Fix type checking bug

src/abstract_tree/function_call.rs

@@ -3,8 +3,8 @@ use serde::{Deserialize, Serialize};
 use crate::{
     built_in_functions::Callable,
     error::{RuntimeError, SyntaxError, ValidationError},
-    AbstractTree, Context, Expression, Format, FunctionExpression, SourcePosition, SyntaxNode,
+    AbstractTree, Context, Expression, Format, Function, FunctionExpression, SourcePosition,
-    Type, Value,
+    SyntaxNode, Type, Value,
 };
 
 /// A function being invoked and the arguments it is being passed.
@@ -94,17 +94,16 @@ impl AbstractTree for FunctionCall {
     fn validate(&self, _source: &str, context: &Context) -> Result<(), ValidationError> {
         let function_expression_type = self.function_expression.expected_type(context)?;
 
-        let parameter_types = match function_expression_type {
+        let parameter_types = if let Type::Function {
-            Type::Function {
             parameter_types, ..
-            } => parameter_types,
+        } = function_expression_type
-            Type::Any => return Ok(()),
+        {
-            _ => {
+            parameter_types
+        } else {
             return Err(ValidationError::TypeCheckExpectedFunction {
                 actual: function_expression_type,
                 position: self.syntax_position,
             });
-            }
         };
 
         if self.arguments.len() != parameter_types.len() {
@@ -156,7 +155,7 @@ impl AbstractTree for FunctionCall {
         let function = value.as_function()?;
 
         match function {
-            crate::Function::BuiltIn(built_in_function) => {
+            Function::BuiltIn(built_in_function) => {
                 let mut arguments = Vec::with_capacity(self.arguments.len());
 
                 for expression in &self.arguments {
@@ -167,7 +166,7 @@ impl AbstractTree for FunctionCall {
 
                 built_in_function.call(&arguments, source, &self.context)
             }
-            crate::Function::ContextDefined(function_node) => {
+            Function::ContextDefined(function_node) => {
                 let parameter_expression_pairs =
                     function_node.parameters().iter().zip(self.arguments.iter());
 

src/abstract_tree/function_node.rs

@@ -109,13 +109,19 @@ impl AbstractTree for FunctionNode {
         Ok(self.r#type().clone())
     }
 
-    fn validate(&self, source: &str, context: &Context) -> Result<(), ValidationError> {
+    fn validate(&self, source: &str, _context: &Context) -> Result<(), ValidationError> {
         if let Type::Function {
-            parameter_types: _,
+            parameter_types,
             return_type,
         } = &self.r#type
         {
-            let actual = self.body.expected_type(context)?;
+            let validation_context = Context::new();
+
+            for (parameter, r#type) in self.parameters.iter().zip(parameter_types.iter()) {
+                validation_context.set_type(parameter.inner().clone(), r#type.clone())?;
+            }
+
+            let actual = self.body.expected_type(&validation_context)?;
 
             if !return_type.accepts(&actual) {
                 return Err(ValidationError::TypeCheck {
@@ -125,7 +131,7 @@ impl AbstractTree for FunctionNode {
                 });
             }
 
-            self.body.validate(source, context)?;
+            self.body.validate(source, &validation_context)?;
 
             Ok(())
         } else {

src/context.rs

@@ -53,13 +53,11 @@ impl Context {
     pub fn get_value(&self, key: &str) -> Result<Option<Value>, RwLockError> {
         if let Some(value_data) = self.inner.read()?.get(key) {
             if let ValueData::Value { inner, .. } = value_data {
-                Ok(Some(inner.clone()))
+                return Ok(Some(inner.clone()));
-            } else {
-                Ok(None)
             }
-        } else {
-            Ok(None)
         }
+
+        Ok(None)
     }
 
     pub fn get_type(&self, key: &str) -> Result<Option<Type>, RwLockError> {

src/main.rs

@@ -116,59 +116,59 @@ fn main() {
     }
 }
 
-struct DustHighlighter {
+// struct DustHighlighter {
-    context: Context,
+//     context: Context,
-}
+// }
 
-impl DustHighlighter {
+// impl DustHighlighter {
-    fn new(context: Context) -> Self {
+//     fn new(context: Context) -> Self {
-        Self { context }
+//         Self { context }
-    }
+//     }
-}
+// }
 
-const HIGHLIGHT_TERMINATORS: [char; 8] = [' ', ':', '(', ')', '{', '}', '[', ']'];
+// const HIGHLIGHT_TERMINATORS: [char; 8] = [' ', ':', '(', ')', '{', '}', '[', ']'];
 
-impl Highlighter for DustHighlighter {
+// impl Highlighter for DustHighlighter {
-    fn highlight(&self, line: &str, _cursor: usize) -> reedline::StyledText {
+//     fn highlight(&self, line: &str, _cursor: usize) -> reedline::StyledText {
-        let mut styled = StyledText::new();
+//         let mut styled = StyledText::new();
 
-        for word in line.split_inclusive(&HIGHLIGHT_TERMINATORS) {
+//         for word in line.split_inclusive(&HIGHLIGHT_TERMINATORS) {
-            let mut word_is_highlighted = false;
+//             let mut word_is_highlighted = false;
 
-            for key in self.context.inner().unwrap().keys() {
+//             for key in self.context.inner().unwrap().keys() {
-                if key == &word {
+//                 if key == &word {
-                    styled.push((Style::new().bold(), word.to_string()));
+//                     styled.push((Style::new().bold(), word.to_string()));
-                }
+//                 }
 
-                word_is_highlighted = true;
+//                 word_is_highlighted = true;
-            }
+//             }
 
-            for built_in_value in built_in_values() {
+//             for built_in_value in built_in_values() {
-                if built_in_value.name() == word {
+//                 if built_in_value.name() == word {
-                    styled.push((Style::new().bold(), word.to_string()));
+//                     styled.push((Style::new().bold(), word.to_string()));
-                }
+//                 }
 
-                word_is_highlighted = true;
+//                 word_is_highlighted = true;
-            }
+//             }
 
-            if word_is_highlighted {
+//             if word_is_highlighted {
-                let final_char = word.chars().last().unwrap();
+//                 let final_char = word.chars().last().unwrap();
 
-                if HIGHLIGHT_TERMINATORS.contains(&final_char) {
+//                 if HIGHLIGHT_TERMINATORS.contains(&final_char) {
-                    let mut terminator_style = Style::new();
+//                     let mut terminator_style = Style::new();
 
-                    terminator_style.foreground = Some(Color::Cyan);
+//                     terminator_style.foreground = Some(Color::Cyan);
 
-                    styled.push((terminator_style, final_char.to_string()));
+//                     styled.push((terminator_style, final_char.to_string()));
-                }
+//                 }
-            } else {
+//             } else {
-                styled.push((Style::new(), word.to_string()));
+//                 styled.push((Style::new(), word.to_string()));
-            }
+//             }
-        }
+//         }
 
-        styled
+//         styled
-    }
+//     }
-}
+// }
 
 struct StarshipPrompt {
     left: String,
@@ -367,7 +367,6 @@ fn run_shell(context: Context) -> Result<(), Error> {
     let mut line_editor = Reedline::create()
         .with_edit_mode(edit_mode)
         .with_history(history)
-        .with_highlighter(Box::new(DustHighlighter::new(context.clone())))
         .with_hinter(hinter)
         .use_kitty_keyboard_enhancement(true)
         .with_completer(Box::new(completer))

tests/types.rs

@@ -32,8 +32,21 @@ fn argument_count_check() {
     let result = interpret(source);
 
     assert_eq!(
-        "Expected 1 arguments, but got 0. Occured at (5, 12) to (5, 17). Source: foo()",
+        Err(Error::Validation(
-        result.unwrap_err().to_string()
+            ValidationError::ExpectedFunctionArgumentAmount {
+                expected: 1,
+                actual: 0,
+                position: SourcePosition {
+                    start_byte: 81,
+                    end_byte: 86,
+                    start_row: 5,
+                    start_column: 12,
+                    end_row: 5,
+                    end_column: 17
+                }
+            }
+        )),
+        result
     )
 }