming language with effortless concurrency, automatic memory ma
 
 ## Easy to Read and Write
 
+Dust has simple, easy-to-learn syntax.
+
+```js
+output('Hello world!')
+```
+
 ## Effortless Concurrency
 
+Write multi-threaded code as easily as you would write code for a single thread.
+
+```js
+async {
+    output('Will this one print first?')
+    output('Or will this one?')
+    output('Who knows! Each "output" will run in its own thread!')
+}
+```
+
+## Helpful Errors
+
+Dust shows you exactly where your code went wrong and suggests changes.
+
+![Example of syntax error output.](https://git.jeffa.io/jeff/dust/docs/assets/syntax_error.png)
+
+## Static analysis
+
+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
+
+![Example of type error output.](https://git.jeffa.io/jeff/dust/docs/assets/type_error.png)
+
 ## Debugging
 
+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

src/abstract_tree/assignment.rs

@@ -60,6 +60,8 @@ impl AbstractTree for Assignment {
                 self.statement.expected_type(context)?
             };
 
+            log::info!("Setting type: {} <{}>", self.identifier, r#type);
+
             context.set_type(self.identifier.clone(), r#type)?;
         }
 
@@ -155,6 +157,8 @@ impl AbstractTree for Assignment {
                 .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())

src/abstract_tree/logic.rs

@@ -45,6 +45,8 @@ impl AbstractTree for Logic {
     }
 
     fn validate(&self, _source: &str, _context: &Context) -> Result<(), ValidationError> {
+        log::info!("VALIDATE logic expression");
+
         self.left.validate(_source, _context)?;
         self.right.validate(_source, _context)
     }
@@ -52,6 +54,9 @@ impl AbstractTree for Logic {
     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()) {

src/abstract_tree/logic_operator.rs

@@ -1,3 +1,5 @@
+use std::fmt::{self, Display, Formatter};
+
 use serde::{Deserialize, Serialize};
 
 use crate::{
@@ -74,3 +76,18 @@ impl Format for LogicOperator {
         }
     }
 }
+
+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/math_operator.rs

@@ -20,6 +20,8 @@ impl AbstractTree for MathOperator {
         _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,

src/abstract_tree/value_node.rs

@@ -179,7 +179,7 @@ impl AbstractTree for ValueNode {
                 }
             }
             ValueNode::Map(map_node) => map_node.validate(_source, context)?,
-            ValueNode::Enum { name, variant, expression } => {
+            ValueNode::Enum { name, expression, .. } => {
                 name.validate(_source, context)?;
 
                 if let Some(expression) = expression {

src/abstract_tree/while.rs

@@ -32,15 +32,21 @@ impl AbstractTree for While {
     }
 
     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())
     }
 }

src/context/mod.rs

@@ -264,8 +264,6 @@ impl Context {
 
     /// Set a value to a key.
     pub fn set_value(&self, key: Identifier, value: Value) -> Result<(), RwLockError> {
-        log::info!("Setting value: {key} = {value}");
-
         let mut map = self.inner.write()?;
         let old_data = map.remove(&key);
 
@@ -283,8 +281,6 @@ impl Context {
     /// This allows the interpreter to check a value's type before the value
     /// actually exists by predicting what the abstract tree will produce.
     pub fn set_type(&self, key: Identifier, r#type: Type) -> Result<(), RwLockError> {
-        log::info!("Setting type: {key} <{}>", r#type);
-
         self.inner
             .write()?
             .insert(key, (ValueData::TypeHint(r#type), UsageCounter::new()));

src/error/syntax_error.rs

@@ -1,5 +1,6 @@
 use std::fmt::{self, Display, Formatter};
 
+use colored::Colorize;
 use lyneate::Report;
 use serde::{Deserialize, Serialize};
 use tree_sitter::Node as SyntaxNode;
@@ -12,6 +13,8 @@ use super::rw_lock_error::RwLockError;
 pub enum SyntaxError {
     /// Invalid user input.
     InvalidSource {
+        expected: String,
+        actual: String,
         position: SourcePosition,
     },
 
@@ -27,25 +30,25 @@ pub enum SyntaxError {
 impl SyntaxError {
     pub fn create_report(&self, source: &str) -> String {
         let messages = match self {
-            SyntaxError::InvalidSource { position } => {
+            SyntaxError::InvalidSource { position, .. } => self
+                .to_string()
+                .split_inclusive(".")
+                .map(|message_part| {
+                    (
+                        position.start_byte..position.end_byte,
+                        message_part.to_string(),
+                        (255, 200, 100),
+                    )
+                })
+                .collect(),
+            SyntaxError::RwLock(_) => todo!(),
+            SyntaxError::UnexpectedSyntaxNode { position, .. } => {
                 vec![(
                     position.start_byte..position.end_byte,
-                    format!(
-                        "Invalid syntax from ({}, {}) to ({}, {}).",
-                        position.start_row,
-                        position.start_column,
-                        position.end_row,
-                        position.end_column,
-                    ),
+                    self.to_string(),
                     (255, 200, 100),
                 )]
             }
-            SyntaxError::RwLock(_) => todo!(),
-            SyntaxError::UnexpectedSyntaxNode {
-                expected: _,
-                actual: _,
-                position: _,
-            } => todo!(),
         };
 
         Report::new_byte_spanned(source, messages).display_str()
@@ -58,6 +61,8 @@ impl SyntaxError {
             Ok(())
         } else if actual.is_error() {
             Err(SyntaxError::InvalidSource {
+                expected: expected.to_owned(),
+                actual: actual.kind().to_string(),
                 position: SourcePosition::from(actual.range()),
             })
         } else {
@@ -79,16 +84,43 @@ impl From<RwLockError> for SyntaxError {
 impl Display for SyntaxError {
     fn fmt(&self, f: &mut Formatter<'_>) -> fmt::Result {
         match self {
-            SyntaxError::InvalidSource { position } => write!(f, "Invalid syntax at {position:?}."),
+            SyntaxError::InvalidSource {
+                expected,
+                actual,
+                position,
+            } => {
+                let actual = if actual == "ERROR" {
+                    "unrecognized characters"
+                } else {
+                    actual
+                };
+
+                write!(
+                    f,
+                    "Invalid syntax from ({}, {}) to ({}, {}). Exected {} but found {}.",
+                    position.start_row,
+                    position.start_column,
+                    position.end_row,
+                    position.end_column,
+                    expected.bold().green(),
+                    actual.bold().red(),
+                )
+            }
             SyntaxError::RwLock(_) => todo!(),
             SyntaxError::UnexpectedSyntaxNode {
                 expected,
                 actual,
                 position,
-            } => write!(
+            } => {
+                write!(
                         f,
-                "Unexpected syntax node. Expected {expected} but got {actual} at {position:?}."
-            ),
+                        "Interpreter Error. Tried to parse {actual} as {expected} from ({}, {}) to ({}, {}).",
+                        position.start_row,
+                        position.start_column,
+                        position.end_row,
+                        position.end_column,
+                    )
+            }
         }
     }
 }

src/error/validation_error.rs

@@ -1,5 +1,6 @@
 use std::fmt::{self, Display, Formatter};
 
+use colored::Colorize;
 use lyneate::Report;
 use serde::{Deserialize, Serialize};
 
@@ -223,10 +224,17 @@ impl ValidationError {
                 position,
             } => vec![(
                 position.start_byte..position.end_byte,
-                format!("Type {actual} is incompatible with {expected}."),
+                format!(
+                    "Type {} is incompatible with {}.",
+                    actual.to_string().bold().red(),
+                    expected.to_string().bold().green()
+                ),
                 (200, 200, 200),
             )],
-            ValidationError::TypeCheckExpectedFunction { actual: _, position: _ } => todo!(),
+            ValidationError::TypeCheckExpectedFunction {
+                actual: _,
+                position: _,
+            } => todo!(),
             ValidationError::VariableIdentifierNotFound(_) => todo!(),
             ValidationError::TypeDefinitionNotFound(_) => todo!(),
             ValidationError::ExpectedEnumDefintion { actual: _ } => todo!(),