fixed closures

interpreter/build.rs

@@ -37,12 +37,8 @@ fn generate_tests() {
     for lox_file in glob("tests/lox/**/*.lox").unwrap() {
         let lox_file = lox_file.unwrap();
 
-        println!("found lox file: {}", lox_file.to_str().unwrap());
-
         output += &build_test_case(lox_file);
     }
 
-    println!("{output}");
-
     std::fs::write("tests/all_tests.rs", output).unwrap();
 }

interpreter/src/environment.rs

@@ -205,13 +205,13 @@ impl<'a> Environment<'a> {
         name: &str,
         level: usize,
     ) -> Result<HeapedValue, RuntimeError> {
-        if level < self.scopes().len() {
+        assert!(level < self.scopes().len());
+
         let scope = self.scopes_mut().iter_mut().rev().nth(level).unwrap();
 
         if let Some(scoped_value) = scope.get_mut(name) {
             return Ok(scoped_value.heapified());
         }
-        }
 
         panic!("Name not defined not caught by resolver");
 
@@ -252,20 +252,10 @@ impl<'a> Environment<'a> {
 
         for (name, level) in closure_vars {
             // special injected variables
-            if &**name == "this" || &**name == "super" {
+            if name == "this" || name == "super" {
                 continue;
             }
 
-            // let heap_value = self
-            //     .scopes()
-            //     .iter()
-            //     .rev()
-            //     .nth(*level)
-            //     .expect("Closure variable got resolved to level that doesn't exist")
-            //     .get(name)
-            //     .expect("Closure variable was resolved, but could not be found")
-            //     .clone();
-
             let heap_value = self.get_local_heaped(name, *level).unwrap();
 
             let name = name.to_owned();

interpreter/src/function.rs

@@ -15,7 +15,7 @@ pub struct LoxFunction {
     name: SmolStr,
     closure: ClosureScope,
     param_names: Vec<SmolStr>,
-    body: Box<Stmt>,
+    body: Stmt,
 }
 
 impl LoxFunction {
@@ -26,7 +26,6 @@ impl LoxFunction {
         body: Stmt,
     ) -> Rc<Self> {
         let name = name.into();
-        let body = Box::new(body);
         let fun = LoxFunction {
             name,
             closure,

interpreter/src/interpreter.rs

@@ -182,12 +182,19 @@ impl Eval for Expr {
                 param_names,
                 closure_vars,
                 body,
-            } => Ok(Value::function(LoxFunction::new(
+            } => {
-                name.clone(),
+                let name = name.clone();
-                env.collect_closure(closure_vars),
+                let closure = env.collect_closure(closure_vars);
-                param_names.clone(),
+                let param_names = param_names.clone();
-                body.as_ref().clone(),
+                let body = body.as_ref().clone();
-            ))),
+
+                Ok(Value::function(LoxFunction::new(
+                    name,
+                    closure,
+                    param_names,
+                    body,
+                )))
+            }
             Expr::Class {
                 superclass,
                 name,
@@ -315,7 +322,7 @@ pub fn call_fun(fun: Rc<LoxFunction>, env: &mut Environment) -> EvalResult<Value
 
     env.enter_scope()?;
 
-    env.define(fun.name(), Value::Function(fun.clone()));
+    env.define(fun.name(), Value::Function(Rc::clone(&fun)));
 
     env.insert_closure(fun.closure().clone());
 

interpreter/src/lox_std.rs

@@ -54,7 +54,7 @@ fn print_globals() -> LoxExternFunction {
         globals.sort_by_key(|&(name, _value)| name);
 
         for (name, value) in globals {
-            println!("{name}: {value}");
+            println!("{name} = {value}");
         }
 
         Ok(Value::Nil)

interpreter/src/resolver/_resolver.rs

@@ -8,7 +8,7 @@ use crate::{LoxError, ResolverError};
 /*====================================================================================================================*/
 
 type ResolverScope = FxHashMap<SmolStr, ResolveStatus>;
-type ResolverFrame = Vec<ResolverScope>;
+// type ResolverFrame = Vec<ResolverScope>;
 
 type ResolverResult<T> = Result<T, ResolverError>;
 
@@ -20,6 +20,22 @@ enum ResolveStatus {
     Defined,
 }
 
+#[derive(Debug, Default)]
+struct ResolverFrame {
+    scopes: Vec<ResolverScope>,
+
+    closure_vars: FxHashMap<SmolStr, usize>,
+}
+
+impl ResolverFrame {
+    fn new() -> Self {
+        ResolverFrame {
+            scopes: vec![ResolverScope::default()],
+            closure_vars: Default::default(),
+        }
+    }
+}
+
 /*====================================================================================================================*/
 
 pub fn resolve(statement: &mut Stmt, runtime: &mut Runtime) -> Result<(), LoxError> {
@@ -35,10 +51,10 @@ pub fn resolve(statement: &mut Stmt, runtime: &mut Runtime) -> Result<(), LoxErr
 #[derive(Debug)]
 struct Resolver {
     global_scope: ResolverScope,
+
     // local_scopes: Vec<ResolverScope>,
     frames: Vec<ResolverFrame>,
-
+    // closure_vars: FxHashMap<SmolStr, usize>,
-    closure_vars: FxHashMap<SmolStr, usize>,
 }
 
 impl Resolver {
@@ -51,19 +67,35 @@ impl Resolver {
 
         Resolver {
             global_scope,
-            frames: vec![ResolverFrame::new()],
+            frames: vec![ResolverFrame::default()],
-            closure_vars: FxHashMap::default(),
+            // closure_vars: FxHashMap::default(),
         }
     }
 
-    fn local_scopes(&self) -> &ResolverFrame {
+    fn frame(&self) -> &ResolverFrame {
         self.frames.last().unwrap()
     }
 
-    fn local_scopes_mut(&mut self) -> &mut ResolverFrame {
+    fn frame_mut(&mut self) -> &mut ResolverFrame {
         self.frames.last_mut().unwrap()
     }
 
+    fn local_scopes(&self) -> &[ResolverScope] {
+        &self.frame().scopes
+    }
+
+    fn local_scopes_mut(&mut self) -> &mut Vec<ResolverScope> {
+        &mut self.frame_mut().scopes
+    }
+
+    /* fn closure_vars(&self) -> &FxHashMap<SmolStr, usize> {
+        &self.frame().closure_vars
+    } */
+
+    fn closure_vars_mut(&mut self) -> &mut FxHashMap<SmolStr, usize> {
+        &mut self.frame_mut().closure_vars
+    }
+
     fn enter_scope(&mut self) {
         self.local_scopes_mut().push(ResolverScope::default());
     }
@@ -75,7 +107,7 @@ impl Resolver {
     }
 
     fn push_frame(&mut self) {
-        self.frames.push(vec![ResolverScope::default()]);
+        self.frames.push(ResolverFrame::new());
     }
 
     fn pop_frame(&mut self) {
@@ -119,39 +151,51 @@ impl Resolver {
         }
     }
 
-    fn resolve_var(&mut self, name: &str) -> ResolverResult<Expr> {
+    // try to recursively resolve closure variable by descending through the frames until the
-        let mut level = 0;
+    // variable is found and then inserting closures at every needed level
+    fn resolve_closure(&mut self, name: SmolStr, frame_lvl: usize) -> Option<usize> {
+        let frame = &mut self.frames[frame_lvl];
 
+        for (level, scope) in frame.scopes.iter().rev().enumerate() {
+            if scope.contains_key(&name) {
+                return Some(level);
+            }
+        }
+
+        if frame_lvl == 0 {
+            return None;
+        }
+
+        if let Some(level) = self.resolve_closure(name.clone(), frame_lvl - 1) {
+            let frame = &mut self.frames[frame_lvl];
+
+            frame.closure_vars.insert(name, level);
+            Some(frame.scopes.len() - 1)
+        } else {
+            None
+        }
+    }
+
+    fn resolve_var(&mut self, name: SmolStr) -> ResolverResult<Expr> {
         // resolve normal local variable
-        for scope in self.local_scopes().iter().rev() {
+        for (level, scope) in self.local_scopes().iter().rev().enumerate() {
-            if scope.contains_key(name) {
+            if scope.contains_key(&name) {
                 return Ok(Expr::local_variable(name, level));
             }
-            level += 1;
         }
 
-        // resolve closure variable
+        // if we have more than one frame: look for closure variable
-        for frame in self.frames.iter().rev().skip(1) {
+        if self.frames.len() > 1 {
-            for scope in frame.iter().rev() {
+            //try to resolve closure variable up from one frame down
-                if scope.contains_key(name) {
+            if let Some(level) = self.resolve_closure(name.clone(), self.frames.len() - 2) {
-                    if !self.closure_vars.contains_key(name) {
+                self.closure_vars_mut().insert(name.clone(), level);
-                        // the level at which the closed-over variable will be collected from
-                        // from the perspective of the parameter/closure scope i.e. the outmost of the function
-                        self.closure_vars
-                            .insert(name.into(), level - self.local_scopes().len());
-                    }
 
-                    // distance from actual variable refernce to parameter/closure scope
+                return Ok(Expr::local_variable(name, self.local_scopes().len() - 1));
-                    let level = self.local_scopes().len() - 1;
-
-                    return Ok(Expr::local_variable(name, level));
-                }
-                level += 1;
             }
         }
 
         // resolve global variable
-        if self.global_scope.contains_key(name) {
+        if self.global_scope.contains_key(&name) {
             return Ok(Expr::global_variable(name));
         }
 
@@ -161,8 +205,6 @@ impl Resolver {
             return Err(ResolverError::SuperOutsideMethod);
         }
 
-        let name = name.into();
-
         Err(ResolverError::UnresolvableVariable { name })
     }
 
@@ -243,7 +285,7 @@ impl Resolver {
                     return Err(ResolverError::VarInOwnInitializer { name });
                 }
 
-                *expr = self.resolve_var(name)?;
+                *expr = self.resolve_var(name.clone())?;
 
                 Ok(())
             }
@@ -260,7 +302,7 @@ impl Resolver {
                 let target = target.as_mut();
 
                 if let Expr::Variable { name } = target {
-                    *target = self.resolve_var(name)?;
+                    *target = self.resolve_var(name.clone())?;
                 } else {
                     panic!("Invalid assignment target {target}");
                 }
@@ -298,7 +340,7 @@ impl Resolver {
                 closure_vars,
                 body,
             } => {
-                let old_closure_names = std::mem::take(&mut self.closure_vars);
+                // let old_closure_names = std::mem::take(&mut self.closure_vars);
 
                 self.push_frame();
 
@@ -314,12 +356,12 @@ impl Resolver {
 
                 self.resolve_stmt(body)?;
 
+                let closure_names = std::mem::take(self.closure_vars_mut());
+
                 self.pop_frame();
 
-                let closure_names = std::mem::replace(&mut self.closure_vars, old_closure_names);
+                for (var_name, level) in closure_names {
-
+                    closure_vars.push((var_name, level));
-                for closure_var in closure_names {
-                    closure_vars.push(closure_var);
                 }
 
                 Ok(())
@@ -344,7 +386,7 @@ impl Resolver {
                 self.declare("this").unwrap();
 
                 if superclass.is_some() {
-                    // this should never fail either! same as `this`
+                    // this should never fail either! same reason as `this`
                     self.declare("super").unwrap();
                 }
 
@@ -357,7 +399,7 @@ impl Resolver {
                 Ok(())
             }
             Expr::This => {
-                *expr = self.resolve_var("this")?;
+                *expr = self.resolve_var("this".into())?;
                 Ok(())
             }
             Expr::Super {