Add and pass test

src/abstract_tree/assignment.rs

@@ -29,10 +29,14 @@ impl<'src> AbstractTree for Assignment<'src> {
     }
 
     fn validate(&self, context: &Context) -> Result<(), ValidationError> {
-        if let Some(expected) = &self.r#type {
         let statement_type = self.statement.expected_type(context)?;
 
+        if let Some(expected) = &self.r#type {
             expected.check(&statement_type)?;
+
+            context.set_type(self.identifier.clone(), expected.clone())?;
+        } else {
+            context.set_type(self.identifier.clone(), statement_type)?;
         }
 
         Ok(())
@@ -41,7 +45,7 @@ impl<'src> AbstractTree for Assignment<'src> {
     fn run(self, context: &Context) -> Result<Value, RuntimeError> {
         let value = self.statement.run(context)?;
 
-        context.set(self.identifier, value)?;
+        context.set_value(self.identifier, value)?;
 
         Ok(Value::none())
     }
@@ -69,7 +73,7 @@ mod tests {
         .unwrap();
 
         assert_eq!(
-            context.get(&Identifier::new("foobar")),
+            context.get_value(&Identifier::new("foobar")),
             Ok(Some(Value::integer(42)))
         )
     }

src/abstract_tree/identifier.rs

@@ -26,15 +26,15 @@ impl Identifier {
 
 impl AbstractTree for Identifier {
     fn expected_type(&self, context: &Context) -> Result<Type, ValidationError> {
-        if let Some(value) = context.get(self)? {
+        if let Some(r#type) = context.get_type(self)? {
-            Ok(value.r#type())
+            Ok(r#type)
         } else {
             Err(ValidationError::VariableNotFound(self.clone()))
         }
     }
 
     fn validate(&self, context: &Context) -> Result<(), ValidationError> {
-        if let Some(_) = context.get(self)? {
+        if let Some(_) = context.get_data(self)? {
             Ok(())
         } else {
             Err(ValidationError::VariableNotFound(self.clone()))
@@ -42,7 +42,10 @@ impl AbstractTree for Identifier {
     }
 
     fn run(self, context: &Context) -> Result<Value, RuntimeError> {
-        let value = context.get(&self)?.unwrap_or_else(Value::none).clone();
+        let value = context
+            .get_value(&self)?
+            .unwrap_or_else(Value::none)
+            .clone();
 
         Ok(value)
     }

src/context.rs

@@ -3,10 +3,20 @@ use std::{
     sync::{Arc, RwLock},
 };
 
-use crate::{abstract_tree::Identifier, error::RwLockPoisonError, Value};
+use crate::{
+    abstract_tree::{Identifier, Type},
+    error::RwLockPoisonError,
+    Value,
+};
 
 pub struct Context {
-    inner: Arc<RwLock<BTreeMap<Identifier, Value>>>,
+    inner: Arc<RwLock<BTreeMap<Identifier, ValueData>>>,
+}
+
+#[derive(Clone, Debug)]
+pub enum ValueData {
+    Type(Type),
+    Value(Value),
 }
 
 impl Context {
@@ -16,20 +26,47 @@ impl Context {
         }
     }
 
-    pub fn with_values(values: BTreeMap<Identifier, Value>) -> Self {
+    pub fn with_data(data: BTreeMap<Identifier, ValueData>) -> Self {
         Self {
-            inner: Arc::new(RwLock::new(values)),
+            inner: Arc::new(RwLock::new(data)),
         }
     }
 
-    pub fn get(&self, identifier: &Identifier) -> Result<Option<Value>, RwLockPoisonError> {
+    pub fn get_data(
-        let value = self.inner.read()?.get(identifier).cloned();
+        &self,
-
+        identifier: &Identifier,
-        Ok(value)
+    ) -> Result<Option<ValueData>, RwLockPoisonError> {
+        Ok(self.inner.read()?.get(identifier).cloned())
     }
 
-    pub fn set(&self, identifier: Identifier, value: Value) -> Result<(), RwLockPoisonError> {
+    pub fn get_type(&self, identifier: &Identifier) -> Result<Option<Type>, RwLockPoisonError> {
-        self.inner.write()?.insert(identifier, value);
+        if let Some(ValueData::Type(r#type)) = self.inner.read()?.get(identifier) {
+            Ok(Some(r#type.clone()))
+        } else {
+            Ok(None)
+        }
+    }
+
+    pub fn get_value(&self, identifier: &Identifier) -> Result<Option<Value>, RwLockPoisonError> {
+        if let Some(ValueData::Value(value)) = self.inner.read()?.get(identifier) {
+            Ok(Some(value.clone()))
+        } else {
+            Ok(None)
+        }
+    }
+
+    pub fn set_type(&self, identifier: Identifier, r#type: Type) -> Result<(), RwLockPoisonError> {
+        self.inner
+            .write()?
+            .insert(identifier, ValueData::Type(r#type));
+
+        Ok(())
+    }
+
+    pub fn set_value(&self, identifier: Identifier, value: Value) -> Result<(), RwLockPoisonError> {
+        self.inner
+            .write()?
+            .insert(identifier, ValueData::Value(value));
 
         Ok(())
     }

src/lib.rs

@@ -12,6 +12,13 @@ use lexer::lex;
 pub use parser::{parse, parser, DustParser};
 pub use value::Value;
 
+pub fn interpret(source: &str) -> Result<Value, Vec<Error>> {
+    let context = Context::new();
+    let mut interpreter = Interpreter::new(context);
+
+    interpreter.run(source)
+}
+
 pub struct Interpreter {
     context: Context,
 }

tests/variables.rs

@@ -0,0 +1,9 @@
+use dust_lang::*;
+
+#[test]
+fn set_and_get_variable() {
+    assert_eq!(
+        interpret("foobar = true foobar"),
+        Ok(Value::boolean(true))
+    );
+}