Add enum type validation

dust-lang/src/abstract_tree/if_else.rs

@@ -73,6 +73,7 @@ impl AbstractNode for IfElse {
                             .map_err(|conflict| ValidationError::TypeCheck {
                                 conflict,
                                 actual_position: self.if_block.node.last_statement().position(),
+
                                 expected_position: Some(self.if_expression.position()),
                             })?;
                     }

dust-lang/src/abstract_tree/value_node.rs

@@ -111,25 +111,41 @@ impl AbstractNode for ValueNode {
                 expression.define_and_validate(context, _manage_memory, scope)?;
             }
 
-            if let Some(Type::Enum { name, variants, .. }) = context.get_type(&type_name.node)? {
+            if let Some(Type::Enum {
+                variants,
+                type_parameters,
+                ..
+            }) = context.get_type(&type_name.node)?
+            {
+                if let (Some(parameters), Some(arguments)) = (type_parameters, type_arguments) {
+                    if arguments.len() != parameters.len() {
+                        return Err(ValidationError::WrongTypeArgumentsCount {
+                            expected: parameters.len(),
+                            actual: arguments.len(),
+                        });
+                    }
+
+                    let mut arguments = arguments.iter();
                     let mut found = false;
 
-                for (identifier, content) in &variants {
+                    for (identifier, content) in variants {
-                    if identifier == &variant.node {
+                        if identifier == variant.node {
                             found = true;
                         }
 
                         if let Some(content) = content {
-                        for r#type in content {
+                            for expected_type in &content {
                                 if let Type::Generic {
                                     concrete_type: None,
                                     ..
-                            } = r#type
+                                } = expected_type
                                 {
-                                return Err(ValidationError::FullTypeNotKnown {
+                                    arguments.next().ok_or_else(|| {
-                                    identifier: name,
+                                        ValidationError::WrongTypeArgumentsCount {
-                                    position: variant.position,
+                                            expected: content.len(),
-                                });
+                                            actual: arguments.len(),
+                                        }
+                                    })?;
                                 }
                             }
                         }
@@ -141,6 +157,7 @@ impl AbstractNode for ValueNode {
                             position: variant.position,
                         });
                     }
+                }
             } else {
                 return Err(ValidationError::EnumDefinitionNotFound {
                     identifier: type_name.node.clone(),
@@ -691,10 +708,26 @@ impl Display for ValueNode {
                 variant,
                 content,
             } => {
-                write!(f, "{}::{}", type_name.node, variant.node)?;
+                write!(f, "{}", type_name.node)?;
+
+                if let Some(types) = type_arguments {
+                    write!(f, "::<")?;
+
+                    for (index, r#type) in types.iter().enumerate() {
+                        if index > 0 {
+                            write!(f, ", ")?;
+                        }
+
+                        write!(f, "{type}")?;
+                    }
+
+                    write!(f, ">")?;
+                }
+
+                write!(f, "::{}", variant.node)?;
 
                 if let Some(expression) = content {
-                    write!(f, "{expression}")?;
+                    write!(f, "({expression})")?;
                 }
 
                 Ok(())

dust-lang/src/error.rs

@@ -181,6 +181,10 @@ pub enum ValidationError {
         identifier: Identifier,
         position: SourcePosition,
     },
+    WrongTypeArgumentsCount {
+        expected: usize,
+        actual: usize,
+    },
 }
 
 impl From<PoisonError> for ValidationError {

dust-lang/src/lib.rs

@@ -8,9 +8,9 @@ pub mod standard_library;
 pub mod value;
 
 use std::{
+    collections::{hash_map, HashMap},
     ops::Range,
     sync::{Arc, RwLock},
-    vec,
 };
 
 pub use abstract_tree::Type;
@@ -29,21 +29,24 @@ pub fn interpret(source_id: &str, source: &str) -> Result<Option<Value>, Interpr
     interpreter.run(Arc::from(source_id), Arc::from(source))
 }
 
-type Source = (Arc<str>, Arc<str>);
+/// Interpreter, lexer and parser for the Dust programming language.
-
+///
+/// You must provide the interpreter with an ID for each piece of code you pass to it. These are
+/// used to identify the source of errors and to provide more detailed error messages.
 pub struct Interpreter {
     context: Context,
-    sources: Arc<RwLock<Vec<Source>>>,
+    sources: Arc<RwLock<HashMap<Arc<str>, Arc<str>>>>,
 }
 
 impl Interpreter {
     pub fn new(context: Context) -> Self {
         Interpreter {
             context,
-            sources: Arc::new(RwLock::new(Vec::new())),
+            sources: Arc::new(RwLock::new(HashMap::new())),
         }
     }
 
+    /// Lexes the source code and returns a list of tokens.
     pub fn lex<'src>(
         &self,
         source_id: Arc<str>,
@@ -51,14 +54,14 @@ impl Interpreter {
     ) -> Result<Vec<Token<'src>>, InterpreterError> {
         let mut sources = self.sources.write().unwrap();
 
-        sources.clear();
+        sources.insert(source_id.clone(), Arc::from(source));
-        sources.push((source_id.clone(), Arc::from(source)));
 
         lex(source)
             .map(|tokens| tokens.into_iter().map(|(token, _)| token).collect())
             .map_err(|errors| InterpreterError { source_id, errors })
     }
 
+    /// Parses the source code and returns an abstract syntax tree.
     pub fn parse(
         &self,
         source_id: Arc<str>,
@@ -66,8 +69,7 @@ impl Interpreter {
     ) -> Result<AbstractTree, InterpreterError> {
         let mut sources = self.sources.write().unwrap();
 
-        sources.clear();
+        sources.insert(source_id.clone(), Arc::from(source));
-        sources.push((source_id.clone(), Arc::from(source)));
 
         parse(&lex(source).map_err(|errors| InterpreterError {
             source_id: source_id.clone(),
@@ -76,6 +78,7 @@ impl Interpreter {
         .map_err(|errors| InterpreterError { source_id, errors })
     }
 
+    /// Runs the source code and returns the result.
     pub fn run(
         &self,
         source_id: Arc<str>,
@@ -83,8 +86,7 @@ impl Interpreter {
     ) -> Result<Option<Value>, InterpreterError> {
         let mut sources = self.sources.write().unwrap();
 
-        sources.clear();
+        sources.insert(source_id.clone(), source.clone());
-        sources.push((source_id.clone(), source.clone()));
 
         let tokens = lex(source.as_ref()).map_err(|errors| InterpreterError {
             source_id: source_id.clone(),
@@ -101,12 +103,16 @@ impl Interpreter {
         Ok(value_option)
     }
 
-    pub fn sources(&self) -> vec::IntoIter<(Arc<str>, Arc<str>)> {
+    pub fn sources(&self) -> hash_map::IntoIter<Arc<str>, Arc<str>> {
         self.sources.read().unwrap().clone().into_iter()
     }
 }
 
 #[derive(Debug, PartialEq)]
+/// An error that occurred during the interpretation of a piece of code.
+///
+/// Each error has a source ID that identifies the piece of code that caused the error, and a list
+/// of errors that occurred during the interpretation of that code.
 pub struct InterpreterError {
     source_id: Arc<str>,
     errors: Vec<DustError>,
@@ -119,6 +125,7 @@ impl InterpreterError {
 }
 
 impl InterpreterError {
+    /// Converts the error into a list of user-friendly reports that can be printed to the console.
     pub fn build_reports<'a>(self) -> Vec<Report<'a, (Arc<str>, Range<usize>)>> {
         let token_color = Color::Yellow;
         let type_color = Color::Green;
@@ -281,23 +288,31 @@ impl InterpreterError {
                             builder = builder.with_help("Try specifying the type using turbofish.");
                         }
 
-                        if let Some(position) = expected_position {
+                        let actual_type_message = if let Some(position) = expected_position {
                             builder.add_label(
                                 Label::new((self.source_id.clone(), position.0..position.1))
                                     .with_message(format!(
                                         "Type {} established here.",
                                         expected.fg(type_color)
                                     )),
+                            );
+
+                            format!("Got type {} here.", actual.fg(type_color))
+                        } else {
+                            format!(
+                                "Got type {} but expected {}.",
+                                actual.fg(type_color),
+                                expected.fg(type_color)
                             )
-                        }
+                        };
 
                         builder.add_label(
                             Label::new((
                                 self.source_id.clone(),
                                 actual_position.0..actual_position.1,
                             ))
-                            .with_message(format!("Got type {} here.", actual.fg(type_color))),
+                            .with_message(actual_type_message),
-                        );
+                        )
                     }
                     ValidationError::VariableNotFound {
                         identifier,
@@ -430,6 +445,7 @@ impl InterpreterError {
                         .add_label(Label::new((self.source_id.clone(), 0..0)).with_message(reason)),
                     ValidationError::CannotUsePath(_) => todo!(),
                     ValidationError::Uninitialized => todo!(),
+                    ValidationError::WrongTypeArgumentsCount { expected, actual } => todo!(),
                 }
             }
 

dust-lang/src/parser/tests.rs

@@ -63,6 +63,27 @@ fn type_invokation() {
     );
 }
 
+#[test]
+fn enum_instance_with_type_arguments() {
+    assert_eq!(
+        parse(&lex("Foo::<int, str>::Bar(42)").unwrap()).unwrap()[0],
+        Statement::Expression(Expression::Value(
+            ValueNode::EnumInstance {
+                type_name: Identifier::new("Foo").with_position((0, 3)),
+                type_arguments: Some(vec![
+                    TypeConstructor::Raw(RawTypeConstructor::Integer.with_position((6, 9))),
+                    TypeConstructor::Raw(RawTypeConstructor::String.with_position((11, 14)))
+                ]),
+                variant: Identifier::new("Bar").with_position((17, 20)),
+                content: Some(Box::new(Expression::Value(
+                    ValueNode::Integer(42).with_position((21, 23))
+                )))
+            }
+            .with_position((0, 24))
+        ))
+    );
+}
+
 #[test]
 fn enum_instance() {
     assert_eq!(

dust-shell/src/main.rs

@@ -8,10 +8,10 @@ use colored::Colorize;
 use log::Level;
 
 use std::{
+    collections::hash_map,
     fs::read_to_string,
     io::{stderr, Write},
     sync::Arc,
-    vec,
 };
 
 use dust_lang::{context::Context, Interpreter};
@@ -81,7 +81,7 @@ fn main() {
                 for report in error.build_reports() {
                     report
                         .write_for_stdout(
-                            sources::<Arc<str>, Arc<str>, vec::IntoIter<(Arc<str>, Arc<str>)>>(
+                            sources::<Arc<str>, Arc<str>, hash_map::IntoIter<Arc<str>, Arc<str>>>(
                                 interpreter.sources(),
                             ),
                             stderr(),