Fix inheritance; Add a test

dust-lang/src/context.rs

@@ -13,6 +13,7 @@ use crate::{
     error::{PoisonError, ValidationError},
     identifier::Identifier,
     standard_library::core_context,
+    value::ValueInner,
     Value,
 };
 
@@ -55,11 +56,37 @@ impl Context {
         if let (Ok(mut self_variables), Ok(other_variables)) =
             (get_self_variables, get_other_variables)
         {
-            self_variables.extend(other_variables.iter().map(|(identifier, data)| {
+            self_variables.extend(other_variables.iter().filter_map(
+                |(identifier, (variable, usage, position))| {
                     trace!("Inheriting {identifier}");
 
-                (identifier.clone(), data.clone())
+                    if let VariableData::Type(r#type) = variable {
-            }));
+                        match r#type {
+                            Type::Enum { .. } | Type::Function { .. } | Type::Structure { .. } => {
+                                return Some((
+                                    identifier.clone(),
+                                    (variable.clone(), usage.clone(), *position),
+                                ))
+                            }
+                            _ => {}
+                        }
+                    }
+
+                    if let VariableData::Value(value) = variable {
+                        match value.inner().as_ref() {
+                            ValueInner::BuiltInFunction(_) | ValueInner::Function(_) => {
+                                return Some((
+                                    identifier.clone(),
+                                    (variable.clone(), usage.clone(), *position),
+                                ))
+                            }
+                            _ => {}
+                        }
+                    }
+
+                    None
+                },
+            ));
         }
 
         Ok(())

dust-lang/tests/functions.rs

@@ -1,5 +1,27 @@
 use dust_lang::*;
 
+#[test]
+fn function_scope() {
+    assert_eq!(
+        interpret(
+            "test",
+            "
+            x = 2
+            
+            foo = fn () -> int {
+                x = 42
+                x
+            }
+            
+            x = 1
+
+            foo()        
+            "
+        ),
+        Ok(Some(Value::integer(42)))
+    );
+}
+
 #[test]
 fn function_call_with_type_argument() {
     assert_eq!(
@@ -74,14 +96,16 @@ fn recursion() {
             "test",
             "
             fib = fn (i: int) -> int {
-            	if i <= 1 {
+            	if i < 0 {
-            		1
+                    0
+                } else if i <= 1 {
+            		i
             	} else {
             		fib(i - 1) + fib(i - 2)
             	}
             }
 
-            fib(8)
+            fib(4)
             "
         ),
         Ok(Some(Value::integer(13)))