Add new tests for type checking

src/abstract_tree/assignment.rs

@@ -68,17 +68,30 @@ impl AbstractTree for Assignment {
 
             match operator {
                 AssignmentOperator::Equal => {
-                    type_definition.inner().check(&statement_type)?;
+                    type_definition
+                        .inner()
+                        .check(&statement_type)
+                        .map_err(|error| error.at_node(statement_node, source))?;
                 }
                 AssignmentOperator::PlusEqual => {
                     let identifier_type = identifier.expected_type(context)?;
 
                     if let Type::List(item_type) = type_definition.inner() {
-                        item_type.check(&identifier_type)?;
+                        item_type
-                        item_type.check(&statement_type)?;
+                            .check(&identifier_type)
+                            .map_err(|error| error.at_node(identifier_node, source))?;
+                        item_type
+                            .check(&statement_type)
+                            .map_err(|error| error.at_node(statement_node, source))?;
                     } else {
-                        type_definition.inner().check(&identifier_type)?;
+                        type_definition
-                        type_definition.inner().check(&statement_type)?;
+                            .inner()
+                            .check(&identifier_type)
+                            .map_err(|error| error.at_node(identifier_node, source))?;
+                        type_definition
+                            .inner()
+                            .check(&statement_type)
+                            .map_err(|error| error.at_node(statement_node, source))?;
                     }
                 }
                 AssignmentOperator::MinusEqual => todo!(),
@@ -118,8 +131,6 @@ impl AbstractTree for Assignment {
         };
 
         if let Some(type_defintion) = &self.type_definition {
-            type_defintion.inner().check(&new_value.r#type())?;
-
             context.set(key.clone(), new_value, Some(type_defintion.inner().clone()))?;
         } else {
             context.set(key.clone(), new_value, None)?;
@@ -135,7 +146,7 @@ impl AbstractTree for Assignment {
 
 #[cfg(test)]
 mod tests {
-    use crate::{evaluate, Error, List, Value};
+    use crate::{evaluate, Error, List, Type, Value};
 
     #[test]
     fn simple_assignment() {
@@ -167,18 +178,19 @@ mod tests {
 
     #[test]
     fn list_add_wrong_type() {
-        let test = evaluate(
+        let result = evaluate(
             "
             x <[str]> = []
             x += 1
             ",
-        )
+        );
-        .unwrap_err();
 
-        match test {
+        assert_eq!(
-            Error::WithContext { .. } => {}
+            Err(Error::TypeCheck {
-            Error::TypeCheck { .. } => {}
+                expected: Type::String,
-            _ => panic!(),
+                actual: Type::Integer
-        }
+            }),
+            result
+        )
     }
 }

src/abstract_tree/function_call.rs

@@ -49,11 +49,7 @@ impl AbstractTree for FunctionCall {
 
                     expected_type
                         .check(&expression_type)
-                        .map_err(|error| Error::WithContext {
+                        .map_err(|error| error.at_node(child, source))?;
-                            error: Box::new(error),
-                            location: child.start_position(),
-                            source: source[child.byte_range()].to_string(),
-                        })?;
                 }
 
                 arguments.push(expression);

src/abstract_tree/type_definition.rs

@@ -83,7 +83,14 @@ impl Type {
             | (Type::Float, Type::Number)
             | (Type::String, Type::String) => Ok(()),
             (Type::List(self_item_type), Type::List(other_item_type)) => {
-                self_item_type.check(&other_item_type)
+                if self_item_type.check(&other_item_type).is_err() {
+                    Err(Error::TypeCheck {
+                        expected: self.clone(),
+                        actual: other.clone(),
+                    })
+                } else {
+                    Ok(())
+                }
             }
             (
                 Type::Function {
@@ -100,9 +107,7 @@ impl Type {
                     .zip(other_parameter_types.iter());
 
                 for (self_parameter_type, other_parameter_type) in parameter_type_pairs {
-                    let check = self_parameter_type.check(&other_parameter_type);
+                    if self_parameter_type.check(&other_parameter_type).is_err() {
-
-                    if let Err(Error::TypeCheck { .. }) = check {
                         return Err(Error::TypeCheck {
                             expected: self.clone(),
                             actual: other.clone(),
@@ -110,16 +115,14 @@ impl Type {
                     }
                 }
 
-                let check = self_return_type.check(other_return_type);
+                if self_return_type.check(other_return_type).is_err() {
-
+                    Err(Error::TypeCheck {
-                if let Err(Error::TypeCheck { .. }) = check {
-                    return Err(Error::TypeCheck {
                         expected: self.clone(),
                         actual: other.clone(),
-                    });
+                    })
+                } else {
+                    Ok(())
                 }
-
-                Ok(())
             }
             _ => Err(Error::TypeCheck {
                 expected: self.clone(),
@@ -229,3 +232,49 @@ impl Display for Type {
         }
     }
 }
+
+#[cfg(test)]
+mod tests {
+    use crate::evaluate;
+
+    use super::*;
+
+    #[test]
+    fn simple_type_check() {
+        let result = evaluate("x <bool> = 1");
+
+        assert_eq!(
+            Err(Error::TypeCheck {
+                expected: Type::Boolean,
+                actual: Type::Integer
+            }),
+            result
+        );
+    }
+
+    #[test]
+    fn callback_type_check() {
+        let result = evaluate(
+            "
+            x = (fn cb <() -> bool>) <bool> {
+                (cb)
+            }
+            (x (fn) <int> { 1 })
+            ",
+        );
+
+        assert_eq!(
+            Err(Error::TypeCheck {
+                expected: Type::Function {
+                    parameter_types: vec![],
+                    return_type: Box::new(Type::Boolean),
+                },
+                actual: Type::Function {
+                    parameter_types: vec![],
+                    return_type: Box::new(Type::Integer),
+                },
+            }),
+            result
+        );
+    }
+}

src/error.rs

@@ -156,11 +156,11 @@ pub enum Error {
 }
 
 impl Error {
-    pub fn with_context(self, location: Point, source: String) -> Self {
+    pub fn at_node(self, node: Node, source: &str) -> Self {
         Error::WithContext {
             error: Box::new(self),
-            location,
+            location: node.start_position(),
-            source,
+            source: source[node.byte_range()].to_string(),
         }
     }
 

src/value/function.rs

@@ -50,16 +50,6 @@ impl Function {
     pub fn call(&self, arguments: &[Expression], source: &str, context: &Map) -> Result<Value> {
         let function_context = Map::clone_from(context)?;
 
-        let (parameter_types, return_type) = if let Type::Function {
-            parameter_types,
-            return_type,
-        } = &self.r#type
-        {
-            (parameter_types, return_type)
-        } else {
-            todo!()
-        };
-
         if self.parameters.len() != arguments.len() {
             return Err(Error::ExpectedArgumentAmount {
                 function_name: "",
@@ -68,27 +58,18 @@ impl Function {
             });
         }
 
-        let parameter_argument_pairs = self
+        let parameter_argument_pairs = self.parameters.iter().zip(arguments.iter());
-            .parameters
-            .iter()
-            .zip(parameter_types.iter())
-            .zip(arguments.iter());
 
-        for ((identifier, argument_type), expression) in parameter_argument_pairs {
+        for (identifier, expression) in parameter_argument_pairs {
             let value = expression.run(source, context)?;
-            let value_type = value.r#type();
-
-            argument_type.check(&value_type)?;
 
             let key = identifier.inner().clone();
 
-            function_context.set(key, value, Some(value_type))?;
+            function_context.set(key, value, None)?;
         }
 
         let return_value = self.body.run(source, &function_context)?;
 
-        return_type.check(&return_value.r#type())?;
-
         Ok(return_value)
     }
 }

src/value/map.rs

@@ -53,10 +53,6 @@ impl Map {
             .write()?
             .insert(key, (value, value_type.clone()));
 
-        if let Some((_previous_value, previous_type)) = previous.clone() {
-            previous_type.check(&value_type)?;
-        }
-
         Ok(previous)
     }
 }

tree-sitter-dust/corpus/functions.txt

@@ -114,3 +114,52 @@ Complex Function Call
                 (expression
                   (value
                     (integer)))))))))))
+
+================================================================================
+Callback Function Call
+================================================================================
+
+x = (fn cb <() -> bool>) <bool> {
+    (cb)
+}
+
+(x (fn) <bool> { true })
+
+--------------------------------------------------------------------------------
+
+(root
+  (statement
+    (assignment
+      (identifier)
+      (assignment_operator)
+      (statement
+        (expression
+          (value
+            (function
+              (identifier)
+              (type_definition
+                (type
+                  (type)))
+              (type_definition
+                (type))
+              (block
+                (statement
+                  (expression
+                    (function_call
+                      (expression
+                        (identifier))))))))))))
+  (statement
+    (expression
+      (function_call
+        (expression
+          (identifier))
+        (expression
+          (value
+            (function
+              (type_definition
+                (type))
+              (block
+                (statement
+                  (expression
+                    (value
+                      (boolean))))))))))))