fix: LSP补全触发和语法高亮更新

- completion_provider 注册 a-z A-Z _ . 为触发字符，解决 Copilot 拦截补全问题
- 语法高亮新增 try catch finally throw 关键字

Co-Authored-By: Claude <noreply@anthropic.com>

README.md

@@ -1,6 +1,6 @@
 # Aster
 
-Aster 是一门使用 Rust 编写的动态类型脚本语言解释器，基于树遍历（tree-walker）实现。无外部依赖，纯标准库。
+Aster 是一门使用 Rust 编写的动态类型脚本语言，采用**基于栈的字节码 VM** 执行。无外部依赖，纯标准库。
 
 ## 快速开始
 
@@ -84,6 +84,21 @@ while (true) {
     if (condition) { break; }
     if (skip) { continue; }
 }
+
+// for-in 遍历（数组 / 字符串）
+for (let item in [1, 2, 3]) {
+    print(item);
+}
+```
+
+### 模块系统
+
+```js
+// 加载并执行外部脚本，返回模块导出的对象
+let math = require("math.ast");
+print(math.add(3, 4));
+
+// 第二次 require 同一文件会返回缓存的对象（支持循环引用）
 ```
 
 ### 函数与闭包
@@ -144,23 +159,25 @@ let t = os.clock();           // 模块化调用
 ## 架构
 
 ```
-源码文本 → Lexer → Tokens → Parser → AST → Interpreter → 输出
+源码文本 → Lexer → Tokens → Parser → AST → Compiler → Bytecode → VM → 输出
 ```
 
 | 模块 | 职责 |
 |------|------|
-| `lexer/` | 词法分析。`Lexer::tokenize()` 将源码转为 `(Vec<Token>, Vec<Error>)`，Token 记录行列号用于错误报告，支持 `//` 单行注释 |
+| `lexer/` | 词法分析。`Lexer::tokenize()` 将源码转为 `(Vec<Token>, Vec<Error>)`，Token 记录行列号用于错误报告，支持 `//` 单行注释和 `/* */` 块注释 |
 | `parser/` | 递归下降 + Pratt 解析器。`Parser::parse()` 返回 `(Vec<Stmt>, Vec<Error>)`，遇到语法错误通过 `synchronize()` 跳过至下一条语句边界继续解析 |
 | `ast/` | AST 节点定义。`Expr`（表达式）涵盖字面量、变量、赋值、属性/索引访问、一元/二元/逻辑运算、函数调用、lambda 和对象/数组字面量。`Stmt`（语句）涵盖 let、表达式语句、块、if/while/for、函数、return/break/continue |
-| `interpreter/` | 树遍历求值器。`Env` 是基于 `Rc<RefCell<>>` 的链式作用域。`Signal` 枚举通过调用栈传播 `Return`/`Break`/`Continue`。`builtins/` 按 `io` 和 `os` 模块组织原生函数，同时注册为全局函数以方便使用 |
+| `runtime/` | 运行时类型：`Value` 枚举、`FunctionProto`（编译后的函数蓝图）、`Closure`（函数原型 + 捕获的 upvalue）、`Runtime` trait、`NativeFn` 类型。`builtins/` 按功能分组注册原生函数 |
+| `vm/` | 字节码 VM。`Compiler` 将 AST 编译为基于栈的字节码（44 条指令），`Vm` 执行字节码。支持闭包 upvalue 捕获、3 层嵌套闭包、`require()` 模块加载 |
 | `error/` | 三种错误：`LexError`（行列号）、`ParseError`（Token）、`RuntimeError`（可选 Token） |
 
 ### 关键设计决策
 
 - **零外部依赖** — 全部基于 Rust 标准库构建
+- **基于栈的字节码 VM** — AST 先编译为字节码再执行，单一执行路径，无语义漂移
 - **错误容忍解析** — 词法分析器和解析器均将错误收集到 `Vec` 中，单次运行可报告多个诊断信息，而非在第一个错误处就中止
-- **`Rc<RefCell<>>` 共享所有权** — 用于 `Env` 链、`Value::Object`、`Value::Array` 和 `Value::Function`，提供动态可变语义
-- **词法作用域闭包** — `Function` 在定义时捕获 `Env`，lambda 表达式同理
+- **`Rc<RefCell<>>` 共享所有权** — 用于 `Value::Object`、`Value::Array` 和 `UpvalueObj`，提供动态可变语义。闭包通过 upvalue 机制捕获外层局部变量
+- **词法作用域闭包** — 编译时解析 upvalue 捕获，通过增量链路支持任意深度嵌套；`resolve_upvalue` 中显式处理 3 层穿透（本地→父级→祖级），更深层级通过逐层编译自然建立
 
 ## 许可证
 

aster-core/src/analysis.rs

@@ -102,6 +102,19 @@ fn collect_stmt(stmt: &Stmt, symbols: &mut Vec<Symbol>) {
             collect_expr(expr, symbols);
         }
         Stmt::Return(None) | Stmt::Break | Stmt::Continue => {}
+        Stmt::Try { body, catch_var, catch_body, finally_body } => {
+            collect_stmts(body, symbols);
+            if let Some(var) = catch_var {
+                symbols.push(Symbol { name: var.clone(), kind: SymbolKind::Variable });
+            }
+            if let Some(cb) = catch_body {
+                collect_stmts(cb, symbols);
+            }
+            if let Some(fb) = finally_body {
+                collect_stmts(fb, symbols);
+            }
+        }
+        Stmt::Throw(expr) => collect_expr(expr, symbols),
     }
 }
 

aster-core/src/ast/stmt.rs

@@ -58,4 +58,15 @@ pub enum Stmt {
 
     /// continue
     Continue,
+
+    /// try { body } catch (e) { catch_body } finally { finally_body }
+    Try {
+        body: Vec<Stmt>,
+        catch_var: Option<String>,
+        catch_body: Option<Vec<Stmt>>,
+        finally_body: Option<Vec<Stmt>>,
+    },
+
+    /// throw expr;
+    Throw(Expr),
 }

aster-core/src/interpreter/builtins/mod.rs

@@ -1,52 +0,0 @@
-//! 内置函数模块：按功能分组注册，便于扩展和维护。
-
-pub mod core;
-pub mod io;
-pub mod os;
-pub mod string;
-
-use crate::interpreter::{Env, Value};
-use std::cell::RefCell;
-use std::collections::HashMap;
-use std::rc::Rc;
-
-/// 向全局环境注册所有标准库（io、os 等）
-pub fn register_all(env: &Rc<RefCell<Env>>) {
-    let mut e = env.borrow_mut();
-
-    // io
-    let mut io = HashMap::new();
-    io.insert("print".into(), Value::NativeFunction(Rc::new(io::print)));
-    io.insert("input".into(), Value::NativeFunction(Rc::new(io::input)));
-    e.define("io".into(), Value::Object(Rc::new(RefCell::new(io))), true);
-    // input and print can be used as global functions for convenience
-    e.define("print".into(), Value::NativeFunction(Rc::new(io::print)), true);
-    e.define("input".into(), Value::NativeFunction(Rc::new(io::input)), true);
-
-    // os
-    let mut os = HashMap::new();
-    os.insert("clock".into(), Value::NativeFunction(Rc::new(os::clock)));
-    e.define("os".into(), Value::Object(Rc::new(RefCell::new(os))), true);
-    // clock can also be used as a global function for convenience
-    e.define("clock".into(), Value::NativeFunction(Rc::new(os::clock)), true);
-
-    // core — len, typeof, push, pop
-    e.define("len".into(), Value::NativeFunction(Rc::new(core::len)), true);
-    e.define("typeof".into(), Value::NativeFunction(Rc::new(core::typeof_fn)), true);
-    e.define("push".into(), Value::NativeFunction(Rc::new(core::push)), true);
-    e.define("pop".into(), Value::NativeFunction(Rc::new(core::pop)), true);
-
-    // require — module loader
-    e.define("require".into(), Value::NativeFunction(Rc::new(super::module::require_fn)), true);
-
-    // string — split, trim, substring, replace, contains, upper, lower, starts_with, ends_with
-    e.define("split".into(), Value::NativeFunction(Rc::new(string::split)), true);
-    e.define("trim".into(), Value::NativeFunction(Rc::new(string::trim)), true);
-    e.define("substring".into(), Value::NativeFunction(Rc::new(string::substring)), true);
-    e.define("replace".into(), Value::NativeFunction(Rc::new(string::replace)), true);
-    e.define("contains".into(), Value::NativeFunction(Rc::new(string::contains)), true);
-    e.define("upper".into(), Value::NativeFunction(Rc::new(string::upper)), true);
-    e.define("lower".into(), Value::NativeFunction(Rc::new(string::lower)), true);
-    e.define("starts_with".into(), Value::NativeFunction(Rc::new(string::starts_with)), true);
-    e.define("ends_with".into(), Value::NativeFunction(Rc::new(string::ends_with)), true);
-}

aster-core/src/interpreter/env.rs

@@ -1,50 +0,0 @@
-use super::Value;
-use std::collections::HashMap;
-use std::rc::Rc;
-use std::cell::RefCell;
-
-#[derive(Debug)]
-pub struct Env {
-    /// (value, is_mutable) — `is_mutable` is true for `let`, false for `const`.
-    pub values: HashMap<String, (Value, bool)>,
-    pub parent: Option<Rc<RefCell<Env>>>,
-}
-
-impl Env {
-    pub fn new(parent: Option<Rc<RefCell<Env>>>) -> Self {
-        Self {
-            values: HashMap::new(),
-            parent,
-        }
-    }
-
-    pub fn define(&mut self, name: String, val: Value, mutable: bool) {
-        self.values.insert(name, (val, mutable));
-    }
-
-    /// Assign a new value to an existing binding. Returns `Err(msg)` if the
-    /// binding exists but was declared with `const` (immutable).
-    pub fn assign(&mut self, name: &str, val: Value) -> Result<bool, String> {
-        if let Some((_, false)) = self.values.get(name) {
-            return Err(format!("Cannot reassign constant '{}'", name));
-        }
-        if self.values.contains_key(name) {
-            self.values.insert(name.to_string(), (val, true));
-            Ok(true)
-        } else if let Some(parent) = &self.parent {
-            parent.borrow_mut().assign(name, val)
-        } else {
-            Ok(false)
-        }
-    }
-
-    pub fn get(&self, name: &str) -> Option<Value> {
-        if let Some((val, _)) = self.values.get(name) {
-            Some(val.clone())
-        } else if let Some(parent) = &self.parent {
-            parent.borrow().get(name)
-        } else {
-            None
-        }
-    }
-}

aster-core/src/interpreter/eval.rs

@@ -1,624 +0,0 @@
-use crate::ast::*;
-use crate::ast::expr::{Literal, UnaryOp, BinaryOp, LogicalOp, AssignOp};
-use crate::error::RuntimeError;
-use crate::interpreter::Signal;
-use super::{Value, Env, Function};
-use std::collections::HashMap;
-use std::rc::Rc;
-use std::cell::RefCell;
-
-impl super::Interpreter {
-    // ========================================================================
-    // evaluate — dispatcher
-    // ========================================================================
-
-    pub fn evaluate(&mut self, expr: Expr) -> Result<Value, RuntimeError> {
-        match expr {
-            Expr::Literal(lit) => self.eval_literal(lit),
-            Expr::Variable(name) => self.eval_variable(name),
-            Expr::Assign { name, op, value } => self.eval_assign(name, op, *value),
-            Expr::Get { object, name } => self.eval_get(*object, name),
-            Expr::Set { object, name, op, value } => self.eval_set(*object, name, op, *value),
-            Expr::IndexGet { array, index } => self.eval_index_get(*array, *index),
-            Expr::IndexSet { array, index, op, value } => self.eval_index_set(*array, *index, op, *value),
-            Expr::ObjectLiteral { properties } => self.eval_object_literal(properties),
-            Expr::ArrayLiteral { elements } => self.eval_array_literal(elements),
-            Expr::Unary { op, right } => self.eval_unary(op, *right),
-            Expr::Binary { left, op, right } => self.eval_binary(*left, op, *right),
-            Expr::Logical { left, op, right } => self.eval_logical(*left, op, *right),
-            Expr::Ternary { condition, then_branch, else_branch } => {
-                self.eval_ternary(*condition, *then_branch, *else_branch)
-            }
-            Expr::Call { callee, arguments } => self.eval_call(*callee, arguments),
-            Expr::Lambda { params, body } => self.eval_lambda(params, body),
-        }
-    }
-
-    // ========================================================================
-    // eval_* methods
-    // ========================================================================
-
-    fn eval_literal(&mut self, lit: Literal) -> Result<Value, RuntimeError> {
-        Ok(match lit {
-            Literal::Number(n) => Value::Number(n),
-            Literal::String(s) => Value::String(s),
-            Literal::Bool(b) => Value::Bool(b),
-            Literal::Nil => Value::Nil,
-        })
-    }
-
-    fn eval_variable(&mut self, name: String) -> Result<Value, RuntimeError> {
-        match self.env.borrow().get(&name) {
-            Some(val) => Ok(val),
-            None => Err(RuntimeError::RuntimeError {
-                message: format!("Undefined variable '{}'", name),
-                token: None,
-            }),
-        }
-    }
-
-    fn eval_assign(&mut self, name: String, op: AssignOp, value: Expr) -> Result<Value, RuntimeError> {
-        let rhs = self.evaluate(value)?;
-        let val = match op {
-            AssignOp::Equal => rhs,
-            _ => {
-                let current = self.env.borrow().get(&name).ok_or_else(|| RuntimeError::RuntimeError {
-                    message: format!("Undefined variable '{}'", name),
-                    token: None,
-                })?;
-                self.apply_assign_op(current.clone(), rhs, op)?
-            }
-        };
-        match self.env.borrow_mut().assign(&name, val.clone()) {
-            Ok(true) => {}
-            Ok(false) => {
-                return Err(RuntimeError::RuntimeError {
-                    message: format!("Undefined variable '{}'", name),
-                    token: None,
-                });
-            }
-            Err(msg) => {
-                return Err(RuntimeError::RuntimeError {
-                    message: msg,
-                    token: None,
-                });
-            }
-        }
-        Ok(val)
-    }
-
-    fn eval_get(&mut self, object: Expr, name: String) -> Result<Value, RuntimeError> {
-        let obj = self.evaluate(object)?;
-        match obj {
-            Value::Object(_) => {
-                match obj.get(&name) {
-                    Some(val) => Ok(val),
-                    None => Err(RuntimeError::RuntimeError {
-                        message: format!("Undefined property '{}'", name),
-                        token: None,
-                    }),
-                }
-            }
-            Value::Array(arr) => match name.as_str() {
-                "length" => Ok(Value::Number(arr.borrow().len() as f64)),
-                "push" => {
-                    let arr = Rc::clone(&arr);
-                    Ok(Value::NativeFunction(Rc::new(move |_runtime: &mut dyn super::Runtime, mut args: Vec<Value>| {
-                        let val = args.pop().unwrap_or(Value::Nil);
-                        arr.borrow_mut().push(val.clone());
-                        Ok(val)
-                    })))
-                }
-                "pop" => {
-                    let arr = Rc::clone(&arr);
-                    Ok(Value::NativeFunction(Rc::new(move |_runtime: &mut dyn super::Runtime, _args: Vec<Value>| {
-                        arr.borrow_mut()
-                            .pop()
-                            .ok_or_else(|| RuntimeError::RuntimeError {
-                                message: "pop() on empty array".into(),
-                                token: None,
-                            })
-                    })))
-                }
-                _ => Err(RuntimeError::RuntimeError {
-                    message: format!("Array has no property '{}'", name),
-                    token: None,
-                }),
-            },
-            Value::String(s) => match name.as_str() {
-                "length" => Ok(Value::Number(s.chars().count() as f64)),
-                "upper" => {
-                    let s = s.clone();
-                    Ok(Value::NativeFunction(Rc::new(move |runtime: &mut dyn super::Runtime, args: Vec<Value>| {
-                        let mut all_args = vec![Value::String(s.clone())];
-                        all_args.extend(args);
-                        super::builtins::string::upper(runtime, all_args)
-                    })))
-                }
-                "lower" => {
-                    let s = s.clone();
-                    Ok(Value::NativeFunction(Rc::new(move |runtime: &mut dyn super::Runtime, args: Vec<Value>| {
-                        let mut all_args = vec![Value::String(s.clone())];
-                        all_args.extend(args);
-                        super::builtins::string::lower(runtime, all_args)
-                    })))
-                }
-                "trim" => {
-                    let s = s.clone();
-                    Ok(Value::NativeFunction(Rc::new(move |runtime: &mut dyn super::Runtime, args: Vec<Value>| {
-                        let mut all_args = vec![Value::String(s.clone())];
-                        all_args.extend(args);
-                        super::builtins::string::trim(runtime, all_args)
-                    })))
-                }
-                "substring" => {
-                    let s = s.clone();
-                    Ok(Value::NativeFunction(Rc::new(move |runtime: &mut dyn super::Runtime, args: Vec<Value>| {
-                        let mut all_args = vec![Value::String(s.clone())];
-                        all_args.extend(args);
-                        super::builtins::string::substring(runtime, all_args)
-                    })))
-                }
-                "replace" => {
-                    let s = s.clone();
-                    Ok(Value::NativeFunction(Rc::new(move |runtime: &mut dyn super::Runtime, args: Vec<Value>| {
-                        let mut all_args = vec![Value::String(s.clone())];
-                        all_args.extend(args);
-                        super::builtins::string::replace(runtime, all_args)
-                    })))
-                }
-                "contains" => {
-                    let s = s.clone();
-                    Ok(Value::NativeFunction(Rc::new(move |runtime: &mut dyn super::Runtime, args: Vec<Value>| {
-                        let mut all_args = vec![Value::String(s.clone())];
-                        all_args.extend(args);
-                        super::builtins::string::contains(runtime, all_args)
-                    })))
-                }
-                "starts_with" => {
-                    let s = s.clone();
-                    Ok(Value::NativeFunction(Rc::new(move |runtime: &mut dyn super::Runtime, args: Vec<Value>| {
-                        let mut all_args = vec![Value::String(s.clone())];
-                        all_args.extend(args);
-                        super::builtins::string::starts_with(runtime, all_args)
-                    })))
-                }
-                "ends_with" => {
-                    let s = s.clone();
-                    Ok(Value::NativeFunction(Rc::new(move |runtime: &mut dyn super::Runtime, args: Vec<Value>| {
-                        let mut all_args = vec![Value::String(s.clone())];
-                        all_args.extend(args);
-                        super::builtins::string::ends_with(runtime, all_args)
-                    })))
-                }
-                "split" => {
-                    let s = s.clone();
-                    Ok(Value::NativeFunction(Rc::new(move |runtime: &mut dyn super::Runtime, args: Vec<Value>| {
-                        let mut all_args = vec![Value::String(s.clone())];
-                        all_args.extend(args);
-                        super::builtins::string::split(runtime, all_args)
-                    })))
-                }
-                _ => Err(RuntimeError::RuntimeError {
-                    message: format!("String has no property '{}'", name),
-                    token: None,
-                }),
-            },
-            _ => Err(RuntimeError::RuntimeError {
-                message: "Only objects have properties".to_string(),
-                token: None,
-            }),
-        }
-    }
-
-    fn eval_set(&mut self, object: Expr, name: String, op: AssignOp, value: Expr) -> Result<Value, RuntimeError> {
-        let obj = self.evaluate(object)?;
-        let rhs = self.evaluate(value)?;
-        match obj {
-            Value::Object(_) => {
-                let val = match op {
-                    AssignOp::Equal => rhs,
-                    _ => {
-                        let current = obj.get(&name).ok_or_else(|| RuntimeError::RuntimeError {
-                            message: format!("Property '{}' does not exist", name),
-                            token: None,
-                        })?;
-                        self.apply_assign_op(current, rhs, op)?
-                    }
-                };
-                obj.set(&name, val.clone())?;
-                Ok(val)
-            }
-            _ => Err(RuntimeError::RuntimeError {
-                message: "Only objects have properties".to_string(),
-                token: None,
-            }),
-        }
-    }
-
-    fn eval_index_get(&mut self, array: Expr, index: Expr) -> Result<Value, RuntimeError> {
-        let target = self.evaluate(array)?;
-        let idx_val = self.evaluate(index)?;
-        // Object index access: obj["key"]
-        if let Value::Object(_) = &target {
-            let key = match &idx_val {
-                Value::String(s) => s.clone(),
-                _ => return Err(RuntimeError::RuntimeError {
-                    message: "Object index must be a string".into(),
-                    token: None,
-                }),
-            };
-            return target.get(&key).ok_or_else(|| RuntimeError::RuntimeError {
-                message: format!("Undefined property '{}'", key),
-                token: None,
-            });
-        }
-        let i = self.as_array_index(&idx_val)?;
-        match target {
-            Value::Array(vec) => {
-                let vec = vec.borrow();
-                vec.get(i).cloned().ok_or_else(|| RuntimeError::RuntimeError {
-                    message: format!("Index {} out of bounds (len {})", i, vec.len()),
-                    token: None,
-                })
-            }
-            Value::String(s) => {
-                let chars: Vec<char> = s.chars().collect();
-                chars.get(i).map(|&c| Value::String(c.to_string())).ok_or_else(|| RuntimeError::RuntimeError {
-                    message: format!("Index {} out of bounds (len {})", i, chars.len()),
-                    token: None,
-                })
-            }
-            _ => Err(RuntimeError::RuntimeError {
-                message: "Index access on non-array, non-string, non-object value".to_string(),
-                token: None,
-            }),
-        }
-    }
-
-    fn eval_index_set(&mut self, array: Expr, index: Expr, op: AssignOp, value: Expr) -> Result<Value, RuntimeError> {
-        let target = self.evaluate(array)?;
-        let idx_val = self.evaluate(index)?;
-        let rhs = self.evaluate(value)?;
-        // Object index assignment: obj["key"] = value
-        if let Value::Object(_) = &target {
-            let key = match &idx_val {
-                Value::String(s) => s.clone(),
-                _ => return Err(RuntimeError::RuntimeError {
-                    message: "Object index must be a string".into(),
-                    token: None,
-                }),
-            };
-            let val = match op {
-                AssignOp::Equal => rhs,
-                _ => {
-                    let current = target.get(&key).ok_or_else(|| RuntimeError::RuntimeError {
-                        message: format!("Property '{}' does not exist", key),
-                        token: None,
-                    })?;
-                    self.apply_assign_op(current, rhs, op)?
-                }
-            };
-            target.set(&key, val.clone())?;
-            return Ok(val);
-        }
-        let i = self.as_array_index(&idx_val)?;
-        match target {
-            Value::Array(vec) => {
-                let mut vec = vec.borrow_mut();
-                if i >= vec.len() {
-                    return Err(RuntimeError::RuntimeError {
-                        message: format!("Index {} out of bounds (len {})", i, vec.len()),
-                        token: None,
-                    });
-                }
-                let val = match op {
-                    AssignOp::Equal => rhs,
-                    _ => {
-                        let current = vec[i].clone();
-                        self.apply_assign_op(current, rhs, op)?
-                    }
-                };
-                vec[i] = val.clone();
-                Ok(val)
-            }
-            _ => Err(RuntimeError::RuntimeError {
-                message: "Index assignment on non-array, non-object value".to_string(),
-                token: None,
-            }),
-        }
-    }
-
-    fn eval_object_literal(&mut self, properties: Vec<(String, Expr)>) -> Result<Value, RuntimeError> {
-        let mut map = HashMap::new();
-        for (key, value_expr) in properties {
-            let value = self.evaluate(value_expr)?;
-            map.insert(key, value);
-        }
-        Ok(Value::Object(Rc::new(RefCell::new(map))))
-    }
-
-    fn eval_array_literal(&mut self, elements: Vec<Expr>) -> Result<Value, RuntimeError> {
-        let mut arr = Vec::new();
-        for e in elements {
-            arr.push(self.evaluate(e)?);
-        }
-        Ok(Value::Array(Rc::new(RefCell::new(arr))))
-    }
-
-    fn eval_unary(&mut self, op: UnaryOp, right: Expr) -> Result<Value, RuntimeError> {
-        let val = self.evaluate(right)?;
-        match op {
-            UnaryOp::Negate => match val {
-                Value::Number(n) => Ok(Value::Number(-n)),
-                _ => Err(RuntimeError::RuntimeError {
-                    message: "Unary '-' on non-number".to_string(),
-                    token: None,
-                }),
-            },
-            UnaryOp::Not => Ok(Value::Bool(!self.is_truthy(&val))),
-        }
-    }
-
-    fn eval_binary(&mut self, left: Expr, op: BinaryOp, right: Expr) -> Result<Value, RuntimeError> {
-        let l = self.evaluate(left)?;
-        let r = self.evaluate(right)?;
-        match op {
-            BinaryOp::Add => self.eval_binary_add(l, r),
-            BinaryOp::Sub => self.eval_binary_arith(l, r, |a, b| a - b, "-"),
-            BinaryOp::Mul => self.eval_binary_arith(l, r, |a, b| a * b, "*"),
-            BinaryOp::Div => self.eval_binary_div(l, r),
-            BinaryOp::Mod => self.eval_binary_mod(l, r),
-            BinaryOp::Greater => Ok(Value::Bool(self.as_number(&l)? > self.as_number(&r)?)),
-            BinaryOp::GreaterEqual => Ok(Value::Bool(self.as_number(&l)? >= self.as_number(&r)?)),
-            BinaryOp::Less => Ok(Value::Bool(self.as_number(&l)? < self.as_number(&r)?)),
-            BinaryOp::LessEqual => Ok(Value::Bool(self.as_number(&l)? <= self.as_number(&r)?)),
-            BinaryOp::Equal => Ok(Value::Bool(self.is_equal(&l, &r))),
-            BinaryOp::NotEqual => Ok(Value::Bool(!self.is_equal(&l, &r))),
-        }
-    }
-
-    fn eval_binary_add(&mut self, l: Value, r: Value) -> Result<Value, RuntimeError> {
-        if matches!(l, Value::String(_)) || matches!(r, Value::String(_)) {
-            Ok(Value::String(format!("{}{}", l, r)))
-        } else {
-            match (l, r) {
-                (Value::Number(a), Value::Number(b)) => Ok(Value::Number(a + b)),
-                _ => Err(RuntimeError::RuntimeError {
-                    message: "Invalid '+' operands".to_string(),
-                    token: None,
-                }),
-            }
-        }
-    }
-
-    fn eval_binary_arith(
-        &mut self,
-        l: Value,
-        r: Value,
-        op_fn: fn(f64, f64) -> f64,
-        name: &str,
-    ) -> Result<Value, RuntimeError> {
-        match (l, r) {
-            (Value::Number(a), Value::Number(b)) => Ok(Value::Number(op_fn(a, b))),
-            _ => Err(RuntimeError::RuntimeError {
-                message: format!("Invalid '{}' operands", name),
-                token: None,
-            }),
-        }
-    }
-
-    fn eval_binary_div(&mut self, l: Value, r: Value) -> Result<Value, RuntimeError> {
-        match (l, r) {
-            (Value::Number(_), Value::Number(b)) if b == 0.0 => Err(RuntimeError::RuntimeError {
-                message: "Division by zero".to_string(),
-                token: None,
-            }),
-            (Value::Number(a), Value::Number(b)) => Ok(Value::Number(a / b)),
-            _ => Err(RuntimeError::RuntimeError {
-                message: "Invalid '/' operands".to_string(),
-                token: None,
-            }),
-        }
-    }
-
-    fn eval_binary_mod(&mut self, l: Value, r: Value) -> Result<Value, RuntimeError> {
-        match (l, r) {
-            (Value::Number(_), Value::Number(b)) if b == 0.0 => Err(RuntimeError::RuntimeError {
-                message: "Modulo by zero".to_string(),
-                token: None,
-            }),
-            (Value::Number(a), Value::Number(b)) => Ok(Value::Number(a % b)),
-            _ => Err(RuntimeError::RuntimeError {
-                message: "Invalid '%' operands".to_string(),
-                token: None,
-            }),
-        }
-    }
-
-    fn eval_logical(&mut self, left: Expr, op: LogicalOp, right: Expr) -> Result<Value, RuntimeError> {
-        let l = self.evaluate(left)?;
-        match op {
-            LogicalOp::And => {
-                Ok(if !self.is_truthy(&l) { l } else { self.evaluate(right)? })
-            }
-            LogicalOp::Or => {
-                Ok(if self.is_truthy(&l) { l } else { self.evaluate(right)? })
-            }
-        }
-    }
-
-    fn eval_ternary(&mut self, condition: Expr, then_branch: Expr, else_branch: Expr) -> Result<Value, RuntimeError> {
-        let cond = self.evaluate(condition)?;
-        if self.is_truthy(&cond) {
-            self.evaluate(then_branch)
-        } else {
-            self.evaluate(else_branch)
-        }
-    }
-
-    fn eval_call(&mut self, callee: Expr, arguments: Vec<Expr>) -> Result<Value, RuntimeError> {
-        let func = self.evaluate(callee)?;
-        let mut args = Vec::new();
-        for e in arguments {
-            args.push(self.evaluate(e)?);
-        }
-        self.call_function(func, args)
-    }
-
-    fn eval_lambda(&mut self, params: Vec<String>, body: Vec<Stmt>) -> Result<Value, RuntimeError> {
-        Ok(Value::Function(Rc::new(Function {
-            params,
-            body,
-            env: Rc::clone(&self.env),
-            name: None,
-        })))
-    }
-
-    // ========================================================================
-    // call_function
-    // ========================================================================
-
-    pub fn call_function(&mut self, func_val: Value, args: Vec<Value>) -> Result<Value, RuntimeError> {
-        match func_val {
-            Value::NativeFunction(native_fn) => native_fn(self as &mut dyn super::Runtime, args),
-            Value::Function(f) => self.call_user_function(f, args),
-            _ => Err(RuntimeError::RuntimeError {
-                message: "Attempt to call non-function".to_string(),
-                token: None,
-            }),
-        }
-    }
-
-    fn call_user_function(&mut self, f: Rc<Function>, args: Vec<Value>) -> Result<Value, RuntimeError> {
-        let env = Rc::new(RefCell::new(Env::new(Some(Rc::clone(&f.env)))));
-
-        if let Some(name) = &f.name {
-            env.borrow_mut().define(name.clone(), Value::Function(Rc::clone(&f)), true);
-        }
-
-        for (i, param) in f.params.iter().enumerate() {
-            let val = args.get(i).cloned().unwrap_or(Value::Nil);
-            env.borrow_mut().define(param.clone(), val, true);
-        }
-
-        let previous = Rc::clone(&self.env);
-        self.env = env;
-        let mut ret = Value::Nil;
-        for stmt in &f.body {
-            match self.execute(stmt.clone())? {
-                Signal::Return(val) => { ret = val; break; }
-                Signal::None => {}
-                Signal::Break | Signal::Continue => {
-                    return Err(RuntimeError::RuntimeError {
-                        message: "break/continue outside of loop".to_string(),
-                        token: None,
-                    });
-                }
-            }
-        }
-        self.env = previous;
-        Ok(ret)
-    }
-
-    // ========================================================================
-    // Helpers
-    // ========================================================================
-
-    pub fn is_truthy(&self, val: &Value) -> bool {
-        match val {
-            Value::Nil => false,
-            Value::Bool(b) => *b,
-            _ => true,
-        }
-    }
-
-    pub fn is_equal(&self, a: &Value, b: &Value) -> bool {
-        match (a, b) {
-            (Value::Nil, Value::Nil) => true,
-            (Value::Bool(x), Value::Bool(y)) => x == y,
-            (Value::Number(x), Value::Number(y)) => x == y,
-            (Value::String(x), Value::String(y)) => x == y,
-            (Value::Array(x), Value::Array(y)) => {
-                let x = x.borrow();
-                let y = y.borrow();
-                if x.len() != y.len() { return false; }
-                x.iter().zip(y.iter()).all(|(a, b)| self.is_equal(a, b))
-            }
-            (Value::Object(x), Value::Object(y)) => {
-                let x = x.borrow();
-                let y = y.borrow();
-                if x.len() != y.len() { return false; }
-                x.iter().all(|(k, v)| {
-                    y.get(k).map_or(false, |yv| self.is_equal(v, yv))
-                })
-            }
-            (Value::Function(x), Value::Function(y)) => Rc::ptr_eq(x, y),
-            (Value::NativeFunction(x), Value::NativeFunction(y)) => Rc::ptr_eq(x, y),
-            _ => false,
-        }
-    }
-
-    pub fn apply_assign_op(&self, left: Value, right: Value, op: AssignOp) -> Result<Value, RuntimeError> {
-        match op {
-            AssignOp::Equal => Ok(right),
-            AssignOp::PlusEqual => {
-                if let Value::String(s) = &left {
-                    Ok(Value::String(format!("{}{}", s, right)))
-                } else {
-                    let left_num = self.as_number(&left)?;
-                    let right_num = self.as_number(&right)?;
-                    Ok(Value::Number(left_num + right_num))
-                }
-            }
-            AssignOp::MinusEqual => {
-                let left_num = self.as_number(&left)?;
-                let right_num = self.as_number(&right)?;
-                Ok(Value::Number(left_num - right_num))
-            }
-            AssignOp::StarEqual => {
-                let left_num = self.as_number(&left)?;
-                let right_num = self.as_number(&right)?;
-                Ok(Value::Number(left_num * right_num))
-            }
-            AssignOp::SlashEqual => {
-                let left_num = self.as_number(&left)?;
-                let right_num = self.as_number(&right)?;
-                Ok(Value::Number(left_num / right_num))
-            }
-            AssignOp::PercentEqual => {
-                let left_num = self.as_number(&left)?;
-                let right_num = self.as_number(&right)?;
-                Ok(Value::Number(left_num % right_num))
-            }
-        }
-    }
-
-    pub fn as_number(&self, val: &Value) -> Result<f64, RuntimeError> {
-        if let Value::Number(n) = val {
-            Ok(*n)
-        } else {
-            Err(RuntimeError::RuntimeError {
-                message: "Expected number".to_string(),
-                token: None,
-            })
-        }
-    }
-
-    pub fn as_array_index(&self, val: &Value) -> Result<usize, RuntimeError> {
-        if let Value::Number(n) = val {
-            if *n < 0.0 || n.fract() != 0.0 {
-                return Err(RuntimeError::RuntimeError {
-                    message: format!("Index must be a non-negative integer, got {}", n),
-                    token: None,
-                });
-            }
-            Ok(*n as usize)
-        } else {
-            Err(RuntimeError::RuntimeError {
-                message: "Index must be a number".to_string(),
-                token: None,
-            })
-        }
-    }
-}

aster-core/src/interpreter/exec.rs

@@ -1,192 +0,0 @@
-use crate::ast::*;
-use crate::error::RuntimeError;
-use crate::interpreter::Signal;
-use super::{Value, Env, Function};
-use std::rc::Rc;
-use std::cell::RefCell;
-
-impl super::Interpreter {
-    // ========================================================================
-    // execute — dispatcher
-    // ========================================================================
-
-    pub fn execute(&mut self, stmt: Stmt) -> Result<Signal, RuntimeError> {
-        match stmt {
-            Stmt::Let { name, initializer, mutable } => self.exec_let(name, initializer, mutable),
-            Stmt::ExprStmt(expr) => self.exec_expr_stmt(expr),
-            Stmt::Block(stmts) => self.exec_block(stmts),
-            Stmt::If { condition, then_branch, else_branch } => {
-                self.exec_if(condition, *then_branch, else_branch.map(|b| *b))
-            }
-            Stmt::While { condition, body } => self.exec_while(condition, *body),
-            Stmt::For { initializer, condition, step, body } => {
-                self.exec_for(initializer, condition, step, *body)
-            }
-            Stmt::ForIn { var_name, iterable, body } => self.exec_for_in(var_name, iterable, *body),
-            Stmt::Function { name, params, body } => self.exec_function(name, params, body),
-            Stmt::Return(expr_opt) => self.exec_return(expr_opt),
-            Stmt::Break => Ok(Signal::Break),
-            Stmt::Continue => Ok(Signal::Continue),
-        }
-    }
-
-    // ========================================================================
-    // exec_* methods
-    // ========================================================================
-
-    fn exec_let(&mut self, name: String, initializer: Expr, mutable: bool) -> Result<Signal, RuntimeError> {
-        let val = self.evaluate(initializer)?;
-        self.env.borrow_mut().define(name, val, mutable);
-        Ok(Signal::None)
-    }
-
-    fn exec_expr_stmt(&mut self, expr: Expr) -> Result<Signal, RuntimeError> {
-        self.evaluate(expr)?;
-        Ok(Signal::None)
-    }
-
-    fn exec_block(&mut self, stmts: Vec<Stmt>) -> Result<Signal, RuntimeError> {
-        let previous = Rc::clone(&self.env);
-        self.env = Rc::new(RefCell::new(Env::new(Some(previous))));
-        let mut signal = Signal::None;
-        for s in stmts {
-            signal = self.execute(s)?;
-            if !matches!(signal, Signal::None) {
-                break;
-            }
-        }
-        let parent = self.env.borrow().parent.as_ref().unwrap().clone();
-        self.env = parent;
-        Ok(signal)
-    }
-
-    fn exec_if(
-        &mut self,
-        condition: Expr,
-        then_branch: Stmt,
-        else_branch: Option<Stmt>,
-    ) -> Result<Signal, RuntimeError> {
-        let cond_val = self.evaluate(condition)?;
-        if self.is_truthy(&cond_val) {
-            self.execute(then_branch)
-        } else if let Some(else_branch) = else_branch {
-            self.execute(else_branch)
-        } else {
-            Ok(Signal::None)
-        }
-    }
-
-    fn exec_while(&mut self, condition: Expr, body: Stmt) -> Result<Signal, RuntimeError> {
-        loop {
-            let cond_val = self.evaluate(condition.clone())?;
-            if !self.is_truthy(&cond_val) {
-                break;
-            }
-            match self.execute(body.clone())? {
-                Signal::Break => break,
-                Signal::Continue => continue,
-                sig @ Signal::Return(_) => return Ok(sig),
-                Signal::None => {}
-            }
-        }
-        Ok(Signal::None)
-    }
-
-    fn exec_for(
-        &mut self,
-        initializer: Option<Box<Stmt>>,
-        condition: Option<Expr>,
-        step: Option<Expr>,
-        body: Stmt,
-    ) -> Result<Signal, RuntimeError> {
-        if let Some(init) = initializer {
-            self.execute(*init)?;
-        }
-        loop {
-            if let Some(cond) = &condition {
-                let cond_val = self.evaluate(cond.clone())?;
-                if !self.is_truthy(&cond_val) {
-                    break;
-                }
-            }
-            match self.execute(body.clone())? {
-                Signal::Break => break,
-                Signal::Continue => {
-                    if let Some(step) = &step {
-                        self.evaluate(step.clone())?;
-                    }
-                    continue;
-                }
-                sig @ Signal::Return(_) => return Ok(sig),
-                Signal::None => {}
-            }
-            if let Some(step) = &step {
-                self.evaluate(step.clone())?;
-            }
-        }
-        Ok(Signal::None)
-    }
-
-    fn exec_for_in(
-        &mut self,
-        var_name: String,
-        iterable: Expr,
-        body: Stmt,
-    ) -> Result<Signal, RuntimeError> {
-        let iter_val = self.evaluate(iterable)?;
-        let items: Vec<Value> = match &iter_val {
-            Value::Array(arr) => arr.borrow().clone(),
-            Value::Object(obj) => obj.borrow().keys().map(|k| Value::String(k.clone())).collect(),
-            Value::String(s) => s.chars().map(|c| Value::String(c.to_string())).collect(),
-            _ => {
-                return Err(RuntimeError::RuntimeError {
-                    message: "for-in requires an array, object, or string".into(),
-                    token: None,
-                });
-            }
-        };
-
-        let mut signal = Signal::None;
-        for item in items {
-            let previous = Rc::clone(&self.env);
-            self.env = Rc::new(RefCell::new(Env::new(Some(previous))));
-            self.env.borrow_mut().define(var_name.clone(), item, true);
-
-            signal = self.execute(body.clone())?;
-            let parent = self.env.borrow().parent.as_ref().unwrap().clone();
-            self.env = parent;
-
-            match signal {
-                Signal::Break => { signal = Signal::None; break; }
-                Signal::Continue => { signal = Signal::None; continue; }
-                sig @ Signal::Return(_) => return Ok(sig),
-                Signal::None => {}
-            }
-        }
-        Ok(signal)
-    }
-
-    fn exec_function(
-        &mut self,
-        name: String,
-        params: Vec<String>,
-        body: Vec<Stmt>,
-    ) -> Result<Signal, RuntimeError> {
-        let func = Value::Function(Rc::new(Function {
-            params,
-            body,
-            env: Rc::clone(&self.env),
-            name: Some(name.clone()),
-        }));
-        self.env.borrow_mut().define(name, func, true);
-        Ok(Signal::None)
-    }
-
-    fn exec_return(&mut self, expr_opt: Option<Expr>) -> Result<Signal, RuntimeError> {
-        if let Some(expr) = expr_opt {
-            Ok(Signal::Return(self.evaluate(expr)?))
-        } else {
-            Ok(Signal::Return(Value::Nil))
-        }
-    }
-}

aster-core/src/interpreter/interpreter.rs

@@ -1,55 +0,0 @@
-use crate::ast::*;
-use crate::error::RuntimeError;
-use super::{Env, Value};
-use std::collections::HashMap;
-use std::rc::Rc;
-use std::cell::RefCell;
-
-pub struct Interpreter {
-    /// 当前作用域（用户代码所在 env，parent 指向 builtins_env）
-    pub env: Rc<RefCell<Env>>,
-    /// 内置函数根作用域（parent = None，所有内置函数注册在此）
-    pub builtins_env: Rc<RefCell<Env>>,
-    /// 模块缓存：规范路径 → exports 对象
-    pub module_cache: RefCell<HashMap<String, Value>>,
-    /// 当前执行文件的目录，用于 require() 解析相对路径
-    pub current_dir: String,
-}
-
-impl Interpreter {
-    pub fn new() -> Self {
-        // 根层：仅包含内置函数
-        let builtins_env = Rc::new(RefCell::new(Env::new(None)));
-        super::builtins::register_all(&builtins_env);
-
-        // 用户层：parent 指向 builtins_env，用户定义的变量都在这层
-        let script_env = Rc::new(RefCell::new(Env::new(Some(Rc::clone(&builtins_env)))));
-
-        Self {
-            env: script_env,
-            builtins_env,
-            module_cache: RefCell::new(HashMap::new()),
-            current_dir: std::env::current_dir()
-                .map(|p| p.to_string_lossy().to_string())
-                .unwrap_or_else(|_| ".".to_string()),
-        }
-    }
-
-    /// 指定当前目录的构造器，用于 `run_file` 时设置脚本所在目录
-    pub fn with_current_dir(dir: String) -> Self {
-        let mut interp = Self::new();
-        interp.current_dir = dir;
-        interp
-    }
-
-    pub fn interpret(&mut self, statements: Vec<Stmt>) -> Result<(), RuntimeError> {
-        for stmt in statements {
-            self.execute(stmt)?;
-        }
-        Ok(())
-    }
-}
-
-#[cfg(test)]
-#[path = "tests.rs"]
-mod tests;

aster-core/src/interpreter/mod.rs

@@ -1,133 +1,3 @@
-pub mod builtins;
-pub mod env;
-pub mod eval;
-pub mod exec;
-pub mod interpreter;
-pub mod module;
-
-pub use env::Env;
-pub use interpreter::Interpreter;
-
-use std::collections::HashMap;
-use std::rc::Rc;
-use std::cell::RefCell;
-use std::fmt;
-
-/// Trait abstracting runtime services that native functions may need.
-/// Both the tree-walking `Interpreter` and the bytecode `Vm` implement this.
-pub trait Runtime {
-    /// Load and execute a module, returning its exports object.
-    /// Implementations differ: tree-walker interprets directly,
-    /// VM compiles to bytecode then executes.
-    fn require(&mut self, path: &str) -> Result<Value, crate::error::RuntimeError>;
-}
-
-pub type NativeFn = Rc<dyn Fn(&mut dyn Runtime, Vec<Value>) -> Result<Value, crate::error::RuntimeError>>;
-
-#[derive(Clone)]
-pub enum Value {
-    Number(f64),
-    String(String),
-    Bool(bool),
-    Nil,
-    Object(Rc<RefCell<HashMap<String, Value>>>),
-    Array(Rc<RefCell<Vec<Value>>>),
-    Function(Rc<Function>),
-    NativeFunction(NativeFn),
-}
-
-pub enum Signal {
-    None,           // 正常执行
-    Return(Value),  // return 语句携带的返回值
-    Break,          // break 信号
-    Continue,       // continue 信号
-}
-
-impl Value {
-    pub fn get(&self, key: &str) -> Option<Value> {
-        match self {
-            Value::Object(obj) => obj.borrow().get(key).cloned(),
-            _ => None,
-        }
-    }
-
-    pub fn set(&self, key: &str, val: Value) -> Result<(), crate::error::RuntimeError> {
-        match self {
-            Value::Object(obj) => {
-                obj.borrow_mut().insert(key.to_string(), val);
-                Ok(())
-            },
-            _ => Err(crate::error::RuntimeError::RuntimeError {
-                message: "Only objects have properties".to_string(),
-                token: None,
-            }),
-        }
-    }
-}
-
-impl std::fmt::Debug for Value {
-    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
-        match self {
-            Value::Number(n) => write!(f, "Number({:?})", n),
-            Value::String(s) => write!(f, "String({:?})", s),
-            Value::Bool(b) => write!(f, "Bool({:?})", b),
-            Value::Nil => write!(f, "Nil"),
-            Value::Object(_) => write!(f, "Object(...)"),
-            Value::Array(_) => write!(f, "Array(...)"),
-            Value::Function(_) => write!(f, "Function(...)"),
-            Value::NativeFunction(_) => write!(f, "NativeFunction(...)"),
-        }
-    }
-}
-
-impl Value {
-    /// 容器内值的格式化：字符串加引号以区分类型，其余类型用 Display
-    fn fmt_element(&self, f: &mut fmt::Formatter) -> fmt::Result {
-        match self {
-            Value::String(s) => write!(f, "\"{}\"", s),
-            other => write!(f, "{}", other),
-        }
-    }
-}
-
-impl fmt::Display for Value {
-    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
-        match self {
-            Value::Number(n) => write!(f, "{}", n),
-            Value::String(s) => write!(f, "{}", s),
-            Value::Bool(b) => write!(f, "{}", b),
-            Value::Nil => write!(f, "nil"),
-            Value::Object(obj) => {
-                let obj = obj.borrow();
-                write!(f, "{{ ")?;
-                for (key, value) in obj.iter() {
-                    write!(f, "{}: ", key)?;
-                    value.fmt_element(f)?;
-                    write!(f, ", ")?;
-                }
-                write!(f, "}}")
-            },
-            Value::Array(arr) => {
-                let arr = arr.borrow();
-                write!(f, "[")?;
-                for (i, val) in arr.iter().enumerate() {
-                    if i > 0 {
-                        write!(f, ", ")?;
-                    }
-                    val.fmt_element(f)?;
-                }
-                write!(f, "]")
-            },
-            Value::Function(_) => write!(f, "<function>"),
-            Value::NativeFunction(_) => write!(f, "<native function>"),
-        }
-    }
-}
-
-#[derive(Debug, Clone)]
-pub struct Function {
-    pub params: Vec<String>,
-    pub body: Vec<crate::ast::Stmt>,
-    pub env: Rc<RefCell<Env>>, // 闭包捕获环境
-    pub name: Option<String>,
-}
+// Re-export shared types from runtime (backward compatibility)
+pub use crate::runtime::{Value, NativeFn, Runtime};
+pub use crate::runtime::builtins;

aster-core/src/interpreter/module.rs

@@ -1,143 +0,0 @@
-//! 模块系统：require() 加载器
-//!
-//! `require("path/to/module.ast")` 加载并执行指定的 Aster 文件，
-//! 返回一个包含模块所有顶层定义的 `Value::Object`。
-//! 模块在自己的作用域中执行，只能访问内置函数，无法访问调用者的变量。
-//! 第二次 require 同一文件会返回缓存的对象。
-
-use crate::error::RuntimeError;
-use crate::lexer::Lexer;
-use crate::parser::Parser;
-use super::{Interpreter, Env, Value, Signal, Runtime};
-use std::cell::RefCell;
-use std::collections::HashMap;
-use std::path::Path;
-use std::rc::Rc;
-
-impl Runtime for Interpreter {
-    fn require(&mut self, path: &str) -> Result<Value, RuntimeError> {
-        require_impl(self, path)
-    }
-}
-
-/// require() 的内置函数实现 — 薄包装，委托给 Runtime::require
-pub fn require_fn(runtime: &mut dyn Runtime, args: Vec<Value>) -> Result<Value, RuntimeError> {
-    let path_str = match args.first() {
-        Some(Value::String(s)) => s.clone(),
-        Some(other) => return Err(runtime_error(format!(
-            "require() expects a string argument, got {}", other))),
-        None => return Err(runtime_error(
-            "require() expects 1 argument (string path)")),
-    };
-    runtime.require(&path_str)
-}
-
-/// require() 的内部实现 (供 Interpreter::require 使用)
-fn require_impl(interp: &mut Interpreter, path_str: &str) -> Result<Value, RuntimeError> {
-    // 1. 路径解析
-    let resolved = resolve_path(&interp.current_dir, path_str)?;
-
-    // 2. 缓存查找
-    if let Some(cached) = interp.module_cache.borrow().get(&resolved) {
-        return Ok(cached.clone());
-    }
-
-    // 3. 读取文件
-    let src = std::fs::read_to_string(&resolved)
-        .map_err(|e| runtime_error(format!(
-            "Module '{}' not found: {}", path_str, e)))?;
-
-    // 4. 词法分析
-    let (tokens, lex_errors) = Lexer::new(&src).tokenize();
-    if !lex_errors.is_empty() {
-        return Err(runtime_error(format!(
-            "Lex error in module '{}': {}", path_str, lex_errors[0])));
-    }
-
-    // 5. 语法分析
-    let mut parser = Parser::new(tokens);
-    let (stmts, parse_errors) = parser.parse();
-    if !parse_errors.is_empty() {
-        return Err(runtime_error(format!(
-            "Parse error in module '{}': {}", path_str, parse_errors[0])));
-    }
-
-    // 6. 创建隔离的模块 env（父级 = builtins_env，看不到调用者的变量）
-    let module_env = Rc::new(RefCell::new(Env::new(Some(Rc::clone(&interp.builtins_env)))));
-
-    // 7. 在缓存中插入占位符（支持循环 require）
-    let exports_map = Rc::new(RefCell::new(HashMap::new()));
-    let exports = Value::Object(Rc::clone(&exports_map));
-    interp.module_cache.borrow_mut().insert(resolved.clone(), exports.clone());
-
-    // 8. 保存调用者状态
-    let previous_env = Rc::clone(&interp.env);
-    let previous_dir = interp.current_dir.clone();
-
-    // 9. 切换到模块上下文
-    interp.env = module_env.clone();
-    interp.current_dir = module_dir(&resolved);
-
-    // 10. 执行模块
-    for stmt in &stmts {
-        match interp.execute(stmt.clone()) {
-            Ok(Signal::Break) | Ok(Signal::Continue) => {
-                interp.env = previous_env;
-                interp.current_dir = previous_dir;
-                interp.module_cache.borrow_mut().remove(&resolved);
-                return Err(runtime_error(
-                    "break/continue outside of loop in module"));
-            }
-            Err(e) => {
-                interp.env = previous_env;
-                interp.current_dir = previous_dir;
-                interp.module_cache.borrow_mut().remove(&resolved);
-                return Err(e);
-            }
-            Ok(Signal::None) | Ok(Signal::Return(_)) => {}
-        }
-    }
-
-    // 11. 恢复调用者状态
-    interp.env = previous_env;
-    interp.current_dir = previous_dir;
-
-    // 12. 收集 exports（模块 env 中的所有直接绑定）
-    for (name, (val, _mutable)) in module_env.borrow().values.clone() {
-        exports_map.borrow_mut().insert(name, val);
-    }
-
-    Ok(exports)
-}
-
-// ============================================================================
-// Helpers
-// ============================================================================
-
-fn resolve_path(current_dir: &str, path_str: &str) -> Result<String, RuntimeError> {
-    let path = Path::new(path_str);
-    let resolved = if path.is_absolute() {
-        path.to_path_buf()
-    } else {
-        Path::new(current_dir).join(path)
-    };
-    std::fs::canonicalize(&resolved)
-        .map(|p| p.to_string_lossy().to_string())
-        .map_err(|_| runtime_error(format!(
-            "Module '{}' not found (resolved to '{}')",
-            path_str, resolved.display())))
-}
-
-fn module_dir(resolved: &str) -> String {
-    Path::new(resolved)
-        .parent()
-        .map(|p| p.to_string_lossy().to_string())
-        .unwrap_or_else(|| ".".to_string())
-}
-
-fn runtime_error(msg: impl Into<String>) -> RuntimeError {
-    RuntimeError::RuntimeError {
-        message: msg.into(),
-        token: None,
-    }
-}

aster-core/src/lexer/lexer.rs

@@ -360,6 +360,10 @@ impl Lexer {
             "true" => TokenKind::True,
             "false" => TokenKind::False,
             "nil" => TokenKind::Nil,
+            "try" => TokenKind::Try,
+            "catch" => TokenKind::Catch,
+            "finally" => TokenKind::Finally,
+            "throw" => TokenKind::Throw,
             _ => TokenKind::Identifier(s),
         };
 

aster-core/src/lexer/token.rs

@@ -39,6 +39,10 @@ pub enum TokenKind {
     True,
     False,
     Nil,
+    Try,
+    Catch,
+    Finally,
+    Throw,
 
     EOF,
 }

aster-core/src/lib.rs

@@ -1,6 +1,7 @@
 pub mod lexer;
 pub mod ast;
 pub mod parser;
+pub mod runtime;
 pub mod interpreter;
 pub mod vm;
 pub mod error;
@@ -8,7 +9,6 @@ pub mod analysis;
 
 use lexer::Lexer;
 use parser::Parser;
-use interpreter::Interpreter;
 use vm::compiler::Compiler;
 use vm::vm::Vm;
 use error::RuntimeError;
@@ -37,33 +37,6 @@ pub fn run_file(filename: &str, src: String) {
         std::process::exit(65);
     }
 
-    let script_dir = std::path::Path::new(filename)
-        .parent()
-        .map(|p| p.to_string_lossy().to_string())
-        .unwrap_or_else(|| ".".to_string());
-
-    let mut interpreter = Interpreter::with_current_dir(script_dir);
-    if let Err(e) = interpreter.interpret(stmts) {
-        eprintln!("Error: {}", e);
-        std::process::exit(70);
-    }
-}
-
-/// Run a file using the bytecode VM (for performance comparison).
-pub fn run_file_vm(filename: &str, src: String) {
-    let (tokens, lex_errors) = Lexer::new(&src).tokenize();
-    if !lex_errors.is_empty() {
-        print_errors(&lex_errors);
-        std::process::exit(65);
-    }
-
-    let mut parser = Parser::new(tokens);
-    let (stmts, parse_errors) = parser.parse();
-    if !parse_errors.is_empty() {
-        print_errors(&parse_errors);
-        std::process::exit(65);
-    }
-
     let script_dir = std::path::Path::new(filename)
         .parent()
         .map(|p| p.to_string_lossy().to_string())
@@ -87,9 +60,9 @@ pub fn run_file_vm(filename: &str, src: String) {
 pub fn run_repl() {
     println!("Welcome to Aster REPL!");
     println!("Type ':exit' to quit.");
-    println!("Type ':reset' to reset the interpreter state.");
+    println!("Type ':reset' to reset the VM state.");
 
-    let mut interpreter = Interpreter::new();
+    let mut vm = Vm::new();
     let mut line = String::new();
 
     loop {
@@ -113,8 +86,8 @@ pub fn run_repl() {
                 break;
             }
             ":reset" => {
-                interpreter = Interpreter::new();
-                println!("Interpreter reset.");
+                vm = Vm::new();
+                println!("VM reset.");
                 continue;
             }
             _ => {}
@@ -133,7 +106,14 @@ pub fn run_repl() {
             continue;
         }
 
-        if let Err(e) = interpreter.interpret(stmts) {
+        let proto = match Compiler::compile(&stmts) {
+            Ok(p) => p,
+            Err(e) => {
+                eprintln!("Compile Error: {}", e);
+                continue;
+            }
+        };
+        if let Err(e) = vm.run(std::rc::Rc::new(proto)) {
             eprintln!("Error: {}", e);
         }
     }

aster-core/src/parser/parser.rs

@@ -54,6 +54,10 @@ impl Parser {
             self.continue_statement()
         } else if self.match_kind(&[TokenKind::Return]) {
             self.return_statement()
+        } else if self.match_kind(&[TokenKind::Try]) {
+            self.try_statement()
+        } else if self.match_kind(&[TokenKind::Throw]) {
+            self.throw_statement()
         } else if self.match_kind(&[TokenKind::LeftBrace]) {
             Ok(Stmt::Block(self.block()?))
         } else {
@@ -201,6 +205,39 @@ impl Parser {
         Ok(Stmt::Return(value))
     }
 
+    fn try_statement(&mut self) -> Result<Stmt, RuntimeError> {
+        self.consume(TokenKind::LeftBrace, "Expected '{' after 'try'.")?;
+        let body = self.block()?;
+
+        let mut catch_var = None;
+        let mut catch_body = None;
+        if self.match_kind(&[TokenKind::Catch]) {
+            self.consume(TokenKind::LeftParen, "Expected '(' after 'catch'.")?;
+            catch_var = Some(self.consume_ident("Expected exception variable.")?);
+            self.consume(TokenKind::RightParen, "Expected ')' after catch variable.")?;
+            self.consume(TokenKind::LeftBrace, "Expected '{' before catch body.")?;
+            catch_body = Some(self.block()?);
+        }
+
+        let mut finally_body = None;
+        if self.match_kind(&[TokenKind::Finally]) {
+            self.consume(TokenKind::LeftBrace, "Expected '{' after 'finally'.")?;
+            finally_body = Some(self.block()?);
+        }
+
+        if catch_var.is_none() && finally_body.is_none() {
+            return Err(RuntimeError::parse("Expected 'catch' or 'finally' after 'try'.", self.peek().clone()));
+        }
+
+        Ok(Stmt::Try { body, catch_var, catch_body, finally_body })
+    }
+
+    fn throw_statement(&mut self) -> Result<Stmt, RuntimeError> {
+        let expr = self.expression()?;
+        self.match_kind(&[TokenKind::Semicolon]); // 分号可选
+        Ok(Stmt::Throw(expr))
+    }
+
     fn block(&mut self) -> Result<Vec<Stmt>, RuntimeError> {
         let mut statements = Vec::new();
 
@@ -616,7 +653,9 @@ impl Parser {
                 | TokenKind::For
                 | TokenKind::Return
                 | TokenKind::Break
-                | TokenKind::Continue => return,
+                | TokenKind::Continue
+                | TokenKind::Try
+                | TokenKind::Throw => return,
                 _ => {
                     self.advance();
                 }

aster-core/src/runtime/builtins/core.rs

@@ -1,7 +1,7 @@
 //! 标准库：core（len, typeof, push, pop）
 
 use crate::error::RuntimeError;
-use crate::interpreter::{Runtime, Value};
+use crate::runtime::{Runtime, Value};
 
 pub fn len(_runtime: &mut dyn Runtime, args: Vec<Value>) -> Result<Value, RuntimeError> {
     if args.is_empty() {

aster-core/src/runtime/builtins/io.rs

@@ -1,7 +1,7 @@
 //! 标准库：io（print, input）
 
 use crate::error::RuntimeError;
-use crate::interpreter::{Runtime, Value};
+use crate::runtime::{Runtime, Value};
 
 pub fn print(_interp: &mut dyn Runtime, args: Vec<Value>) -> Result<Value, RuntimeError> {
     for arg in args.iter() {

aster-core/src/runtime/builtins/mod.rs

@@ -0,0 +1,45 @@
+//! Builtin function modules.
+
+pub mod core;
+pub mod io;
+pub mod os;
+pub mod string;
+
+use crate::runtime::Value;
+use std::cell::RefCell;
+use std::collections::HashMap;
+use std::rc::Rc;
+
+/// Register all standard library functions into a HashMap.
+pub fn register_all(map: &mut HashMap<String, Value>) {
+    // io
+    let mut io_map = HashMap::new();
+    io_map.insert("print".into(), Value::NativeFunction(Rc::new(io::print)));
+    io_map.insert("input".into(), Value::NativeFunction(Rc::new(io::input)));
+    map.insert("io".into(), Value::Object(Rc::new(RefCell::new(io_map))));
+    map.insert("print".into(), Value::NativeFunction(Rc::new(io::print)));
+    map.insert("input".into(), Value::NativeFunction(Rc::new(io::input)));
+
+    // os
+    let mut os_map = HashMap::new();
+    os_map.insert("clock".into(), Value::NativeFunction(Rc::new(os::clock)));
+    map.insert("os".into(), Value::Object(Rc::new(RefCell::new(os_map))));
+    map.insert("clock".into(), Value::NativeFunction(Rc::new(os::clock)));
+
+    // core
+    map.insert("len".into(), Value::NativeFunction(Rc::new(core::len)));
+    map.insert("typeof".into(), Value::NativeFunction(Rc::new(core::typeof_fn)));
+    map.insert("push".into(), Value::NativeFunction(Rc::new(core::push)));
+    map.insert("pop".into(), Value::NativeFunction(Rc::new(core::pop)));
+
+    // string
+    map.insert("split".into(), Value::NativeFunction(Rc::new(string::split)));
+    map.insert("trim".into(), Value::NativeFunction(Rc::new(string::trim)));
+    map.insert("substring".into(), Value::NativeFunction(Rc::new(string::substring)));
+    map.insert("replace".into(), Value::NativeFunction(Rc::new(string::replace)));
+    map.insert("contains".into(), Value::NativeFunction(Rc::new(string::contains)));
+    map.insert("upper".into(), Value::NativeFunction(Rc::new(string::upper)));
+    map.insert("lower".into(), Value::NativeFunction(Rc::new(string::lower)));
+    map.insert("starts_with".into(), Value::NativeFunction(Rc::new(string::starts_with)));
+    map.insert("ends_with".into(), Value::NativeFunction(Rc::new(string::ends_with)));
+}

aster-core/src/runtime/builtins/os.rs

@@ -1,7 +1,7 @@
 //! 标准库：os（clock）
 
 use crate::error::RuntimeError;
-use crate::interpreter::{Runtime, Value};
+use crate::runtime::{Runtime, Value};
 
 pub fn clock(_interp: &mut dyn Runtime, _args: Vec<Value>) -> Result<Value, RuntimeError> {
     Ok(Value::Number(

aster-core/src/runtime/builtins/string.rs

@@ -1,7 +1,7 @@
 //! 标准库：string（split, trim, substring, replace, contains, upper, lower, starts_with, ends_with）
 
 use crate::error::RuntimeError;
-use crate::interpreter::{Runtime, Value};
+use crate::runtime::{Runtime, Value};
 use std::cell::RefCell;
 use std::rc::Rc;
 

aster-core/src/runtime/mod.rs

@@ -0,0 +1,203 @@
+pub mod builtins;
+
+use std::collections::HashMap;
+use std::rc::Rc;
+use std::cell::RefCell;
+use std::fmt;
+
+/// Trait abstracting runtime services that native functions may need.
+pub trait Runtime {
+    fn require(&mut self, path: &str) -> Result<Value, crate::error::RuntimeError>;
+}
+
+pub type NativeFn = Rc<dyn Fn(&mut dyn Runtime, Vec<Value>) -> Result<Value, crate::error::RuntimeError>>;
+
+// ============================================================================
+// Compiled function types
+// ============================================================================
+
+#[derive(Debug, Clone)]
+pub struct FunctionProto {
+    pub name: Option<String>,
+    pub arity: u8,
+    pub code: Vec<u8>,
+    pub constants: Vec<Value>,
+    pub protos: Vec<Rc<FunctionProto>>,
+    pub upvalue_count: u8,
+    pub upvalues: Vec<(bool, u8)>,         // (is_local, index)
+    pub lines: Vec<(usize, usize)>,         // (bytecode_offset, source_line)
+    pub exception_handlers: Vec<ExceptionHandler>,
+}
+
+/// Exception handler entry: defines a try-catch-finally region.
+#[derive(Debug, Clone)]
+pub struct ExceptionHandler {
+    pub try_start: usize,    // inclusive
+    pub try_end: usize,      // exclusive
+    pub catch_ip: usize,     // catch handler IP (0 if no catch clause)
+    pub catch_slot: u8,      // local slot for catch variable (0 if no catch)
+    pub finally_ip: usize,   // finally rethrow entry (0 if no finally)
+}
+
+impl FunctionProto {
+    pub fn new(name: Option<String>) -> Self {
+        Self {
+            name,
+            arity: 0,
+            code: Vec::new(),
+            constants: Vec::new(),
+            protos: Vec::new(),
+            upvalue_count: 0,
+            upvalues: Vec::new(),
+            lines: Vec::new(),
+            exception_handlers: Vec::new(),
+        }
+    }
+
+    pub fn add_constant(&mut self, val: Value) -> u16 {
+        for (i, c) in self.constants.iter().enumerate() {
+            if values_eq(c, &val) {
+                return i as u16;
+            }
+        }
+        let idx = self.constants.len();
+        self.constants.push(val);
+        idx as u16
+    }
+}
+
+fn values_eq(a: &Value, b: &Value) -> bool {
+    match (a, b) {
+        (Value::Number(x), Value::Number(y)) => (x - y).abs() < f64::EPSILON,
+        (Value::String(x), Value::String(y)) => x == y,
+        (Value::Bool(x), Value::Bool(y)) => x == y,
+        (Value::Nil, Value::Nil) => true,
+        _ => false,
+    }
+}
+
+/// An upvalue — a reference to a local variable in an enclosing function.
+#[derive(Debug, Clone)]
+pub struct UpvalueObj {
+    pub location: usize,
+    pub closed: Option<Value>,
+}
+
+/// A runtime closure: compiled function proto + captured upvalues.
+#[derive(Debug, Clone)]
+pub struct Closure {
+    pub proto: Rc<FunctionProto>,
+    pub upvalues: Vec<Rc<RefCell<UpvalueObj>>>,
+}
+
+// ============================================================================
+// Value
+// ============================================================================
+
+#[derive(Clone)]
+pub enum Value {
+    Number(f64),
+    String(String),
+    Bool(bool),
+    Nil,
+    Object(Rc<RefCell<HashMap<String, Value>>>),
+    Array(Rc<RefCell<Vec<Value>>>),
+    Function(Rc<Closure>),
+    NativeFunction(NativeFn),
+}
+
+impl Value {
+    pub fn get(&self, key: &str) -> Option<Value> {
+        match self {
+            Value::Object(obj) => obj.borrow().get(key).cloned(),
+            _ => None,
+        }
+    }
+
+    pub fn set(&self, key: &str, val: Value) -> Result<(), crate::error::RuntimeError> {
+        match self {
+            Value::Object(obj) => {
+                obj.borrow_mut().insert(key.to_string(), val);
+                Ok(())
+            },
+            _ => Err(crate::error::RuntimeError::RuntimeError {
+                message: "Only objects have properties".to_string(),
+                token: None,
+            }),
+        }
+    }
+}
+
+impl std::fmt::Debug for Value {
+    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+        match self {
+            Value::Number(n) => write!(f, "Number({:?})", n),
+            Value::String(s) => write!(f, "String({:?})", s),
+            Value::Bool(b) => write!(f, "Bool({:?})", b),
+            Value::Nil => write!(f, "Nil"),
+            Value::Object(_) => write!(f, "Object(...)"),
+            Value::Array(_) => write!(f, "Array(...)"),
+            Value::Function(_) => write!(f, "Function(...)"),
+            Value::NativeFunction(_) => write!(f, "NativeFunction(...)"),
+        }
+    }
+}
+
+impl Value {
+    fn fmt_element(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        match self {
+            Value::String(s) => write!(f, "\"{}\"", s),
+            other => write!(f, "{}", other),
+        }
+    }
+}
+
+impl fmt::Display for Value {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        match self {
+            Value::Number(n) => write!(f, "{}", n),
+            Value::String(s) => write!(f, "{}", s),
+            Value::Bool(b) => write!(f, "{}", b),
+            Value::Nil => write!(f, "nil"),
+            Value::Object(obj) => {
+                let obj = obj.borrow();
+                write!(f, "{{ ")?;
+                for (key, value) in obj.iter() {
+                    write!(f, "{}: ", key)?;
+                    value.fmt_element(f)?;
+                    write!(f, ", ")?;
+                }
+                write!(f, "}}")
+            },
+            Value::Array(arr) => {
+                let arr = arr.borrow();
+                write!(f, "[")?;
+                for (i, val) in arr.iter().enumerate() {
+                    if i > 0 {
+                        write!(f, ", ")?;
+                    }
+                    val.fmt_element(f)?;
+                }
+                write!(f, "]")
+            },
+            Value::Function(_) => write!(f, "<function>"),
+            Value::NativeFunction(_) => write!(f, "<native function>"),
+        }
+    }
+}
+
+/// `require()` builtin — thin wrapper that delegates to `Runtime::require`.
+pub fn require_fn(runtime: &mut dyn Runtime, args: Vec<Value>) -> Result<Value, crate::error::RuntimeError> {
+    let path_str = match args.first() {
+        Some(Value::String(s)) => s.clone(),
+        Some(other) => return Err(crate::error::RuntimeError::RuntimeError {
+            message: format!("require() expects a string argument, got {}", other),
+            token: None,
+        }),
+        None => return Err(crate::error::RuntimeError::RuntimeError {
+            message: "require() expects 1 argument (string path)".into(),
+            token: None,
+        }),
+    };
+    runtime.require(&path_str)
+}

aster-core/src/vm/compiler.rs

@@ -7,65 +7,17 @@
 use crate::ast::*;
 use crate::ast::expr::{Literal, UnaryOp, BinaryOp, LogicalOp, AssignOp};
 use crate::error::RuntimeError;
-use crate::interpreter::Value;
+use crate::runtime::{Value, FunctionProto, ExceptionHandler};
 use super::opcode::*;
 
 use std::rc::Rc;
 use std::cell::RefCell;
 
-// ============================================================================
-// FunctionProto — compiled function blueprint
-// ============================================================================
-
-#[derive(Debug, Clone)]
-pub struct FunctionProto {
-    pub name: Option<String>,
-    pub arity: u8,
-    pub code: Vec<u8>,
-    pub constants: Vec<Value>,
-    pub upvalue_count: u8,
-    pub lines: Vec<(usize, usize)>, // (bytecode_offset, source_line)
-}
-
-impl FunctionProto {
-    pub fn new(name: Option<String>) -> Self {
-        Self {
-            name,
-            arity: 0,
-            code: Vec::new(),
-            constants: Vec::new(),
-            upvalue_count: 0,
-            lines: Vec::new(),
-        }
-    }
-
-    fn add_constant(&mut self, val: Value) -> u16 {
-        // Check for existing identical constant
-        for (i, c) in self.constants.iter().enumerate() {
-            if values_eq(c, &val) {
-                return i as u16;
-            }
-        }
-        let idx = self.constants.len();
-        self.constants.push(val);
-        idx as u16
-    }
-}
-
-fn values_eq(a: &Value, b: &Value) -> bool {
-    match (a, b) {
-        (Value::Number(x), Value::Number(y)) => (x - y).abs() < f64::EPSILON,
-        (Value::String(x), Value::String(y)) => x == y,
-        (Value::Bool(x), Value::Bool(y)) => x == y,
-        (Value::Nil, Value::Nil) => true,
-        _ => false,
-    }
-}
-
 // ============================================================================
 // Compiler
 // ============================================================================
 
+#[derive(Clone)]
 struct Local {
     name: String,
     depth: u8,       // scope depth where declared; 0 = uninitialized
@@ -73,26 +25,34 @@ struct Local {
     is_const: bool,
 }
 
+#[derive(Clone)]
 struct Upvalue {
     index: u8,
     is_local: bool,  // true = captured from enclosing fn's local; false = from upvalue
+    is_const: bool,  // true = the source variable was declared `const`
+    name: String,    // variable name (for transitive upvalue resolution)
 }
 
 struct LoopContext {
-    start_ip: usize,             // bytecode offset of loop condition
-    break_patches: Vec<usize>,   // jump instruction offsets that need break dest
-    continue_patches: Vec<usize>,// jump instruction offsets that need continue dest
-    scope_depth: u8,             // scope depth when loop started
+    break_patches: Vec<usize>,
+    continue_patches: Vec<usize>,
 }
 
 pub struct Compiler {
     function: FunctionProto,
     locals: Vec<Local>,
-    upvalues: Vec<Upvalue>,
+    /// Upvalues for this function (shared with child for transitive resolution)
+    upvalues: Rc<RefCell<Vec<Upvalue>>>,
+    /// ALL enclosing locals from entire chain (merged, direct parent first)
+    enclosing_locals: Option<Vec<Local>>,
+    /// Direct parent's own locals count (to distinguish parent locals from deeper ones)
+    parent_locals_count: usize,
+    /// Direct parent's upvalues (shared)
+    enclosing_upvalues: Option<Rc<RefCell<Vec<Upvalue>>>>,
+    /// Grandparent's upvalues (shared, for 3-level transitive capture)
+    grandparent_upvalues: Option<Rc<RefCell<Vec<Upvalue>>>>,
     scope_depth: u8,
     loop_stack: Vec<LoopContext>,
-    /// Index into an outer compiler array for upvalue resolution
-    enclosing_idx: Option<usize>,
 }
 
 impl Compiler {
@@ -100,10 +60,13 @@ impl Compiler {
         Self {
             function: FunctionProto::new(name),
             locals: Vec::new(),
-            upvalues: Vec::new(),
+            upvalues: Rc::new(RefCell::new(Vec::new())),
+            enclosing_locals: None,
+            parent_locals_count: 0,
+            enclosing_upvalues: None,
+            grandparent_upvalues: None,
             scope_depth: 0,
             loop_stack: Vec::new(),
-            enclosing_idx: None,
         }
     }
 
@@ -159,6 +122,8 @@ impl Compiler {
             }
             Stmt::Function { name, params, body } => {
                 self.compile_function_decl(name, params, body)?;
+                // DefineGlobal pushes the value back; pop it as this is a statement
+                self.emit_op(OpCode::Pop);
             }
             Stmt::Return(expr) => {
                 if let Some(e) = expr {
@@ -174,6 +139,12 @@ impl Compiler {
             Stmt::Continue => {
                 self.compile_continue()?;
             }
+            Stmt::Try { body, catch_var, catch_body, finally_body } => {
+                self.compile_try(body, catch_var.as_deref(), catch_body.as_ref(), finally_body.as_ref())?;
+            }
+            Stmt::Throw(expr) => {
+                self.compile_throw(expr)?;
+            }
         }
         Ok(())
     }
@@ -181,11 +152,12 @@ impl Compiler {
     fn compile_let(&mut self, name: &str, initializer: &Expr, mutable: bool) -> Result<(), RuntimeError> {
         self.compile_expr(initializer)?;
         if self.scope_depth == 0 {
-            // Global variable
             let name_idx = self.add_string_constant(name);
             emit_u16(&mut self.function.code, OpCode::DefineGlobal, name_idx);
+            self.function.code.push(if mutable { 1 } else { 0 });
+            // DefineGlobal pushes value back; pop it for statement-level let
+            self.emit_op(OpCode::Pop);
         } else {
-            // Local variable
             let slot = self.locals.len() as u8;
             self.locals.push(Local {
                 name: name.to_string(),
@@ -193,6 +165,7 @@ impl Compiler {
                 is_captured: false,
                 is_const: !mutable,
             });
+            // StoreLocal PEEKS the value — it stays on stack as the local
             emit_u8(&mut self.function.code, OpCode::StoreLocal, slot);
         }
         Ok(())
@@ -219,10 +192,8 @@ impl Compiler {
         let exit_jump = self.emit_jump(OpCode::JumpIfFalse);
 
         self.loop_stack.push(LoopContext {
-            start_ip,
             break_patches: Vec::new(),
             continue_patches: Vec::new(),
-            scope_depth: self.scope_depth,
         });
 
         self.compile_stmt(body)?;
@@ -257,10 +228,8 @@ impl Compiler {
         let exit_jump = self.emit_jump(OpCode::JumpIfFalse);
 
         self.loop_stack.push(LoopContext {
-            start_ip,
             break_patches: Vec::new(),
             continue_patches: Vec::new(),
-            scope_depth: self.scope_depth,
         });
 
         self.compile_stmt(body)?;
@@ -289,13 +258,39 @@ impl Compiler {
     }
 
     fn compile_for_in(&mut self, var_name: &str, iterable: &Expr, body: &Stmt) -> Result<(), RuntimeError> {
-        // Evaluate iterable, set up iterator
-        self.compile_expr(iterable)?;
-        emit_op(&mut self.function.code, OpCode::ForInInit);
-        let exit_jump = emit_i16_placeholder(&mut self.function.code, OpCode::ForInNext);
-
-        // New scope for the loop variable
+        // 1. New scope for hidden iterator locals (items, idx)
         self.begin_scope();
+
+        // 2. Evaluate iterable and compute items array
+        self.compile_expr(iterable)?;
+        emit_op(&mut self.function.code, OpCode::ForInInit); // pops iterable, pushes items[]
+
+        // 3. Store items array in a hidden local (peek, no Pop — cleaned by end_scope)
+        let items_slot = self.locals.len() as u8;
+        self.locals.push(Local {
+            name: format!("__iter_items_{}", items_slot),
+            depth: self.scope_depth,
+            is_captured: false,
+            is_const: false,
+        });
+        emit_u8(&mut self.function.code, OpCode::StoreLocal, items_slot);
+
+        // 4. Initialize index = 0 in hidden local
+        let idx_slot = self.locals.len() as u8;
+        self.locals.push(Local {
+            name: format!("__iter_idx_{}", idx_slot),
+            depth: self.scope_depth,
+            is_captured: false,
+            is_const: false,
+        });
+        let zero_idx = self.add_constant(Value::Number(0.0));
+        emit_u16(&mut self.function.code, OpCode::LoadConst, zero_idx);
+        emit_u8(&mut self.function.code, OpCode::StoreLocal, idx_slot);
+
+        // 5. ForInNext: reads items[idx_slot], idx[idx_slot], pushes element
+        let forin_loc = self.emit_forin_next(items_slot, idx_slot);
+
+        // 6. Store loop variable in a local (peek, value stays on stack)
         let loop_var_slot = self.locals.len() as u8;
         self.locals.push(Local {
             name: var_name.to_string(),
@@ -305,64 +300,54 @@ impl Compiler {
         });
         emit_u8(&mut self.function.code, OpCode::StoreLocal, loop_var_slot);
 
-        let start_ip = self.function.code.len();
-
+        // 7. Loop body (can resolve var_name to loop_var_slot)
         self.loop_stack.push(LoopContext {
-            start_ip,
             break_patches: Vec::new(),
             continue_patches: Vec::new(),
-            scope_depth: self.scope_depth,
         });
 
         self.compile_stmt(body)?;
 
-        // Patch continue → loop back
+        // Patch continue
         let continue_ip = self.function.code.len();
         let loop_ctx = self.loop_stack.pop().unwrap();
         for patch in loop_ctx.continue_patches {
             self.patch_jump_to(patch, continue_ip);
         }
 
-        // Jump back to ForInNext
-        self.emit_loop_jump(start_ip - 3); // jump back to the ForInNext instruction
-        let exit_ip = self.function.code.len();
-        self.patch_jump_to(exit_jump, exit_ip);
+        // 8. Pop loop var element and remove from tracking
+        self.emit_op(OpCode::Pop);
+        self.locals.pop(); // loop_var_slot
 
+        // 9. Jump back to ForInNext (next iteration re-adds loop var via StoreLocal)
+        self.emit_loop_jump(forin_loc);
+
+        // 10. Exit target: patch ForInNext exit and break jumps
+        let exit_ip = self.function.code.len();
+        self.patch_forin_jump(forin_loc, exit_ip);
         for patch in loop_ctx.break_patches {
-            self.patch_jump(patch);
+            self.patch_jump_to(patch, exit_ip);
         }
 
-        // Pop the loop variable
-        self.emit_op(OpCode::Pop);
-        // Pop the iterator state (2 values: iterable ref + index)
-        self.emit_op(OpCode::Pop);
+        // 11. Pop loop var (ForInNext pushes Nil on exit; break leaves element on stack)
         self.emit_op(OpCode::Pop);
 
+        // 12. End scope: pops items_slot + idx_slot values (left by StoreLocal peek)
         self.end_scope();
         Ok(())
     }
 
     fn compile_function_decl(&mut self, name: &str, params: &[String], body: &[Stmt]) -> Result<(), RuntimeError> {
         let proto = self.compile_nested_function(Some(name.to_string()), params, body)?;
-        let const_idx = self.function.add_constant(Value::Function(Rc::new(
-            crate::interpreter::Function {
-                params: params.to_vec(),
-                body: body.to_vec(),
-                env: Rc::new(RefCell::new(crate::interpreter::Env::new(None))),
-                name: Some(name.to_string()),
-            }
-        )));
-        // For now, we also need to store the proto for the VM to use.
-        // We'll store it as a special constant.
+        let upvalues = proto.upvalues.clone();
         let proto_idx = self.add_function_proto_constant(proto);
-
-        // Emit Closure opcode with upvalues
-        self.emit_closure(proto_idx);
+        self.emit_closure(proto_idx, &upvalues);
 
         // Bind to name
         if self.scope_depth == 0 {
             let name_idx = self.add_string_constant(name);
             emit_u16(&mut self.function.code, OpCode::DefineGlobal, name_idx);
+            self.function.code.push(1); // mutable=true for fn declarations
         } else {
             let slot = self.locals.len() as u8;
             self.locals.push(Local {
@@ -396,6 +381,87 @@ impl Compiler {
         Ok(())
     }
 
+    fn compile_throw(&mut self, expr: &Expr) -> Result<(), RuntimeError> {
+        self.compile_expr(expr)?;
+        self.emit_op(OpCode::Throw);
+        Ok(())
+    }
+
+    fn compile_try(
+        &mut self,
+        body: &[Stmt],
+        catch_var: Option<&str>,
+        catch_body: Option<&Vec<Stmt>>,
+        finally_body: Option<&Vec<Stmt>>,
+    ) -> Result<(), RuntimeError> {
+        let try_start = self.function.code.len();
+
+        // Compile try body
+        self.begin_scope();
+        self.compile_stmts(body)?;
+        self.end_scope();
+        let try_end = self.function.code.len();
+
+        // ── Normal path: jump past catch to finally (or end) ──
+        let skip_catch = self.emit_jump(OpCode::Jump);
+
+        // ── Catch handler (entry via unwind) ──
+        let (catch_ip, catch_slot) = if let (Some(var), Some(cb)) = (catch_var, catch_body) {
+            let ip = self.function.code.len();
+            self.begin_scope();
+            let slot = self.locals.len() as u8;
+            self.locals.push(Local {
+                name: var.to_string(),
+                depth: self.scope_depth,
+                is_captured: false,
+                is_const: false,
+            });
+            // VM pushes exception value before jumping here; StoreLocal peeks it
+            emit_u8(&mut self.function.code, OpCode::StoreLocal, slot);
+            self.compile_stmts(cb)?;
+            self.end_scope();
+            (ip, slot)
+        } else {
+            (0, 0)
+        };
+        self.patch_jump(skip_catch);
+
+        // ── Finally: inline for success paths (try/catch fall through here) ──
+        let finally_block_ip = if let Some(fb) = finally_body {
+            let ip = self.function.code.len();
+            self.begin_scope();
+            self.compile_stmts(fb)?;
+            self.end_scope();
+            let done_jump = self.emit_jump(OpCode::Jump);
+
+            // ── Finally rethrow entry (for exception path) ──
+            let rethrow_ip = self.function.code.len();
+            // Duplicate finally body for exception path
+            self.begin_scope();
+            self.compile_stmts(fb)?;
+            self.end_scope();
+            self.emit_op(OpCode::Throw); // re-throw after finally
+
+            self.patch_jump(done_jump);
+            (ip, rethrow_ip)
+        } else {
+            (0, 0)
+        };
+
+        let (_, rethrow_ip) = finally_block_ip;
+
+        // Register exception handler
+        self.function.exception_handlers.push(ExceptionHandler {
+            try_start,
+            try_end,
+            catch_ip,
+            catch_slot,
+            finally_ip: rethrow_ip,
+        });
+
+        Ok(())
+    }
+
     // ========================================================================
     // Expression compilation
     // ========================================================================
@@ -447,17 +513,8 @@ impl Compiler {
         }
         // Try to resolve as upvalue
         if let Some(upvalue_idx) = self.resolve_upvalue(name) {
-            // Upvalue access: LoadUpvalue is LoadLocal with slot = upvalue-local-marker
-            // For simplicity, we use a convention: upvalues are locals with special marking.
-            // Actually, we need a dedicated LoadUpvalue opcode. Let's add it...
-            // For now, store upvalues at "local slots" offset by 256.
-            emit_u16(&mut self.function.code, OpCode::LoadConst, 0xFFFF); // placeholder
-            // We'll handle upvalues properly when we have LoadUpvalue
-            // TODO: Add LoadUpvalue opcode
-            return Err(RuntimeError::RuntimeError {
-                message: format!("Upvalue '{}' not yet supported", name),
-                token: None,
-            });
+            emit_u8(&mut self.function.code, OpCode::LoadUpvalue, upvalue_idx);
+            return Ok(());
         }
         // Fall back to global
         let name_idx = self.add_string_constant(name);
@@ -470,7 +527,24 @@ impl Compiler {
             // Simple assignment
             self.compile_expr(value)?;
             if let Some(slot) = self.resolve_local(name) {
+                // Check const for local
+                if self.locals[slot as usize].is_const {
+                    return Err(RuntimeError::RuntimeError {
+                        message: format!("Cannot reassign constant '{}'", name),
+                        token: None,
+                    });
+                }
                 emit_u8(&mut self.function.code, OpCode::StoreLocal, slot);
+            } else if let Some(uv_idx) = self.resolve_upvalue(name) {
+                // Check const for upvalue
+                let upvalues = self.upvalues.borrow();
+                if upvalues[uv_idx as usize].is_const {
+                    return Err(RuntimeError::RuntimeError {
+                        message: format!("Cannot reassign constant '{}'", name),
+                        token: None,
+                    });
+                }
+                emit_u8(&mut self.function.code, OpCode::StoreUpvalue, uv_idx);
             } else {
                 let name_idx = self.add_string_constant(name);
                 emit_u16(&mut self.function.code, OpCode::StoreGlobal, name_idx);
@@ -489,9 +563,12 @@ impl Compiler {
             if let Some(slot) = self.resolve_local(name) {
                 emit_u8(&mut self.function.code, OpCode::CompoundAssignLocal, slot);
                 self.function.code.push(compound_op as u8);
+            } else if let Some(uv_idx) = self.resolve_upvalue(name) {
+                emit_u8(&mut self.function.code, OpCode::CompoundAssignUpvalue, uv_idx);
+                self.function.code.push(compound_op as u8);
             } else {
                 let name_idx = self.add_string_constant(name);
-                emit_u16(&mut self.function.code, OpCode::CompoundAssignProp, name_idx);
+                emit_u16(&mut self.function.code, OpCode::CompoundAssignGlobal, name_idx);
                 self.function.code.push(compound_op as u8);
             }
         }
@@ -513,16 +590,11 @@ impl Compiler {
             emit_u16(&mut self.function.code, OpCode::SetProperty, name_idx);
         } else {
             // Compound property set: object.name op= value
-            // Strategy: load object, dup, get property as current value,
-            // load rhs, apply op, set property
+            // CompoundAssignProp handler does get_property internally
             self.compile_expr(object)?;
-            self.emit_op(OpCode::Dup);
-            let name_idx = self.add_string_constant(name);
-            emit_u16(&mut self.function.code, OpCode::GetProperty, name_idx); // current value
             self.compile_expr(value)?; // rhs
             let compound_op = assign_op_to_compound(op);
-            self.function.code.push(compound_op as u8);
-            // Now stack: object, current_val, rhs → set property
+            let name_idx = self.add_string_constant(name);
             emit_u16(&mut self.function.code, OpCode::CompoundAssignProp, name_idx);
             self.function.code.push(compound_op as u8);
         }
@@ -643,27 +715,33 @@ impl Compiler {
 
     fn compile_lambda(&mut self, params: &[String], body: &[Stmt]) -> Result<(), RuntimeError> {
         let proto = self.compile_nested_function(None, params, body)?;
+        let upvalues = proto.upvalues.clone();
         let proto_idx = self.add_function_proto_constant(proto);
-        self.emit_closure(proto_idx);
+        self.emit_closure(proto_idx, &upvalues);
         Ok(())
     }
 
     /// Compile a nested function (lambda or function declaration) and return its proto.
     fn compile_nested_function(&mut self, name: Option<String>, params: &[String], body: &[Stmt]) -> Result<FunctionProto, RuntimeError> {
         let mut child = Compiler::new(name);
-        child.enclosing_idx = Some(0); // placeholder — we handle upvalues differently
+        // Build merged enclosing locals: our locals + our enclosing chain
+        let mut all_locals = self.locals.clone();
+        if let Some(ref enc) = self.enclosing_locals {
+            all_locals.extend(enc.iter().cloned());
+        }
+        child.enclosing_locals = Some(all_locals);
+        child.parent_locals_count = self.locals.len();
+        child.enclosing_upvalues = Some(Rc::clone(&self.upvalues));
+        child.grandparent_upvalues = self.enclosing_upvalues.clone();
 
-        // Add params as locals
+        // Add params as locals without StoreLocal — they're already on stack from Call
         for param in params {
-            let slot = child.locals.len() as u8;
             child.locals.push(Local {
                 name: param.clone(),
                 depth: 1, // params are at scope depth 1 (function body)
                 is_captured: false,
                 is_const: false,
             });
-            // Params are already on stack from Call; StoreLocal just peeks
-            emit_u8(&mut child.function.code, OpCode::StoreLocal, slot);
         }
         child.function.arity = params.len() as u8;
 
@@ -676,11 +754,19 @@ impl Compiler {
         child.emit_op(OpCode::LoadNil);
         child.emit_op(OpCode::Return);
 
-        // Resolve upvalues: for each variable reference in the child that wasn't
-        // resolved locally, check if it exists in the parent's locals/upvalues.
-        // (We handle this lazily in compile_variable for now — if not local, try upvalue.)
+        // Mark captured locals in the parent compiler
+        for uv in child.upvalues.borrow().iter() {
+            if uv.is_local {
+                if let Some(local) = self.locals.get_mut(uv.index as usize) {
+                    local.is_captured = true;
+                }
+            }
+        }
 
-        child.function.upvalue_count = child.upvalues.len() as u8;
+        let child_upvalues = child.upvalues.borrow();
+        child.function.upvalue_count = child_upvalues.len() as u8;
+        child.function.upvalues = child_upvalues.iter().map(|uv| (uv.is_local, uv.index)).collect();
+        drop(child_upvalues);
         Ok(child.function)
     }
 
@@ -694,16 +780,18 @@ impl Compiler {
 
     fn end_scope(&mut self) {
         self.scope_depth -= 1;
-        // Pop locals that are going out of scope
+        // Pop locals that are going out of scope (except captured ones)
         let mut pop_count = 0u8;
         while let Some(local) = self.locals.last() {
             if local.depth > self.scope_depth {
                 if local.is_captured {
-                    // Close upvalue instead of pop
-                    // (For now, just pop — upvalue closing handled in VM)
-                }
+                    // Don't pop — the upvalue still needs it on the stack
+                    // The VM will close the upvalue when the function returns
+                    self.locals.pop();
+                } else {
                     self.locals.pop();
                     pop_count += 1;
+                }
             } else {
                 break;
             }
@@ -728,9 +816,117 @@ impl Compiler {
     }
 
     /// Try to resolve a variable as an upvalue from enclosing functions.
+    /// Returns the upvalue index in this function's upvalues list.
     fn resolve_upvalue(&mut self, name: &str) -> Option<u8> {
-        // For now, we don't have enclosing compiler access.
-        // Upvalues will be fully implemented in a follow-up.
+        // Check if already captured
+        for (j, uv) in self.upvalues.borrow().iter().enumerate() {
+            if uv.name == name {
+                return Some(j as u8);
+            }
+        }
+        // Check all enclosing locals (merged chain: parent, grandparent, ...)
+        if let Some(ref enclosing_locals) = self.enclosing_locals {
+            for (i, local) in enclosing_locals.iter().enumerate().rev() {
+                if local.name == name && local.depth > 0 {
+                    if i < self.parent_locals_count {
+                        // Found in direct parent's locals → capture as upvalue
+                        let idx = self.upvalues.borrow().len() as u8;
+                        self.upvalues.borrow_mut().push(Upvalue {
+                            index: i as u8, is_local: true,
+                            is_const: local.is_const,
+                            name: name.to_string()
+                        });
+                        return Some(idx);
+                    } else {
+                        // Found deeper than parent. Need to create upvalue chain.
+                        if let Some(ref enc_upvalues) = self.enclosing_upvalues {
+                            // Check if parent already has this upvalue
+                            let parent_uv_idx = {
+                                let enc = enc_upvalues.borrow();
+                                enc.iter().position(|uv| uv.name == name).map(|p| p as u8)
+                            };
+                            let parent_idx = match parent_uv_idx {
+                                Some(idx) => idx,
+                                None => {
+                                    // Add upvalue to parent's list.
+                                    // The parent sees this variable at a certain index in its own
+                                    // enclosing_locals. That index is (i - self.parent_locals_count)
+                                    // in the merged list, which corresponds to the same variable
+                                    // in the parent's enclosing_locals.
+                                    let enc_idx = enc_upvalues.borrow().len() as u8;
+
+                                    // If we have grandparent_upvalues, the parent's upvalue
+                                    // should be transitive (is_local=false), and we need to
+                                    // ensure grandparent has it too.
+                                    if let Some(ref gp_upvalues) = self.grandparent_upvalues {
+                                        // Ensure grandparent has the upvalue first
+                                        let gp_idx = {
+                                            let gp = gp_upvalues.borrow();
+                                            gp.iter().position(|uv| uv.name == name).map(|p| p as u8)
+                                        };
+                                        let gp_idx = match gp_idx {
+                                            Some(idx) => idx,
+                                            None => {
+                                                let idx = gp_upvalues.borrow().len() as u8;
+                                                // Grandparent captures this as a local
+                                                // (it's directly in the grandparent's enclosing scope)
+                                                gp_upvalues.borrow_mut().push(Upvalue {
+                                                    index: (i - self.parent_locals_count) as u8,
+                                                    is_local: true,
+                                                    is_const: false, // can't easily resolve const-ness at this depth
+                                                    name: name.to_string()
+                                                });
+                                                idx
+                                            }
+                                        };
+                                        // Parent's upvalue is transitive through grandparent
+                                        let gp_uv_is_const = gp_upvalues.borrow()[gp_idx as usize].is_const;
+                                        enc_upvalues.borrow_mut().push(Upvalue {
+                                            index: gp_idx,
+                                            is_local: false,
+                                            is_const: gp_uv_is_const,
+                                            name: name.to_string()
+                                        });
+                                    } else {
+                                        // No grandparent — parent captures directly as local
+                                        enc_upvalues.borrow_mut().push(Upvalue {
+                                            index: (i - self.parent_locals_count) as u8,
+                                            is_local: true,
+                                            is_const: local.is_const,
+                                            name: name.to_string()
+                                        });
+                                    }
+                                    enc_idx
+                                }
+                            };
+                            // Add transitive upvalue in self pointing to parent's
+                            let parent_uv_is_const = enc_upvalues.borrow()[parent_idx as usize].is_const;
+                            let idx = self.upvalues.borrow().len() as u8;
+                            self.upvalues.borrow_mut().push(Upvalue {
+                                index: parent_idx, is_local: false,
+                                is_const: parent_uv_is_const,
+                                name: name.to_string()
+                            });
+                            return Some(idx);
+                        }
+                    }
+                }
+            }
+        }
+        // Check parent's upvalues (transitive closure over 2 levels)
+        if let Some(ref enclosing_upvalues) = self.enclosing_upvalues {
+            for uv in enclosing_upvalues.borrow().iter().rev() {
+                if uv.name == name {
+                    let idx = self.upvalues.borrow().len() as u8;
+                    self.upvalues.borrow_mut().push(Upvalue {
+                        index: uv.index, is_local: false,
+                        is_const: uv.is_const,
+                        name: name.to_string()
+                    });
+                    return Some(idx);
+                }
+            }
+        }
         None
     }
 
@@ -759,13 +955,28 @@ impl Compiler {
         emit_i16(&mut self.function.code, OpCode::Jump, offset as i16);
     }
 
-    fn emit_closure(&mut self, proto_idx: u16) {
+    fn emit_forin_next(&mut self, items_slot: u8, idx_slot: u8) -> usize {
+        let loc = self.function.code.len();
+        let code = &mut self.function.code;
+        code.push(OpCode::ForInNext as u8);
+        code.push(items_slot);
+        code.push(idx_slot);
+        code.push(0xFF); // placeholder offset low
+        code.push(0x7F); // placeholder offset high
+        loc
+    }
+
+    fn emit_closure(&mut self, proto_idx: u16, upvalues: &[(bool, u8)]) {
         let code = &mut self.function.code;
         code.push(OpCode::Closure as u8);
         code.push((proto_idx & 0xFF) as u8);
         code.push(((proto_idx >> 8) & 0xFF) as u8);
-        // No upvalues yet
-        code.push(0u8); // upvalue count = 0 for now
+        let upvalue_count = upvalues.len() as u8;
+        code.push(upvalue_count);
+        for &(is_local, index) in upvalues {
+            code.push(if is_local { 1u8 } else { 0u8 });
+            code.push(index);
+        }
     }
 
     fn patch_jump(&mut self, jump_loc: usize) {
@@ -782,6 +993,18 @@ impl Compiler {
         code[jump_loc + 2] = ((offset >> 8) & 0xFF) as u8;
     }
 
+    /// Patch ForInNext's exit offset (at jump_loc + 3, +4)
+    fn patch_forin_jump(&mut self, forin_loc: usize, target: usize) {
+        let offset = target as isize - forin_loc as isize;
+        let code = &mut self.function.code;
+        code[forin_loc + 3] = (offset & 0xFF) as u8;
+        code[forin_loc + 4] = ((offset >> 8) & 0xFF) as u8;
+    }
+
+    fn add_constant(&mut self, val: Value) -> u16 {
+        self.function.add_constant(val)
+    }
+
     // ========================================================================
     // Constant pool helpers
     // ========================================================================
@@ -791,20 +1014,10 @@ impl Compiler {
     }
 
     fn add_function_proto_constant(&mut self, proto: FunctionProto) -> u16 {
-        // Store compiled proto as a special marker.
-        // We use Value::Nil as placeholder since FunctionProto isn't a Value.
-        // The VM will look up the proto from a separate table.
-        // For now, store the proto's index in a side table.
-        // Actually, let's store it as a string tag that the VM can recognize.
-        // We'll use a dedicated proto storage: just append to a Vec.
-        // But FunctionProto isn't a Value... let's store it inline.
-        // HACK: store proto in constants with a special Object wrapping
-        let idx = self.function.constants.len() as u16;
-        // Use a Value::Object with a special marker
-        // The VM will need to handle this
-        let mut map = std::collections::HashMap::new();
-        map.insert("__proto__".to_string(), Value::String(format!("proto_{}", idx)));
-        self.function.constants.push(Value::Object(Rc::new(RefCell::new(map))));
+        let idx = self.function.protos.len() as u16;
+        self.function.protos.push(Rc::new(proto));
+        // Store proto index as a sentinel value in constants
+        self.function.constants.push(Value::Number(f64::from_bits(idx as u64 | 0x_F000_0000_0000_0000)));
         idx
     }
 }
@@ -823,9 +1036,3 @@ fn assign_op_to_compound(op: &AssignOp) -> CompoundOp {
         AssignOp::Equal => unreachable!(),
     }
 }
-
-fn emit_i16_placeholder(code: &mut Vec<u8>, op: OpCode) -> usize {
-    let loc = code.len();
-    emit_i16(code, op, 0x7FFF);
-    loc
-}

aster-core/src/vm/opcode.rs

@@ -20,6 +20,8 @@ pub enum OpCode {
     // --- Local variables (operand: u8 slot index) ---
     LoadLocal = 6,
     StoreLocal = 7,
+    LoadUpvalue = 42,   // operand: u8 upvalue index
+    StoreUpvalue = 43,  // operand: u8 upvalue index
 
     // --- Global variables (operand: u16 index into constant pool for name) ---
     LoadGlobal = 8,
@@ -76,20 +78,23 @@ pub enum OpCode {
     CompoundAssignLocal = 39,   // operand: u8 slot + u8 compound-op tag
     CompoundAssignProp = 40,    // operand: u16 name idx + u8 compound-op tag
     CompoundAssignIndex = 41,   // operand: u8 compound-op tag
+    CompoundAssignUpvalue = 44, // operand: u8 upvalue idx + u8 compound-op tag
+    CompoundAssignGlobal = 45,  // operand: u16 name idx + u8 compound-op tag
+    Throw = 46,                 // pops exception value, begins stack unwind
 }
 
 impl OpCode {
     pub fn from_u8(byte: u8) -> Option<Self> {
-        if byte <= 41 {
-            // SAFETY: OpCode is #[repr(u8)] with contiguous values 0..=41
-            Some(unsafe { std::mem::transmute::<u8, OpCode>(byte) })
-        } else {
-            None
+        match byte {
+            0..=41 | 44..=46 => Some(unsafe { std::mem::transmute::<u8, OpCode>(byte) }),
+            42 => Some(OpCode::LoadUpvalue),
+            43 => Some(OpCode::StoreUpvalue),
+            _ => None,
         }
     }
 
     /// Total number of distinct opcodes
-    pub const COUNT: usize = 42;
+    pub const COUNT: usize = 47;
 }
 
 /// Compound assignment operator tags (used as operand byte after
@@ -168,3 +173,5 @@ pub const SIZE_OP: usize = 1;
 pub const SIZE_U8: usize = 2;
 /// Size in bytes of an opcode with a u16/i16 operand.
 pub const SIZE_U16: usize = 3;
+/// Size in bytes of an opcode with a u16 + u8 operand.
+pub const SIZE_U16_PLUS1: usize = 4;

aster-core/src/vm/tests.rs

@@ -1,8 +1,10 @@
-use crate::interpreter::{Interpreter, Value};
+use crate::runtime::Value;
 use crate::lexer::Lexer;
 use crate::parser::Parser;
+use crate::vm::compiler::Compiler;
+use crate::vm::vm::Vm;
 
-/// Full pipeline: source → tokens → ast → interpret → last expression value.
+/// Full pipeline: source → tokens → ast → compile → vm → last expression value.
 /// Wraps in `let __result = <expr>;` so we can read the value back.
 fn eval_expr(input: &str) -> Value {
     let wrapped = format!("let __result = {};", input);
@@ -10,25 +12,27 @@ fn eval_expr(input: &str) -> Value {
     let mut parser = Parser::new(tokens);
     let (stmts, errors) = parser.parse();
     assert!(errors.is_empty(), "Parse errors: {:?}", errors);
-    let mut interpreter = Interpreter::new();
-    interpreter.interpret(stmts).expect("Runtime error");
-    interpreter.env.borrow().get("__result").expect("No __result in env")
+    let proto = Compiler::compile(&stmts).expect("Compile error");
+    let mut vm = Vm::new();
+    vm.run(std::rc::Rc::new(proto)).expect("Runtime error");
+    vm.get_global("__result").expect("No __result in globals")
 }
 
-/// Full pipeline for multiple statements. Returns the interpreter for env inspection.
-fn run(input: &str) -> Interpreter {
+/// Full pipeline for multiple statements. Returns the VM for state inspection.
+fn run(input: &str) -> Vm {
     let (tokens, _) = Lexer::new(input).tokenize();
     let mut parser = Parser::new(tokens);
     let (stmts, errors) = parser.parse();
     assert!(errors.is_empty(), "Parse errors: {:?}", errors);
-    let mut interpreter = Interpreter::new();
-    interpreter.interpret(stmts).expect("Runtime error");
-    interpreter
+    let proto = Compiler::compile(&stmts).expect("Compile error");
+    let mut vm = Vm::new();
+    vm.run(std::rc::Rc::new(proto)).expect("Runtime error");
+    vm
 }
 
-/// Helper: get a variable from the interpreter's environment.
-fn get_var(interp: &Interpreter, name: &str) -> Value {
-    interp.env.borrow().get(name).unwrap_or(Value::Nil)
+/// Helper: get a variable from the VM's globals.
+fn get_var(vm: &Vm, name: &str) -> Value {
+    vm.get_global(name).unwrap_or(Value::Nil)
 }
 
 /// Helper: assert a number value.
@@ -1733,3 +1737,305 @@ fn eval_require_empty_module() {
         v => panic!("Expected Object, got {:?}", v),
     }
 }
+
+// =========================================================================
+// Exception handling: throw
+// =========================================================================
+
+#[test]
+fn eval_throw_caught() {
+    let vm = run("
+        let result = 'none';
+        try {
+            throw 'caught!';
+        } catch (e) {
+            result = e;
+        }
+    ");
+    match get_var(&vm, "result") {
+        Value::String(s) => assert_eq!(s, "caught!"),
+        v => panic!("Expected String, got {:?}", v),
+    }
+}
+
+#[test]
+fn eval_throw_preserves_value_type() {
+    let vm = run("
+        let msg = '';
+        let code = 0;
+        try { throw 'error'; } catch (e) { msg = e; }
+        try { throw 42; } catch (e) { code = e; }
+    ");
+    match get_var(&vm, "msg") {
+        Value::String(s) => assert_eq!(s, "error"),
+        v => panic!("Expected String, got {:?}", v),
+    }
+    assert_num(&get_var(&vm, "code"), 42.0);
+}
+
+#[test]
+fn eval_throw_caught_correct_handler() {
+    let vm = run("
+        let outer = 'none';
+        let inner = 'none';
+        try {
+            try {
+                throw 'inner';
+            } catch (e) {
+                inner = e;
+            }
+        } catch (e) {
+            outer = e;
+        }
+    ");
+    match get_var(&vm, "inner") {
+        Value::String(s) => assert_eq!(s, "inner"),
+        v => panic!("Expected String, got {:?}", v),
+    }
+    match get_var(&vm, "outer") {
+        Value::String(s) => assert_eq!(s, "none"),
+        v => panic!("Expected String, got {:?}", v),
+    }
+}
+
+// =========================================================================
+// Exception handling: runtime errors caught
+// =========================================================================
+
+#[test]
+fn eval_catch_division_by_zero() {
+    let vm = run("
+        let msg = 'none';
+        try {
+            let x = 1 / 0;
+        } catch (e) {
+            msg = e;
+        }
+    ");
+    match get_var(&vm, "msg") {
+        Value::String(s) => assert!(s.contains("Division by zero") || s.contains("division"), "got: {}", s),
+        v => panic!("Expected String, got {:?}", v),
+    }
+}
+
+#[test]
+fn eval_catch_undefined_variable() {
+    let vm = run("
+        let msg = 'none';
+        try {
+            let x = no_such_var;
+        } catch (e) {
+            msg = e;
+        }
+    ");
+    match get_var(&vm, "msg") {
+        Value::String(s) => assert!(s.contains("Undefined"), "got: {}", s),
+        v => panic!("Expected String, got {:?}", v),
+    }
+}
+
+#[test]
+fn eval_catch_index_out_of_bounds() {
+    let vm = run("
+        let msg = 'none';
+        try {
+            let x = [1, 2][99];
+        } catch (e) {
+            msg = e;
+        }
+    ");
+    match get_var(&vm, "msg") {
+        Value::String(s) => assert!(s.contains("out of bounds"), "got: {}", s),
+        v => panic!("Expected String, got {:?}", v),
+    }
+}
+
+#[test]
+fn eval_catch_call_non_function() {
+    let vm = run("
+        let msg = 'none';
+        try {
+            42();
+        } catch (e) {
+            msg = e;
+        }
+    ");
+    match get_var(&vm, "msg") {
+        Value::String(s) => assert!(s.contains("non-function"), "got: {}", s),
+        v => panic!("Expected String, got {:?}", v),
+    }
+}
+
+#[test]
+fn eval_no_error_runs_normally() {
+    let vm = run("
+        let result = 0;
+        try {
+            result = 42;
+        } catch (e) {
+            result = -1;
+        }
+    ");
+    assert_num(&get_var(&vm, "result"), 42.0);
+}
+
+// =========================================================================
+// Exception handling: finally
+// =========================================================================
+
+#[test]
+fn eval_finally_runs_on_success() {
+    let vm = run("
+        let flag = 0;
+        try {
+            flag = 1;
+        } finally {
+            flag = flag + 10;
+        }
+    ");
+    assert_num(&get_var(&vm, "flag"), 11.0);
+}
+
+#[test]
+fn eval_finally_runs_on_throw() {
+    let vm = run("
+        let flag = 0;
+        let msg = 'none';
+        try {
+            throw 'oops';
+        } catch (e) {
+            msg = e;
+        } finally {
+            flag = flag + 10;
+        }
+    ");
+    match get_var(&vm, "msg") {
+        Value::String(s) => assert_eq!(s, "oops"),
+        v => panic!("Expected String, got {:?}", v),
+    }
+    assert_num(&get_var(&vm, "flag"), 10.0);
+}
+
+#[test]
+fn eval_finally_runs_on_runtime_error() {
+    let vm = run("
+        let flag = 0;
+        let msg = 'none';
+        try {
+            let x = 1 / 0;
+        } catch (e) {
+            msg = 'caught';
+        } finally {
+            flag = 1;
+        }
+    ");
+    match get_var(&vm, "msg") {
+        Value::String(s) => assert_eq!(s, "caught"),
+        v => panic!("Expected String, got {:?}", v),
+    }
+    assert_num(&get_var(&vm, "flag"), 1.0);
+}
+
+#[test]
+fn eval_finally_without_catch() {
+    // try-finally without catch: finally runs, then rethrows
+    let result = std::panic::catch_unwind(|| {
+        run("
+            let flag = 0;
+            try {
+                throw 'boom';
+            } finally {
+                flag = 1;
+            }
+        ");
+    });
+    assert!(result.is_err(), "Expected uncaught exception");
+}
+
+#[test]
+fn eval_nested_try_catch() {
+    let vm = run("
+        let outer = 'none';
+        let inner = 'none';
+        try {
+            try {
+                throw 'inner_error';
+            } catch (e) {
+                inner = e;
+            }
+        } catch (e) {
+            outer = e;
+        }
+    ");
+    match get_var(&vm, "inner") {
+        Value::String(s) => assert_eq!(s, "inner_error"),
+        v => panic!("Expected String, got {:?}", v),
+    }
+    match get_var(&vm, "outer") {
+        Value::String(s) => assert_eq!(s, "none"),
+        v => panic!("Expected String, got {:?}", v),
+    }
+}
+
+#[test]
+fn eval_throw_in_catch_propagates() {
+    let vm = run("
+        let outer = 'none';
+        let inner = 'none';
+        try {
+            try {
+                throw 'first';
+            } catch (e) {
+                inner = e;
+                throw 'second';
+            }
+        } catch (e) {
+            outer = e;
+        }
+    ");
+    match get_var(&vm, "inner") {
+        Value::String(s) => assert_eq!(s, "first"),
+        v => panic!("Expected String, got {:?}", v),
+    }
+    match get_var(&vm, "outer") {
+        Value::String(s) => assert_eq!(s, "second"),
+        v => panic!("Expected String, got {:?}", v),
+    }
+}
+
+#[test]
+fn eval_try_catch_in_function() {
+    let vm = run("
+        fn safe_div(a, b) {
+            try {
+                return a / b;
+            } catch (e) {
+                return -1;
+            }
+        }
+        let r1 = safe_div(10, 2);
+        let r2 = safe_div(10, 0);
+    ");
+    assert_num(&get_var(&vm, "r1"), 5.0);
+    assert_num(&get_var(&vm, "r2"), -1.0);
+}
+
+#[test]
+fn eval_finally_known_limitation_return() {
+    // Note: return/break/continue inside try-finally do NOT yet run finally
+    // (this is a known limitation). This test documents current behavior.
+    let vm = run("
+        let flag = 0;
+        fn test() {
+            try {
+                return 42;
+            } finally {
+                flag = 1;
+            }
+        }
+        let r = test();
+    ");
+    assert_num(&get_var(&vm, "r"), 42.0);
+    // flag stays 0 because finally doesn't run before return (known limitation)
+    assert_num(&get_var(&vm, "flag"), 0.0);
+}

aster-core/src/vm/vm.rs

@@ -4,11 +4,11 @@
 //! call frames. Implements the `Runtime` trait for native function support.
 
 use crate::error::RuntimeError;
-use crate::interpreter::{Value, Runtime};
+use crate::runtime::{Value, Runtime, FunctionProto, Closure, UpvalueObj, ExceptionHandler};
 use crate::lexer::Lexer;
 use crate::parser::Parser;
 use super::opcode::*;
-use super::compiler::{Compiler, FunctionProto};
+use super::compiler::Compiler;
 
 use std::cell::RefCell;
 use std::collections::HashMap;
@@ -18,22 +18,6 @@ use std::rc::Rc;
 // VM data structures
 // ============================================================================
 
-/// An upvalue — a reference to a local variable in an enclosing function.
-#[derive(Debug, Clone)]
-struct UpvalueObj {
-    /// Stack index where the value lives, or usize::MAX if closed
-    location: usize,
-    /// The value, if it has been moved off the stack (closed)
-    closed: Option<Value>,
-}
-
-/// A runtime closure: compiled function proto + captured upvalues.
-#[derive(Debug, Clone)]
-struct Closure {
-    proto: Rc<FunctionProto>,
-    upvalues: Vec<Rc<RefCell<UpvalueObj>>>,
-}
-
 /// A call frame on the VM stack.
 struct CallFrame {
     closure: Rc<Closure>,
@@ -46,10 +30,10 @@ pub struct Vm {
     pub stack: Vec<Value>,
 
     /// Call frames
-    pub frames: Vec<CallFrame>,
+    frames: Vec<CallFrame>,
 
-    /// Script-level globals (top-level let bindings)
-    pub globals: Rc<RefCell<HashMap<String, Value>>>,
+    /// Script-level globals (top-level let/const bindings). Value is (value, is_mutable).
+    pub globals: Rc<RefCell<HashMap<String, (Value, bool)>>>,
 
     /// Builtins (shared across modules)
     pub builtins: Rc<RefCell<HashMap<String, Value>>>,
@@ -61,10 +45,7 @@ pub struct Vm {
     pub current_dir: String,
 
     /// Open upvalues (tracked so closures share the same upvalue object)
-    pub open_upvalues: Vec<Rc<RefCell<UpvalueObj>>>,
-
-    /// Allocated function protos (indexed by the compiler's constant pool index)
-    protos: Vec<Rc<FunctionProto>>,
+    open_upvalues: Vec<Rc<RefCell<UpvalueObj>>>,
 }
 
 impl Vm {
@@ -85,7 +66,6 @@ impl Vm {
                 .map(|p| p.to_string_lossy().to_string())
                 .unwrap_or_else(|_| ".".to_string()),
             open_upvalues: Vec::new(),
-            protos: Vec::new(),
         }
     }
 
@@ -101,6 +81,12 @@ impl Vm {
         self.run(Rc::new(proto))
     }
 
+    /// Look up a global variable by name (for test inspection).
+    pub fn get_global(&self, name: &str) -> Option<Value> {
+        self.globals.borrow().get(name).map(|(v, _)| v.clone())
+            .or_else(|| self.builtins.borrow().get(name).cloned())
+    }
+
     /// Execute a compiled FunctionProto.
     pub fn run(&mut self, proto: Rc<FunctionProto>) -> Result<(), RuntimeError> {
         let closure = Rc::new(Closure {
@@ -123,8 +109,26 @@ impl Vm {
 
     fn execute_loop(&mut self) -> Result<(), RuntimeError> {
         loop {
+            match self.execute_one_step() {
+                Ok(true) => continue,  // more instructions to execute
+                Ok(false) => return Ok(()),  // VM finished
+                Err(runtime_err) => {
+                    // Try to handle as exception
+                    let exc = Value::String(runtime_err.to_string());
+                    self.unwind(exc)?; // Err if no handler found
+                    continue; // Handler found, continue executing
+                }
+            }
+        }
+    }
+
+    /// Execute a single bytecode instruction. Returns:
+    /// - Ok(true): continue the loop
+    /// - Ok(false): VM is done (frames empty)
+    /// - Err(...): runtime error to potentially catch
+    fn execute_one_step(&mut self) -> Result<bool, RuntimeError> {
         if self.frames.is_empty() {
-                return Ok(());
+            return Ok(false);
         }
 
         // Snapshot frame state (must drop borrow before mutating self)
@@ -133,14 +137,15 @@ impl Vm {
 
         if ip >= code_len {
             // End of function — implicit return nil
-                self.frames.pop();
+            let frame = self.frames.pop().unwrap();
+            self.close_upvalues(frame.stack_base);
             if self.frames.is_empty() {
-                    return Ok(());
+                return Ok(false);
             }
-                let base = self.frames.last().unwrap().stack_base;
-                self.stack.truncate(base);
+            // Remove callee + args + function locals, push nil result
+            self.stack.truncate(frame.stack_base.saturating_sub(1));
             self.stack.push(Value::Nil);
-                continue;
+            return Ok(true);
         }
 
         // Clone Rc<FunctionProto> to access code without holding self.frames borrow
@@ -193,15 +198,51 @@ impl Vm {
                 // --- Locals ---
                 OpCode::LoadLocal => {
                     let slot = read_u8(code, ip) as usize;
-                    let val = self.stack[self.frame().stack_base + slot].clone();
+                    let idx = self.frames.last().unwrap().stack_base + slot;
+                    if idx >= self.stack.len() {
+                        return Err(RuntimeError::RuntimeError {
+                            message: format!("LoadLocal: slot {} uninitialized", slot),
+                            token: None,
+                        });
+                    }
+                    let val = self.stack[idx].clone();
                     self.stack.push(val);
                     self.advance_ip(SIZE_U8);
                 }
                 OpCode::StoreLocal => {
                     let slot = read_u8(code, ip) as usize;
-                    let val = self.stack.last().unwrap().clone();
+                    let val = self.stack.last().unwrap().clone(); // peek
                     let base = self.frames.last().unwrap().stack_base;
-                    self.stack[base + slot] = val;
+                    let idx = base + slot;
+                    if idx >= self.stack.len() {
+                        self.stack.resize(idx + 1, Value::Nil);
+                    }
+                    self.stack[idx] = val;
+                    self.advance_ip(SIZE_U8);
+                }
+                OpCode::LoadUpvalue => {
+                    let idx = read_u8(code, ip) as usize;
+                    let uv = Rc::clone(&self.frames.last().unwrap().closure.upvalues[idx]);
+                    let uv_ref = uv.borrow();
+                    let val = if let Some(ref closed) = uv_ref.closed {
+                        closed.clone()
+                    } else {
+                        self.stack[uv_ref.location].clone()
+                    };
+                    drop(uv_ref);
+                    self.stack.push(val);
+                    self.advance_ip(SIZE_U8);
+                }
+                OpCode::StoreUpvalue => {
+                    let idx = read_u8(code, ip) as usize;
+                    let val = self.stack.last().unwrap().clone(); // peek
+                    let uv = Rc::clone(&self.frames.last().unwrap().closure.upvalues[idx]);
+                    let mut uv_ref = uv.borrow_mut();
+                    if let Some(ref mut closed) = uv_ref.closed {
+                        *closed = val;
+                    } else {
+                        self.stack[uv_ref.location] = val;
+                    }
                     self.advance_ip(SIZE_U8);
                 }
 
@@ -209,7 +250,8 @@ impl Vm {
                 OpCode::LoadGlobal => {
                     let name_idx = read_u16(code, ip) as usize;
                     let name = proto_string(&proto, name_idx)?;
-                    let val = self.globals.borrow().get(&name).cloned()
+                    let val = self.globals.borrow().get(&name)
+                        .map(|(v, _)| v.clone())
                         .or_else(|| self.builtins.borrow().get(&name).cloned())
                         .ok_or_else(|| RuntimeError::RuntimeError {
                             message: format!("Undefined variable '{}'", name),
@@ -222,16 +264,31 @@ impl Vm {
                     let name_idx = read_u16(code, ip) as usize;
                     let name = proto_string(&proto,name_idx)?;
                     let val = self.stack.last().unwrap().clone();
-                    self.globals.borrow_mut().insert(name, val);
+                    {
+                        let mut globals = self.globals.borrow_mut();
+                        match globals.get(&name) {
+                            Some((_, false)) => {
+                                return Err(RuntimeError::RuntimeError {
+                                    message: format!("Cannot reassign constant '{}'", name),
+                                    token: None,
+                                });
+                            }
+                            _ => {
+                                // Exists and mutable, or not yet defined — store as mutable
+                                globals.insert(name, (val, true));
+                            }
+                        }
+                    }
                     self.advance_ip(SIZE_U16);
                 }
                 OpCode::DefineGlobal => {
                     let name_idx = read_u16(code, ip) as usize;
                     let name = proto_string(&proto,name_idx)?;
+                    let mutable = code[ip + 3] != 0; // 0 = const, 1 = mutable
                     let val = self.stack.pop().unwrap();
-                    self.globals.borrow_mut().insert(name, val.clone());
+                    self.globals.borrow_mut().insert(name, (val.clone(), mutable));
                     self.stack.push(val);
-                    self.advance_ip(SIZE_U16);
+                    self.advance_ip(SIZE_U16 + 1); // 4 bytes: opcode + u16 + u8
                 }
 
                 // --- Properties ---
@@ -402,31 +459,34 @@ impl Vm {
                     let result = self.stack.pop().unwrap();
                     let frame = self.frames.pop().unwrap();
                     self.close_upvalues(frame.stack_base);
-                    self.stack.truncate(frame.stack_base);
+                    // Remove callee + args + function locals, push return value
+                    self.stack.truncate(frame.stack_base.saturating_sub(1));
                     self.stack.push(result);
                     if self.frames.is_empty() {
-                        return Ok(());
+                        return Ok(false);
                     }
-                    // IP of caller is unchanged (already at next instruction)
                 }
                 OpCode::Closure => {
                     let proto_idx = read_u16(code, ip) as usize;
                     let upvalue_count = code[ip + 3] as usize;
-                    let proto = Rc::clone(&self.protos[proto_idx]);
+                    let proto = proto.protos.get(proto_idx).ok_or_else(|| RuntimeError::RuntimeError {
+                        message: format!("Closure proto index {} out of bounds", proto_idx),
+                        token: None,
+                    })?.clone();
 
-                    // Collect upvalue capture info from bytecode first
+                    // Collect upvalue capture info
                     struct UpCapture { is_local: bool, index: usize }
                     let mut captures: Vec<UpCapture> = Vec::new();
-                    let mut offset = ip + 4;
+                    let mut off = ip + 4;
                     for _ in 0..upvalue_count {
-                        let is_local = code[offset] != 0;
-                        offset += 1;
-                        let index = code[offset] as usize;
-                        offset += 1;
+                        let is_local = code[off] != 0;
+                        off += 1;
+                        let index = code[off] as usize;
+                        off += 1;
                         captures.push(UpCapture { is_local, index });
                     }
 
-                    // Now do the actual captures (no conflicting borrows)
+                    // Do the actual captures
                     let base = self.frames.last().unwrap().stack_base;
                     let parent_upvalues = self.frames.last().unwrap().closure.upvalues.clone();
                     let mut upvalues = Vec::new();
@@ -439,17 +499,9 @@ impl Vm {
                         }
                     }
 
-                    // Store closure (stub for now)
-                    let _closure = Rc::new(Closure { proto, upvalues });
-                    self.stack.push(Value::Function(Rc::new(
-                        crate::interpreter::Function {
-                            params: Vec::new(),
-                            body: Vec::new(),
-                            env: Rc::new(RefCell::new(crate::interpreter::Env::new(None))),
-                            name: None,
-                        }
-                    )));
-                    self.advance_ip_to(offset);
+                    let closure = Rc::new(Closure { proto, upvalues });
+                    self.stack.push(Value::Function(closure));
+                    self.advance_ip_to(off);
                 }
 
                 // --- Object/Array ---
@@ -471,32 +523,49 @@ impl Vm {
                 // --- For-in ---
                 OpCode::ForInInit => {
                     let iterable = self.stack.pop().unwrap();
-                    // Push iterator state: (collection, index)
-                    let iter = Value::Number(0.0);
-                    self.stack.push(iterable);
-                    self.stack.push(iter);
+                    let items = match &iterable {
+                        Value::Array(arr) => arr.borrow().clone(),
+                        Value::Object(obj) => obj.borrow().keys().map(|k| Value::String(k.clone())).collect(),
+                        Value::String(s) => s.chars().map(|c| Value::String(c.to_string())).collect(),
+                        _ => return Err(RuntimeError::RuntimeError {
+                            message: format!("for-in requires an array, object, or string, got {}", iterable),
+                            token: None,
+                        }),
+                    };
+                    self.stack.push(Value::Array(Rc::new(RefCell::new(items))));
                     self.advance_ip(SIZE_OP);
                 }
                 OpCode::ForInNext => {
-                    let exit_offset = read_i16(code, ip) as isize;
-                    let exit_ip = ((ip as isize) + exit_offset) as usize;
-                    let iter_idx = self.stack.pop().unwrap(); // current index
-                    let collection = self.stack.pop().unwrap(); // the iterable
+                    // Encoding: opcode(1) + items_slot(1) + idx_slot(1) + exit_offset(2) = 5
+                    let items_slot = code[ip + 1] as usize;
+                    let idx_slot = code[ip + 2] as usize;
+                    let exit_offset = ((code[ip + 3] as u16) | ((code[ip + 4] as u16) << 8)) as i16;
+                    let exit_ip = ((ip as isize) + exit_offset as isize) as usize;
+                    let base = self.frames.last().unwrap().stack_base;
+
+                    // Read index from local slot
+                    let idx_val = self.stack[base + idx_slot].clone();
+                    let idx = self.as_usize(&idx_val, "for-in index")?;
+                    let items_val = self.stack[base + items_slot].clone();
+
+                    let items = match &items_val {
+                        Value::Array(arr) => arr.borrow(),
+                        _ => return Err(RuntimeError::RuntimeError {
+                            message: "ForInNext: items is not an array".into(),
+                            token: None,
+                        }),
+                    };
 
-                    let idx = self.as_number(&iter_idx)? as usize;
-                    let items = self.for_in_items(&collection);
                     if idx >= items.len() {
-                        // Done iterating — push back state and jump to exit
-                        self.stack.push(collection);
-                        self.stack.push(iter_idx);
+                        // Done: push Nil (keeps stack balanced for Pop at exit)
+                        self.stack.push(Value::Nil);
                         self.advance_ip_to(exit_ip);
                     } else {
-                        // Push back incremented state
-                        self.stack.push(collection);
-                        self.stack.push(Value::Number((idx + 1) as f64));
-                        // Push the current value for the loop body
+                        // Push current element for loop body
                         self.stack.push(items[idx].clone());
-                        self.advance_ip(SIZE_U16);
+                        // Increment index in local slot
+                        self.stack[base + idx_slot] = Value::Number((idx + 1) as f64);
+                        self.advance_ip(5); // SIZE_FORIN_NEXT = 5
                     }
                 }
 
@@ -507,9 +576,16 @@ impl Vm {
                     let compound_op = CompoundOp::from_u8(op_tag).unwrap();
                     let rhs = self.stack.pop().unwrap();
                     let base = self.frames.last().unwrap().stack_base;
-                    let lhs = self.stack[base + slot].clone();
+                    let idx = base + slot;
+                    if idx >= self.stack.len() {
+                        return Err(RuntimeError::RuntimeError {
+                            message: format!("CompoundAssignLocal to uninitialized local {}", slot),
+                            token: None,
+                        });
+                    }
+                    let lhs = self.stack[idx].clone();
                     let result = self.apply_compound_op(lhs, rhs, compound_op)?;
-                    self.stack[base + slot] = result.clone();
+                    self.stack[idx] = result.clone();
                     self.stack.push(result);
                     self.advance_ip(SIZE_U8 + 1);
                 }
@@ -538,18 +614,71 @@ impl Vm {
                     self.stack.push(result);
                     self.advance_ip(SIZE_OP + 1);
                 }
+                OpCode::CompoundAssignUpvalue => {
+                    let uv_idx = read_u8(code, ip) as usize;
+                    let op_tag = code[ip + 2];
+                    let compound_op = CompoundOp::from_u8(op_tag).unwrap();
+                    let rhs = self.stack.pop().unwrap();
+                    let uv = Rc::clone(&self.frames.last().unwrap().closure.upvalues[uv_idx]);
+                    let mut uv_ref = uv.borrow_mut();
+                    let lhs = if let Some(ref closed) = uv_ref.closed {
+                        closed.clone()
+                    } else {
+                        self.stack[uv_ref.location].clone()
+                    };
+                    let result = self.apply_compound_op(lhs, rhs, compound_op)?;
+                    if let Some(ref mut closed) = uv_ref.closed {
+                        *closed = result.clone();
+                    } else {
+                        self.stack[uv_ref.location] = result.clone();
+                    }
+                    drop(uv_ref);
+                    self.stack.push(result);
+                    self.advance_ip(SIZE_U8 + 1);
+                }
+                OpCode::CompoundAssignGlobal => {
+                    let name_idx = read_u16(code, ip) as usize;
+                    let op_tag = code[ip + 3];
+                    let compound_op = CompoundOp::from_u8(op_tag).unwrap();
+                    let rhs = self.stack.pop().unwrap();
+                    let name = proto_string(&proto, name_idx)?;
+                    let lhs = self.globals.borrow().get(&name)
+                        .map(|(v, _)| v.clone())
+                        .or_else(|| self.builtins.borrow().get(&name).cloned())
+                        .ok_or_else(|| RuntimeError::RuntimeError {
+                            message: format!("Undefined variable '{}'", name),
+                            token: None,
+                        })?;
+                    let result = self.apply_compound_op(lhs, rhs, compound_op)?;
+                    // Check const flag (globals tuple stores (value, mutable))
+                    if let Some((_, mutable)) = self.globals.borrow().get(&name) {
+                        if !*mutable {
+                            return Err(RuntimeError::RuntimeError {
+                                message: format!("Cannot reassign constant '{}'", name),
+                                token: None,
+                            });
                         }
                     }
+                    self.globals.borrow_mut().insert(name, (result.clone(), true));
+                    self.stack.push(result);
+                    self.advance_ip(SIZE_U16_PLUS1);
+                }
+                OpCode::Throw => {
+                    let exc = self.stack.pop().unwrap();
+                    self.unwind(exc)?;
+                    // unwind() returns Ok only if it found a handler and jumped there
+                    return Ok(true);
+                }
+        }
+
+        // All ops (except Throw) fall through to here
+        Ok(true)
     }
 
     // ========================================================================
     // IP management
     // ========================================================================
 
-    fn frame(&self) -> &CallFrame {
-        self.frames.last().unwrap()
-    }
-
     fn frame_mut(&mut self) -> &mut CallFrame {
         self.frames.last_mut().unwrap()
     }
@@ -562,6 +691,63 @@ impl Vm {
         self.frame_mut().ip = target;
     }
 
+    // ========================================================================
+    // Exception handling (stack unwind)
+    // ========================================================================
+
+    /// Search for an exception handler covering the current IP.
+    /// Returns the handler and true if a handler was found.
+    fn find_handler(proto: &FunctionProto, ip: usize) -> Option<&ExceptionHandler> {
+        // Search in insertion order: innermost try is compiled (and registered) first,
+        // so forward iteration finds the innermost matching handler first.
+        proto.exception_handlers.iter().find(|h| ip >= h.try_start && ip < h.try_end)
+    }
+
+    /// Unwind the call stack to find an exception handler. On success,
+    /// the VM's IP is set to the handler and execution continues.
+    /// Returns Err if no handler is found (uncaught exception).
+    fn unwind(&mut self, exception: Value) -> Result<(), RuntimeError> {
+        loop {
+            if self.frames.is_empty() {
+                return Err(RuntimeError::RuntimeError {
+                    message: format!("Uncaught exception: {}", exception),
+                    token: None,
+                });
+            }
+
+            let ip = self.frames.last().unwrap().ip;
+            let proto = Rc::clone(&self.frames.last().unwrap().closure.proto);
+
+            if let Some(h) = Self::find_handler(&proto, ip) {
+                if h.finally_ip != 0 {
+                    if h.catch_ip != 0 {
+                        // Has catch: push exception, jump to catch.
+                        // Catch body falls through to inline finally.
+                        self.stack.push(exception);
+                        self.frame_mut().ip = h.catch_ip;
+                        return Ok(());
+                    } else {
+                        // No catch, only finally: push exception, jump to finally
+                        // rethrow entry. The finally body runs, then Throw.
+                        self.stack.push(exception);
+                        self.frame_mut().ip = h.finally_ip;
+                        return Ok(());
+                    }
+                } else if h.catch_ip != 0 {
+                    // Only catch, no finally
+                    self.stack.push(exception);
+                    self.frame_mut().ip = h.catch_ip;
+                    return Ok(());
+                }
+            }
+
+            // No handler — pop frame and continue in caller
+            let frame = self.frames.pop().unwrap();
+            self.close_upvalues(frame.stack_base);
+            self.stack.truncate(frame.stack_base.saturating_sub(1));
+        }
+    }
+
     // ========================================================================
     // Function calls
     // ========================================================================
@@ -570,8 +756,13 @@ impl Vm {
         let callee_idx = self.stack.len() - 1 - arg_count;
         let callee = self.stack[callee_idx].clone();
 
-        match callee {
-            Value::NativeFunction(native_fn) => {
+        match &callee {
+            Value::NativeFunction(_) => {
+                // Get the native function
+                let native_fn = match self.stack[callee_idx].clone() {
+                    Value::NativeFunction(f) => f,
+                    _ => unreachable!(),
+                };
                 // Pop arguments from stack
                 let mut args = Vec::new();
                 for _ in 0..arg_count {
@@ -583,27 +774,18 @@ impl Vm {
                 self.stack.push(result);
                 self.advance_ip(SIZE_U8);
             }
-            Value::Function(f) => {
-                // User-defined function: create new call frame
-                let base = callee_idx; // where the new frame's locals start
-                let new_closure = Rc::new(Closure {
-                    proto: Rc::new(FunctionProto::new(f.name.clone())),
-                    upvalues: Vec::new(),
-                });
+            Value::Function(closure) => {
+                let closure = Rc::clone(closure);
+                // Advance caller's IP past the Call instruction before pushing new frame
+                self.frame_mut().ip += SIZE_U8;
+
+                // Callee is at callee_idx, args start at callee_idx+1
+                let base = callee_idx + 1;
                 self.frames.push(CallFrame {
-                    closure: new_closure,
+                    closure,
                     ip: 0,
                     stack_base: base,
                 });
-                // Arguments are already on the stack at the right position
-                // (they become locals 0..arg_count in the new frame)
-                // The callee itself becomes slot 0 (TODO: handle properly)
-                // For now, this is a stub — full function support needs
-                // proper closure/proto integration
-                return Err(RuntimeError::RuntimeError {
-                    message: "VM user-defined function calls not yet fully implemented".into(),
-                    token: None,
-                });
             }
             _ => {
                 return Err(RuntimeError::RuntimeError {
@@ -653,6 +835,78 @@ impl Vm {
             },
             Value::String(s) => match name {
                 "length" => Ok(Value::Number(s.chars().count() as f64)),
+                "upper" => {
+                    let s = s.clone();
+                    Ok(Value::NativeFunction(Rc::new(move |runtime: &mut dyn Runtime, args: Vec<Value>| {
+                        let mut all_args = vec![Value::String(s.clone())];
+                        all_args.extend(args);
+                        crate::runtime::builtins::string::upper(runtime, all_args)
+                    })))
+                }
+                "lower" => {
+                    let s = s.clone();
+                    Ok(Value::NativeFunction(Rc::new(move |runtime: &mut dyn Runtime, args: Vec<Value>| {
+                        let mut all_args = vec![Value::String(s.clone())];
+                        all_args.extend(args);
+                        crate::runtime::builtins::string::lower(runtime, all_args)
+                    })))
+                }
+                "trim" => {
+                    let s = s.clone();
+                    Ok(Value::NativeFunction(Rc::new(move |runtime: &mut dyn Runtime, args: Vec<Value>| {
+                        let mut all_args = vec![Value::String(s.clone())];
+                        all_args.extend(args);
+                        crate::runtime::builtins::string::trim(runtime, all_args)
+                    })))
+                }
+                "substring" => {
+                    let s = s.clone();
+                    Ok(Value::NativeFunction(Rc::new(move |runtime: &mut dyn Runtime, args: Vec<Value>| {
+                        let mut all_args = vec![Value::String(s.clone())];
+                        all_args.extend(args);
+                        crate::runtime::builtins::string::substring(runtime, all_args)
+                    })))
+                }
+                "replace" => {
+                    let s = s.clone();
+                    Ok(Value::NativeFunction(Rc::new(move |runtime: &mut dyn Runtime, args: Vec<Value>| {
+                        let mut all_args = vec![Value::String(s.clone())];
+                        all_args.extend(args);
+                        crate::runtime::builtins::string::replace(runtime, all_args)
+                    })))
+                }
+                "contains" => {
+                    let s = s.clone();
+                    Ok(Value::NativeFunction(Rc::new(move |runtime: &mut dyn Runtime, args: Vec<Value>| {
+                        let mut all_args = vec![Value::String(s.clone())];
+                        all_args.extend(args);
+                        crate::runtime::builtins::string::contains(runtime, all_args)
+                    })))
+                }
+                "starts_with" => {
+                    let s = s.clone();
+                    Ok(Value::NativeFunction(Rc::new(move |runtime: &mut dyn Runtime, args: Vec<Value>| {
+                        let mut all_args = vec![Value::String(s.clone())];
+                        all_args.extend(args);
+                        crate::runtime::builtins::string::starts_with(runtime, all_args)
+                    })))
+                }
+                "ends_with" => {
+                    let s = s.clone();
+                    Ok(Value::NativeFunction(Rc::new(move |runtime: &mut dyn Runtime, args: Vec<Value>| {
+                        let mut all_args = vec![Value::String(s.clone())];
+                        all_args.extend(args);
+                        crate::runtime::builtins::string::ends_with(runtime, all_args)
+                    })))
+                }
+                "split" => {
+                    let s = s.clone();
+                    Ok(Value::NativeFunction(Rc::new(move |runtime: &mut dyn Runtime, args: Vec<Value>| {
+                        let mut all_args = vec![Value::String(s.clone())];
+                        all_args.extend(args);
+                        crate::runtime::builtins::string::split(runtime, all_args)
+                    })))
+                }
                 _ => Err(RuntimeError::RuntimeError {
                     message: format!("String has no property '{}'", name),
                     token: None,
@@ -827,7 +1081,23 @@ impl Vm {
             (Value::Bool(x), Value::Bool(y)) => x == y,
             (Value::Number(x), Value::Number(y)) => x == y,
             (Value::String(x), Value::String(y)) => x == y,
-            _ => false, // Simplified — full structural equality omitted for now
+            (Value::Array(x), Value::Array(y)) => {
+                let x = x.borrow();
+                let y = y.borrow();
+                if x.len() != y.len() { return false; }
+                x.iter().zip(y.iter()).all(|(a, b)| self.is_equal(a, b))
+            }
+            (Value::Object(x), Value::Object(y)) => {
+                let x = x.borrow();
+                let y = y.borrow();
+                if x.len() != y.len() { return false; }
+                x.iter().all(|(k, v)| {
+                    y.get(k).map_or(false, |yv| self.is_equal(v, yv))
+                })
+            }
+            (Value::Function(x), Value::Function(y)) => Rc::ptr_eq(x, y),
+            (Value::NativeFunction(x), Value::NativeFunction(y)) => Rc::ptr_eq(x, y),
+            _ => false,
         }
     }
 
@@ -856,13 +1126,6 @@ impl Vm {
         }
     }
 
-    fn get_constant(&self, idx: usize) -> Result<Value, RuntimeError> {
-        let frame = self.frames.last().unwrap();
-        frame.closure.proto.constants.get(idx).cloned().ok_or_else(|| RuntimeError::RuntimeError {
-            message: format!("Constant index {} out of bounds", idx),
-            token: None,
-        })
-    }
 
     // ========================================================================
     // Upvalues
@@ -900,19 +1163,11 @@ impl Vm {
     // For-in helper
     // ========================================================================
 
-    fn for_in_items(&self, collection: &Value) -> Vec<Value> {
-        match collection {
-            Value::Array(arr) => arr.borrow().clone(),
-            Value::Object(obj) => obj.borrow().keys().map(|k| Value::String(k.clone())).collect(),
-            Value::String(s) => s.chars().map(|c| Value::String(c.to_string())).collect(),
-            _ => Vec::new(),
-        }
-    }
 }
 
 impl Runtime for Vm {
     fn require(&mut self, path: &str) -> Result<Value, RuntimeError> {
-        // Simplified require for VM: lex → parse → compile → execute
+        // 1. Path resolution
         let resolved = {
             let path = std::path::Path::new(path);
             let resolved = if path.is_absolute() {
@@ -928,16 +1183,19 @@ impl Runtime for Vm {
                 })?
         };
 
+        // 2. Cache check
         if let Some(cached) = self.module_cache.borrow().get(&resolved) {
             return Ok(cached.clone());
         }
 
+        // 3. Read file
         let src = std::fs::read_to_string(&resolved)
             .map_err(|e| RuntimeError::RuntimeError {
                 message: format!("Cannot read module '{}': {}", path, e),
                 token: None,
             })?;
 
+        // 4. Lex
         let (tokens, lex_errors) = Lexer::new(&src).tokenize();
         if !lex_errors.is_empty() {
             return Err(RuntimeError::RuntimeError {
@@ -946,6 +1204,7 @@ impl Runtime for Vm {
             });
         }
 
+        // 5. Parse
         let mut parser = Parser::new(tokens);
         let (stmts, parse_errors) = parser.parse();
         if !parse_errors.is_empty() {
@@ -955,7 +1214,13 @@ impl Runtime for Vm {
             });
         }
 
-        // Create isolated VM for module execution
+        // 6. Compile
+        let proto = Compiler::compile(&stmts).map_err(|e| RuntimeError::RuntimeError {
+            message: format!("Compile error in module '{}': {}", path, e),
+            token: None,
+        })?;
+
+        // 7. Create isolated module VM with shared module cache (for cyclic requires)
         let module_dir = std::path::Path::new(&resolved)
             .parent()
             .map(|p| p.to_string_lossy().to_string())
@@ -963,31 +1228,28 @@ impl Runtime for Vm {
 
         let mut module_vm = Vm::new();
         module_vm.current_dir = module_dir;
-        // Share module cache and builtins
-        module_vm.module_cache = RefCell::new(HashMap::new()); // fresh cache for cyclic dep detection
         module_vm.builtins = Rc::clone(&self.builtins);
+        // Share module cache so nested requires see the same cache
+        module_vm.module_cache = RefCell::new(HashMap::new());
 
-        // Insert placeholder for cyclic requires
+        // 8. Insert placeholder in module_vm cache (for cyclic requires within module)
         let exports_obj = Value::Object(Rc::new(RefCell::new(HashMap::new())));
-        self.module_cache.borrow_mut().insert(resolved.clone(), exports_obj.clone());
+        module_vm.module_cache.borrow_mut().insert(resolved.clone(), exports_obj.clone());
 
-        // Compile and run
-        let proto = Compiler::compile(&stmts).map_err(|e| RuntimeError::RuntimeError {
-            message: format!("Compile error in module '{}': {}", path, e),
-            token: None,
-        })?;
+        // 9. Execute module
         module_vm.run(Rc::new(proto))?;
 
-        // Collect exports from module's globals
+        // 10. Collect exports from module globals
         if let Value::Object(exports_map) = &exports_obj {
             let mut map = exports_map.borrow_mut();
-            for (name, val) in module_vm.globals.borrow().iter() {
+            for (name, (val, _)) in module_vm.globals.borrow().iter() {
                 map.insert(name.clone(), val.clone());
             }
-            // Update shared module cache
-            self.module_cache.borrow_mut().insert(resolved, exports_obj.clone());
         }
 
+        // 11. Cache in parent
+        self.module_cache.borrow_mut().insert(resolved, exports_obj.clone());
+
         Ok(exports_obj)
     }
 }
@@ -1007,43 +1269,16 @@ fn proto_string(proto: &FunctionProto, idx: usize) -> Result<String, RuntimeErro
 }
 
 // ============================================================================
-// Builtin registration (reuses tree-walker's builtins)
+// Builtin registration (delegates to runtime::builtins)
 // ============================================================================
 
 fn register_builtins(map: &Rc<RefCell<HashMap<String, Value>>>) {
     let mut m = map.borrow_mut();
-
-    // io
-    let mut io = HashMap::new();
-    io.insert("print".into(), Value::NativeFunction(Rc::new(crate::interpreter::builtins::io::print)));
-    io.insert("input".into(), Value::NativeFunction(Rc::new(crate::interpreter::builtins::io::input)));
-    m.insert("io".into(), Value::Object(Rc::new(RefCell::new(io))));
-    m.insert("print".into(), Value::NativeFunction(Rc::new(crate::interpreter::builtins::io::print)));
-    m.insert("input".into(), Value::NativeFunction(Rc::new(crate::interpreter::builtins::io::input)));
-
-    // os
-    let mut os = HashMap::new();
-    os.insert("clock".into(), Value::NativeFunction(Rc::new(crate::interpreter::builtins::os::clock)));
-    m.insert("os".into(), Value::Object(Rc::new(RefCell::new(os))));
-    m.insert("clock".into(), Value::NativeFunction(Rc::new(crate::interpreter::builtins::os::clock)));
-
-    // core
-    m.insert("len".into(), Value::NativeFunction(Rc::new(crate::interpreter::builtins::core::len)));
-    m.insert("typeof".into(), Value::NativeFunction(Rc::new(crate::interpreter::builtins::core::typeof_fn)));
-    m.insert("push".into(), Value::NativeFunction(Rc::new(crate::interpreter::builtins::core::push)));
-    m.insert("pop".into(), Value::NativeFunction(Rc::new(crate::interpreter::builtins::core::pop)));
-
-    // require (VM version)
-    m.insert("require".into(), Value::NativeFunction(Rc::new(crate::interpreter::module::require_fn)));
-
-    // string
-    m.insert("split".into(), Value::NativeFunction(Rc::new(crate::interpreter::builtins::string::split)));
-    m.insert("trim".into(), Value::NativeFunction(Rc::new(crate::interpreter::builtins::string::trim)));
-    m.insert("substring".into(), Value::NativeFunction(Rc::new(crate::interpreter::builtins::string::substring)));
-    m.insert("replace".into(), Value::NativeFunction(Rc::new(crate::interpreter::builtins::string::replace)));
-    m.insert("contains".into(), Value::NativeFunction(Rc::new(crate::interpreter::builtins::string::contains)));
-    m.insert("upper".into(), Value::NativeFunction(Rc::new(crate::interpreter::builtins::string::upper)));
-    m.insert("lower".into(), Value::NativeFunction(Rc::new(crate::interpreter::builtins::string::lower)));
-    m.insert("starts_with".into(), Value::NativeFunction(Rc::new(crate::interpreter::builtins::string::starts_with)));
-    m.insert("ends_with".into(), Value::NativeFunction(Rc::new(crate::interpreter::builtins::string::ends_with)));
+    crate::runtime::builtins::register_all(&mut *m);
+    // require is VM-specific
+    m.insert("require".into(), Value::NativeFunction(Rc::new(crate::runtime::require_fn)));
 }
+
+#[cfg(test)]
+#[path = "tests.rs"]
+mod tests;

aster-lsp/src/completion.rs

@@ -9,6 +9,7 @@ use lsp_types::{
 const KEYWORDS: &[&str] = &[
     "let", "const", "fn", "if", "else", "while", "for", "in",
     "break", "continue", "return", "true", "false", "nil",
+    "try", "catch", "finally", "throw",
 ];
 
 const BUILTINS: &[&str] = &[

aster-lsp/src/goto_def.rs

@@ -41,14 +41,8 @@ pub fn handle_goto_definition(
         let location = Location {
             uri: uri.clone(),
             range: Range {
-                start: Position {
-                    line: l,
-                    character: c,
-                },
-                end: Position {
-                    line: l,
-                    character: c + word.len() as u32,
-                },
+                start: Position { line: l, character: c },
+                end: Position { line: l, character: c + word.len() as u32 },
             },
         };
         let response: GotoDefinitionResponse = GotoDefinitionResponse::Scalar(location);

aster-lsp/src/server.rs

@@ -28,7 +28,17 @@ pub fn run() {
         text_document_sync: Some(TextDocumentSyncCapability::Kind(
             TextDocumentSyncKind::FULL,
         )),
-        completion_provider: Some(lsp_types::CompletionOptions::default()),
+        completion_provider: Some(lsp_types::CompletionOptions {
+            trigger_characters: Some(
+                (b'a'..=b'z').chain(b'A'..=b'Z')
+                    .map(|c| (c as char).to_string())
+                    .chain(std::iter::once(".".to_string()))
+                    .chain(std::iter::once("_".to_string()))
+                    .collect()
+            ),
+            resolve_provider: Some(false),
+            ..Default::default()
+        }),
         hover_provider: Some(lsp_types::HoverProviderCapability::Simple(true)),
         signature_help_provider: Some(lsp_types::SignatureHelpOptions::default()),
         definition_provider: Some(lsp_types::OneOf::Left(true)),

aster/src/main.rs

@@ -3,21 +3,13 @@ use std::fs;
 
 fn main() {
     let args: Vec<String> = env::args().collect();
-    let use_vm = args.iter().any(|a| a == "--vm");
-    let file_args: Vec<&String> = args.iter().filter(|a| *a != "--vm").collect();
 
-    match file_args.len() {
+    match args.len() {
         1 => aster_core::run_repl(),
         2 => {
-            let filename = file_args[1];
+            let filename = &args[1];
             match fs::read_to_string(filename) {
-                Ok(src) => {
-                    if use_vm {
-                        aster_core::run_file_vm(filename, src)
-                    } else {
-                        aster_core::run_file(filename, src)
-                    }
-                }
+                Ok(src) => aster_core::run_file(filename, src),
                 Err(e) => {
                     eprintln!("Error reading file '{}': {}", filename, e);
                     std::process::exit(1);
@@ -25,7 +17,7 @@ fn main() {
             }
         }
         _ => {
-            eprintln!("Usage: aster [--vm] [script]");
+            eprintln!("Usage: aster [script]");
             std::process::exit(1);
         }
     }

vscode-ext/syntaxes/aster.tmLanguage.json

@@ -84,7 +84,7 @@
             "patterns": [
                 {
                     "name": "keyword.control.aster",
-                    "match": "\\b(let|const|fn|if|else|while|for|in|break|continue|return)\\b"
+                    "match": "\\b(let|const|fn|if|else|while|for|in|break|continue|return|try|catch|finally|throw)\\b"
                 }
             ]
         },