feat: 更新错误处理机制，增强词法分析器和解析器的错误报告功能

src/error/error.rs

@@ -2,13 +2,35 @@ use crate::lexer::Token;
 
 #[derive(Debug)]
 pub enum RuntimeError {
+    LexError { message: String, line: usize, column: usize },
     ParseError { message: String, token: Token },
     RuntimeError { message: String, token: Option<Token> },
 }
 
+impl RuntimeError {
+    pub fn lex(message: impl Into<String>, line: usize, column: usize) -> Self {
+        RuntimeError::LexError {
+            message: message.into(),
+            line,
+            column,
+        }
+    }
+
+    pub fn parse(message: impl Into<String>, token: Token) -> Self {
+        RuntimeError::ParseError {
+            message: message.into(),
+            token,
+        }
+    }
+
+}
+
 impl std::fmt::Display for RuntimeError {
     fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         match self {
+            RuntimeError::LexError { message, line, column } => {
+                write!(f, "[Lex Error] {} at line {}, column {}", message, line, column)
+            }
             RuntimeError::ParseError { message, token } => {
                 write!(f, "[Parse Error] {} at line {}, column {}", message, token.line, token.column)
             }

src/lexer/lexer.rs

@@ -1,6 +1,7 @@
 // src/lexer/lexer.rs
 
 use super::{Token, TokenKind};
+use crate::error::RuntimeError;
 
 pub struct Lexer {
     src: Vec<char>,
@@ -19,11 +20,12 @@ impl Lexer {
         }
     }
 
-    pub fn tokenize(mut self) -> Vec<Token> {
+    pub fn tokenize(mut self) -> (Vec<Token>, Vec<RuntimeError>) {
         let mut tokens = Vec::new();
+        let mut errors = Vec::new();
 
         while !self.is_at_end() {
-            if let Some(token) = self.next_token() {
+            if let Some(token) = self.next_token(&mut errors) {
                 tokens.push(token);
             }
         }
@@ -34,10 +36,10 @@ impl Lexer {
             column: self.column,
         });
 
-        tokens
+        (tokens, errors)
     }
 
-    fn next_token(&mut self) -> Option<Token> {
+    fn next_token(&mut self, errors: &mut Vec<RuntimeError>) -> Option<Token> {
         self.skip_whitespace();
 
         if self.is_at_end() {
@@ -140,7 +142,8 @@ impl Lexer {
                 if self.match_char('&') {
                     TokenKind::AndAnd
                 } else {
-                    panic!("Unexpected '&' at {}:{}", line, column);
+                    errors.push(RuntimeError::lex("Unexpected '&'. Did you mean '&&'?", line, column));
+                    return None;
                 }
             }
 
@@ -148,11 +151,12 @@ impl Lexer {
                 if self.match_char('|') {
                     TokenKind::OrOr
                 } else {
-                    panic!("Unexpected '|' at {}:{}", line, column);
+                    errors.push(RuntimeError::lex("Unexpected '|'. Did you mean '||'?", line, column));
+                    return None;
                 }
             }
 
-            '"' => return Some(self.string_literal(line, column)),
+            '"' => return self.string_literal(line, column, errors),
 
             c if c.is_ascii_digit() => {
                 return Some(self.number_literal(c, line, column));
@@ -163,7 +167,12 @@ impl Lexer {
             }
 
             _ => {
-                panic!("Unexpected character '{}' at {}:{}", c, line, column);
+                errors.push(RuntimeError::lex(
+                    format!("Unexpected character '{}'", c),
+                    line,
+                    column,
+                ));
+                return None;
             }
         };
 
@@ -215,7 +224,12 @@ impl Lexer {
         self.current >= self.src.len()
     }
 
-    fn string_literal(&mut self, line: usize, column: usize) -> Token {
+    fn string_literal(
+        &mut self,
+        line: usize,
+        column: usize,
+        errors: &mut Vec<RuntimeError>,
+    ) -> Option<Token> {
         let mut value = String::new();
 
         while !self.is_at_end() && self.peek() != '"' {
@@ -223,16 +237,17 @@ impl Lexer {
         }
 
         if self.is_at_end() {
-            panic!("Unterminated string at {}:{}", line, column);
+            errors.push(RuntimeError::lex("Unterminated string literal", line, column));
+            return None;
         }
 
         self.advance(); // consume closing "
 
-        Token {
+        Some(Token {
             kind: TokenKind::String(value),
             line,
             column,
-        }
+        })
     }
 
     fn number_literal(&mut self, first: char, line: usize, column: usize) -> Token {

src/main.rs

@@ -7,21 +7,37 @@ mod error;
 use lexer::Lexer;
 use parser::Parser;
 use interpreter::Interpreter;
+use error::RuntimeError;
 use std::env;
 use std::fs;
 use std::io::Write;
 use std::io::stdin;
 use std::io::stdout;
 
+fn print_errors(errors: &[RuntimeError]) {
+    for err in errors {
+        eprintln!("{}", err);
+    }
+}
+
 fn run_file(src: String) {
-    let tokens = Lexer::new(&src).tokenize();
+    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 = parser.parse();
+    let (stmts, parse_errors) = parser.parse();
+    if !parse_errors.is_empty() {
+        print_errors(&parse_errors);
+        std::process::exit(65);
+    }
 
     let mut interpreter = Interpreter::new();
     if let Err(e) = interpreter.interpret(stmts) {
         eprintln!("Error: {}", e);
-        std::process::exit(1);
+        std::process::exit(70);
     }
 }
 
@@ -61,9 +77,18 @@ fn run_repl() {
             _ => {}
         }
 
-        let tokens = Lexer::new(line).tokenize();
+        let (tokens, lex_errors) = Lexer::new(line).tokenize();
+        if !lex_errors.is_empty() {
+            print_errors(&lex_errors);
+            continue;
+        }
+
         let mut parser = Parser::new(tokens);
-        let stmts = parser.parse();
+        let (stmts, parse_errors) = parser.parse();
+        if !parse_errors.is_empty() {
+            print_errors(&parse_errors);
+            continue;
+        }
 
         if let Err(e) = interpreter.interpret(stmts) {
             eprintln!("Error: {}", e);

src/parser/parser.rs

@@ -12,17 +12,24 @@ impl Parser {
         Self { tokens, current: 0 }
     }
 
-    pub fn parse(&mut self) -> Vec<Stmt> {
+    pub fn parse(&mut self) -> (Vec<Stmt>, Vec<RuntimeError>) {
         let mut statements = Vec::new();
+        let mut errors = Vec::new();
 
         while !self.is_at_end() {
-            statements.push(self.declaration());
+            match self.declaration() {
+                Ok(stmt) => statements.push(stmt),
+                Err(err) => {
+                    errors.push(err);
+                    self.synchronize();
+                }
+            }
         }
 
-        statements
+        (statements, errors)
     }
 
-    fn declaration(&mut self) -> Stmt {
+    fn declaration(&mut self) -> Result<Stmt, RuntimeError> {
         if self.match_kind(&[TokenKind::Let]) {
             self.let_declaration()
         } else if self.match_kind(&[TokenKind::Fn]) {
@@ -32,7 +39,7 @@ impl Parser {
         }
     }
 
-    fn statement(&mut self) -> Stmt {
+    fn statement(&mut self) -> Result<Stmt, RuntimeError> {
         if self.match_kind(&[TokenKind::If]) {
             self.if_statement()
         } else if self.match_kind(&[TokenKind::While]) {
@@ -46,161 +53,161 @@ impl Parser {
         } else if self.match_kind(&[TokenKind::Return]) {
             self.return_statement()
         } else if self.match_kind(&[TokenKind::LeftBrace]) {
-            Stmt::Block(self.block())
+            Ok(Stmt::Block(self.block()?))
         } else {
             self.expression_statement()
         }
     }
 
-    fn let_declaration(&mut self) -> Stmt {
-        let name = self.consume_ident("Expected variable name.").unwrap();
-        self.consume(TokenKind::Equal, "Expected '=' after variable name.").unwrap();
-        let initializer = self.expression();
+    fn let_declaration(&mut self) -> Result<Stmt, RuntimeError> {
+        let name = self.consume_ident("Expected variable name.")?;
+        self.consume(TokenKind::Equal, "Expected '=' after variable name.")?;
+        let initializer = self.expression()?;
         self.match_kind(&[TokenKind::Semicolon]); // 分号可选
 
-        Stmt::Let { name, initializer }
+        Ok(Stmt::Let { name, initializer })
     }
 
-    fn fn_declaration(&mut self) -> Stmt {
-        let name = self.consume_ident("Expected function name.").unwrap();
-        self.consume(TokenKind::LeftParen, "Expected '(' after function name.").unwrap();
+    fn fn_declaration(&mut self) -> Result<Stmt, RuntimeError> {
+        let name = self.consume_ident("Expected function name.")?;
+        self.consume(TokenKind::LeftParen, "Expected '(' after function name.")?;
 
         let mut params = Vec::new();
         if !self.check(&TokenKind::RightParen) {
             loop {
-                params.push(self.consume_ident("Expected parameter name.").unwrap());
+                params.push(self.consume_ident("Expected parameter name.")?);
                 if !self.match_kind(&[TokenKind::Comma]) {
                     break;
                 }
             }
         }
 
-        self.consume(TokenKind::RightParen, "Expected ')' after parameters.").unwrap();
-        self.consume(TokenKind::LeftBrace, "Expected '{' before function body.").unwrap();
-        let body = self.block();
+        self.consume(TokenKind::RightParen, "Expected ')' after parameters.")?;
+        self.consume(TokenKind::LeftBrace, "Expected '{' before function body.")?;
+        let body = self.block()?;
 
-        Stmt::Function { name, params, body }
+        Ok(Stmt::Function { name, params, body })
     }
 
-    fn lambda_expr(&mut self) -> Expr {
-        self.consume(TokenKind::LeftParen, "Expected '(' after 'fn'.").unwrap();
+    fn lambda_expr(&mut self) -> Result<Expr, RuntimeError> {
+        self.consume(TokenKind::LeftParen, "Expected '(' after 'fn'.")?;
         let mut params = Vec::new();
         if !self.check(&TokenKind::RightParen) {
             loop {
-                params.push(self.consume_ident("Expected parameter name.").unwrap());
+                params.push(self.consume_ident("Expected parameter name.")?);
                 if !self.match_kind(&[TokenKind::Comma]) {
                     break;
                 }
             }
         }
-        self.consume(TokenKind::RightParen, "Expected ')' after parameters.").unwrap();
-        self.consume(TokenKind::LeftBrace, "Expected '{' before function body.").unwrap();
-        let body = self.block();
-        Expr::Lambda { params, body }
+        self.consume(TokenKind::RightParen, "Expected ')' after parameters.")?;
+        self.consume(TokenKind::LeftBrace, "Expected '{' before function body.")?;
+        let body = self.block()?;
+        Ok(Expr::Lambda { params, body })
     }
 
-    fn if_statement(&mut self) -> Stmt {
-        self.consume(TokenKind::LeftParen, "Expected '(' after 'if'.").unwrap();
-        let condition = self.expression();
-        self.consume(TokenKind::RightParen, "Expected ')' after condition.").unwrap();
+    fn if_statement(&mut self) -> Result<Stmt, RuntimeError> {
+        self.consume(TokenKind::LeftParen, "Expected '(' after 'if'.")?;
+        let condition = self.expression()?;
+        self.consume(TokenKind::RightParen, "Expected ')' after condition.")?;
 
-        let then_branch = Box::new(self.statement());
+        let then_branch = Box::new(self.statement()?);
         let else_branch = if self.match_kind(&[TokenKind::Else]) {
-            Some(Box::new(self.statement()))
+            Some(Box::new(self.statement()?))
         } else {
             None
         };
 
-        Stmt::If { condition, then_branch, else_branch }
+        Ok(Stmt::If { condition, then_branch, else_branch })
     }
 
-    fn while_statement(&mut self) -> Stmt {
-        self.consume(TokenKind::LeftParen, "Expected '(' after 'while'.").unwrap();
-        let condition = self.expression();
-        self.consume(TokenKind::RightParen, "Expected ')' after condition.").unwrap();
+    fn while_statement(&mut self) -> Result<Stmt, RuntimeError> {
+        self.consume(TokenKind::LeftParen, "Expected '(' after 'while'.")?;
+        let condition = self.expression()?;
+        self.consume(TokenKind::RightParen, "Expected ')' after condition.")?;
 
-        let body = Box::new(self.statement());
-        Stmt::While { condition, body }
+        let body = Box::new(self.statement()?);
+        Ok(Stmt::While { condition, body })
     }
 
-    fn for_statement(&mut self) -> Stmt {
-        self.consume(TokenKind::LeftParen, "Expected '(' after 'for'.").unwrap();
+    fn for_statement(&mut self) -> Result<Stmt, RuntimeError> {
+        self.consume(TokenKind::LeftParen, "Expected '(' after 'for'.")?;
         let initializer = if self.match_kind(&[TokenKind::Semicolon]) {
             None
         } else if self.match_kind(&[TokenKind::Let]) {
-            Some(self.let_declaration())
+            Some(self.let_declaration()?)
         } else {
-            Some(self.expression_statement())
+            Some(self.expression_statement()?)
         };
 
         let condition = if !self.check(&TokenKind::Semicolon) {
-            Some(self.expression())
+            Some(self.expression()?)
         } else {
             None
         };
 
-        self.consume(TokenKind::Semicolon, "Expected ';' after loop condition.").unwrap();
+        self.consume(TokenKind::Semicolon, "Expected ';' after loop condition.")?;
         let step = if !self.check(&TokenKind::RightParen) {
-            Some(self.expression())
+            Some(self.expression()?)
         } else {
             None
         };
 
-        self.consume(TokenKind::RightParen, "Expected ')' after for clauses.").unwrap();
-        let body = Box::new(self.statement());
+        self.consume(TokenKind::RightParen, "Expected ')' after for clauses.")?;
+        let body = Box::new(self.statement()?);
 
-        Stmt::For {
+        Ok(Stmt::For {
             initializer: initializer.map(Box::new),
             condition,
             step,
             body
-        }
+        })
     }
 
-    fn break_statement(&mut self) -> Stmt {
+    fn break_statement(&mut self) -> Result<Stmt, RuntimeError> {
         self.match_kind(&[TokenKind::Semicolon]); // 分号可选
-        Stmt::Break
+        Ok(Stmt::Break)
     }
 
-    fn continue_statement(&mut self) -> Stmt {
+    fn continue_statement(&mut self) -> Result<Stmt, RuntimeError> {
         self.match_kind(&[TokenKind::Semicolon]); // 分号可选
-        Stmt::Continue
+        Ok(Stmt::Continue)
     }
 
-    fn return_statement(&mut self) -> Stmt {
+    fn return_statement(&mut self) -> Result<Stmt, RuntimeError> {
         let value = if !self.check(&TokenKind::Semicolon) && !self.check(&TokenKind::RightBrace) {
-            Some(self.expression())
+            Some(self.expression()?)
         } else {
             None
         };
 
         self.match_kind(&[TokenKind::Semicolon]); // 分号可选
-        Stmt::Return(value)
+        Ok(Stmt::Return(value))
     }
 
-    fn block(&mut self) -> Vec<Stmt> {
+    fn block(&mut self) -> Result<Vec<Stmt>, RuntimeError> {
         let mut statements = Vec::new();
 
         while !self.check(&TokenKind::RightBrace) && !self.is_at_end() {
-            statements.push(self.declaration());
+            statements.push(self.declaration()?);
         }
 
-        self.consume(TokenKind::RightBrace, "Expected '}' after block.").unwrap();
-        statements
+        self.consume(TokenKind::RightBrace, "Expected '}' after block.")?;
+        Ok(statements)
     }
 
-    fn expression_statement(&mut self) -> Stmt {
-        let expr = self.expression();
+    fn expression_statement(&mut self) -> Result<Stmt, RuntimeError> {
+        let expr = self.expression()?;
         self.match_kind(&[TokenKind::Semicolon]); // 分号可选
-        Stmt::ExprStmt(expr)
+        Ok(Stmt::ExprStmt(expr))
     }
 
-    fn expression(&mut self) -> Expr {
+    fn expression(&mut self) -> Result<Expr, RuntimeError> {
         self.assignment()
     }
 
-    fn assignment(&mut self) -> Expr {
-        let expr = self.logical_or();
+    fn assignment(&mut self) -> Result<Expr, RuntimeError> {
+        let expr = self.logical_or()?;
 
         let op = if self.match_kind(&[TokenKind::Equal]) {
             Some(AssignOp::Equal)
@@ -219,23 +226,23 @@ impl Parser {
         };
 
         if let Some(op) = op {
-            let value = self.assignment();
+            let value = self.assignment()?;
             return match expr {
-                Expr::Variable(name) => Expr::Assign { name, op, value: Box::new(value) },
-                Expr::Get { object, name } => Expr::Set { object, name, op, value: Box::new(value) },
-                Expr::IndexGet { array, index } => Expr::IndexSet { array, index, op, value: Box::new(value) },
-                _ => panic!("Invalid assignment target."),
+                Expr::Variable(name) => Ok(Expr::Assign { name, op, value: Box::new(value) }),
+                Expr::Get { object, name } => Ok(Expr::Set { object, name, op, value: Box::new(value) }),
+                Expr::IndexGet { array, index } => Ok(Expr::IndexSet { array, index, op, value: Box::new(value) }),
+                _ => Err(RuntimeError::parse("Invalid assignment target.", self.previous().clone())),
             };
         }
 
-        expr
+        Ok(expr)
     }
 
-    fn logical_or(&mut self) -> Expr {
-        let mut expr = self.logical_and();
+    fn logical_or(&mut self) -> Result<Expr, RuntimeError> {
+        let mut expr = self.logical_and()?;
 
         while self.match_kind(&[TokenKind::OrOr]) {
-            let right = self.logical_and();
+            let right = self.logical_and()?;
             expr = Expr::Logical {
                 left: Box::new(expr),
                 op: LogicalOp::Or,
@@ -243,14 +250,14 @@ impl Parser {
             };
         }
 
-        expr
+        Ok(expr)
     }
 
-    fn logical_and(&mut self) -> Expr {
-        let mut expr = self.equality();
+    fn logical_and(&mut self) -> Result<Expr, RuntimeError> {
+        let mut expr = self.equality()?;
 
         while self.match_kind(&[TokenKind::AndAnd]) {
-            let right = self.equality();
+            let right = self.equality()?;
             expr = Expr::Logical {
                 left: Box::new(expr),
                 op: LogicalOp::And,
@@ -258,11 +265,11 @@ impl Parser {
             };
         }
 
-        expr
+        Ok(expr)
     }
 
-    fn equality(&mut self) -> Expr {
-        let mut expr = self.comparison();
+    fn equality(&mut self) -> Result<Expr, RuntimeError> {
+        let mut expr = self.comparison()?;
 
         while self.match_kind(&[TokenKind::EqualEqual, TokenKind::BangEqual]) {
             let op = match self.previous().kind {
@@ -270,7 +277,7 @@ impl Parser {
                 TokenKind::BangEqual => BinaryOp::NotEqual,
                 _ => unreachable!(),
             };
-            let right = self.comparison();
+            let right = self.comparison()?;
             expr = Expr::Binary {
                 left: Box::new(expr),
                 op,
@@ -278,11 +285,11 @@ impl Parser {
             };
         }
 
-        expr
+        Ok(expr)
     }
 
-    fn comparison(&mut self) -> Expr {
-        let mut expr = self.term();
+    fn comparison(&mut self) -> Result<Expr, RuntimeError> {
+        let mut expr = self.term()?;
 
         while self.match_kind(&[TokenKind::Greater, TokenKind::GreaterEqual, TokenKind::Less, TokenKind::LessEqual]) {
             let op = match self.previous().kind {
@@ -292,7 +299,7 @@ impl Parser {
                 TokenKind::LessEqual => BinaryOp::LessEqual,
                 _ => unreachable!(),
             };
-            let right = self.term();
+            let right = self.term()?;
             expr = Expr::Binary {
                 left: Box::new(expr),
                 op,
@@ -300,11 +307,11 @@ impl Parser {
             };
         }
 
-        expr
+        Ok(expr)
     }
 
-    fn term(&mut self) -> Expr {
-        let mut expr = self.factor();
+    fn term(&mut self) -> Result<Expr, RuntimeError> {
+        let mut expr = self.factor()?;
 
         while self.match_kind(&[TokenKind::Plus, TokenKind::Minus]) {
             let op = match self.previous().kind {
@@ -312,7 +319,7 @@ impl Parser {
                 TokenKind::Minus => BinaryOp::Sub,
                 _ => unreachable!(),
             };
-            let right = self.factor();
+            let right = self.factor()?;
             expr = Expr::Binary {
                 left: Box::new(expr),
                 op,
@@ -320,11 +327,11 @@ impl Parser {
             };
         }
 
-        expr
+        Ok(expr)
     }
 
-    fn factor(&mut self) -> Expr {
-        let mut expr = self.unary();
+    fn factor(&mut self) -> Result<Expr, RuntimeError> {
+        let mut expr = self.unary()?;
 
         while self.match_kind(&[TokenKind::Star, TokenKind::Slash, TokenKind::Percent]) {
             let op = match self.previous().kind {
@@ -333,7 +340,7 @@ impl Parser {
                 TokenKind::Percent => BinaryOp::Mod,
                 _ => unreachable!(),
             };
-            let right = self.unary();
+            let right = self.unary()?;
             expr = Expr::Binary {
                 left: Box::new(expr),
                 op,
@@ -341,54 +348,54 @@ impl Parser {
             };
         }
 
-        expr
+        Ok(expr)
     }
 
-    fn unary(&mut self) -> Expr {
+    fn unary(&mut self) -> Result<Expr, RuntimeError> {
         if self.match_kind(&[TokenKind::Bang, TokenKind::Minus]) {
             let op = match self.previous().kind {
                 TokenKind::Bang => UnaryOp::Not,
                 TokenKind::Minus => UnaryOp::Negate,
                 _ => unreachable!(),
             };
-            let right = self.unary();
-            return Expr::Unary {
+            let right = self.unary()?;
+            return Ok(Expr::Unary {
                 op,
                 right: Box::new(right),
-            };
+            });
         }
 
         self.call()
     }
 
-    fn call(&mut self) -> Expr {
-        let mut expr = self.primary();
+    fn call(&mut self) -> Result<Expr, RuntimeError> {
+        let mut expr = self.primary()?;
 
         loop {
             if self.match_kind(&[TokenKind::LeftParen]) {
                 let mut arguments = Vec::new();
                 if !self.check(&TokenKind::RightParen) {
                     loop {
-                        arguments.push(self.expression());
+                        arguments.push(self.expression()?);
                         if !self.match_kind(&[TokenKind::Comma]) {
                             break;
                         }
                     }
                 }
-                self.consume(TokenKind::RightParen, "Expected ')' after arguments.").unwrap();
+                self.consume(TokenKind::RightParen, "Expected ')' after arguments.")?;
                 expr = Expr::Call {
                     callee: Box::new(expr),
                     arguments,
                 };
             } else if self.match_kind(&[TokenKind::Dot]) {
-                let name = self.consume_ident("Expected property name after '.'.").unwrap();
+                let name = self.consume_ident("Expected property name after '.'.")?;
                 expr = Expr::Get {
                     object: Box::new(expr),
                     name,
                 };
             } else if self.match_kind(&[TokenKind::LeftBracket]) {
-                let index = self.expression();
-                self.consume(TokenKind::RightBracket, "Expected ']' after index.").unwrap();
+                let index = self.expression()?;
+                self.consume(TokenKind::RightBracket, "Expected ']' after index.")?;
                 expr = Expr::IndexGet {
                     array: Box::new(expr),
                     index: Box::new(index),
@@ -398,39 +405,39 @@ impl Parser {
             }
         }
 
-        expr
+        Ok(expr)
     }
 
-    fn primary(&mut self) -> Expr {
+    fn primary(&mut self) -> Result<Expr, RuntimeError> {
         // 布尔值
         if self.match_kind(&[TokenKind::True]) {
-            return Expr::Literal(Literal::Bool(true));
+            return Ok(Expr::Literal(Literal::Bool(true)));
         }
         if self.match_kind(&[TokenKind::False]) {
-            return Expr::Literal(Literal::Bool(false));
+            return Ok(Expr::Literal(Literal::Bool(false)));
         }
         if self.match_kind(&[TokenKind::Nil]) {
-            return Expr::Literal(Literal::Nil);
+            return Ok(Expr::Literal(Literal::Nil));
         }
 
         // 数字
         if let TokenKind::Number(n) = self.peek().kind {
             self.advance();
-            return Expr::Literal(Literal::Number(n));
+            return Ok(Expr::Literal(Literal::Number(n)));
         }
 
         // 字符串
         if let TokenKind::String(s) = &self.peek().kind {
             let s = s.clone();
             self.advance();
-            return Expr::Literal(Literal::String(s));
+            return Ok(Expr::Literal(Literal::String(s)));
         }
 
         // 标识符（变量）
         if let TokenKind::Identifier(name) = &self.peek().kind {
             let name = name.clone();
             self.advance();
-            return Expr::Variable(name);
+            return Ok(Expr::Variable(name));
         }
 
         // 匿名函数（闭包）: fn(params) { body }
@@ -440,9 +447,9 @@ impl Parser {
 
         // 括号表达式
         if self.match_kind(&[TokenKind::LeftParen]) {
-            let expr = self.expression();
-            self.consume(TokenKind::RightParen, "Expected ')' after expression.").unwrap();
-            return expr;
+            let expr = self.expression()?;
+            self.consume(TokenKind::RightParen, "Expected ')' after expression.")?;
+            return Ok(expr);
         }
 
         if self.match_kind(&[TokenKind::LeftBrace]) {
@@ -453,7 +460,7 @@ impl Parser {
             return self.array_literal();
         }
 
-        panic!("Expected expression at line {}", self.peek().line);
+        Err(RuntimeError::parse("Expected expression.", self.peek().clone()))
     }
 
     fn match_kind(&mut self, kinds: &[TokenKind]) -> bool {
@@ -471,10 +478,7 @@ impl Parser {
             self.advance();
             Ok(())
         } else {
-            Err(RuntimeError::ParseError {
-                message: msg.to_string(),
-                token: self.peek().clone(),
-            })
+            Err(RuntimeError::parse(msg, self.peek().clone()))
         }
     }
 
@@ -485,10 +489,7 @@ impl Parser {
                 self.advance();
                 Ok(name)
             }
-            _ => Err(RuntimeError::ParseError {
-                message: msg.to_string(),
-                token: self.peek().clone(),
-            }),
+            _ => Err(RuntimeError::parse(msg, self.peek().clone())),
         }
     }
 
@@ -519,34 +520,56 @@ impl Parser {
         &self.tokens[self.current - 1]
     }
 
-    fn object_literal(&mut self) -> Expr {
+    fn object_literal(&mut self) -> Result<Expr, RuntimeError> {
         let mut properties = Vec::new();
         if !self.check(&TokenKind::RightBrace) {
             loop {
-                let name = self.consume_ident("Expected property name in object literal").unwrap();
-                self.consume(TokenKind::Colon, "Expected ':' after property name in object literal").unwrap();
-                let value = self.expression();
+                let name = self.consume_ident("Expected property name in object literal")?;
+                self.consume(TokenKind::Colon, "Expected ':' after property name in object literal")?;
+                let value = self.expression()?;
                 properties.push((name, value));
                 if !self.match_kind(&[TokenKind::Comma]) {
                     break;
                 }
             }
         }
-        self.consume(TokenKind::RightBrace, "Expected '}' after object literal").unwrap();
-        Expr::ObjectLiteral { properties }
+        self.consume(TokenKind::RightBrace, "Expected '}' after object literal")?;
+        Ok(Expr::ObjectLiteral { properties })
     }
 
-    fn array_literal(&mut self) -> Expr {
+    fn array_literal(&mut self) -> Result<Expr, RuntimeError> {
         let mut elements = Vec::new();
         if !self.check(&TokenKind::RightBracket) {
             loop {
-                elements.push(self.expression());
+                elements.push(self.expression()?);
                 if !self.match_kind(&[TokenKind::Comma]) {
                     break;
                 }
             }
         }
-        self.consume(TokenKind::RightBracket, "Expected ']' after array literal").unwrap();
-        Expr::ArrayLiteral { elements }
+        self.consume(TokenKind::RightBracket, "Expected ']' after array literal")?;
+        Ok(Expr::ArrayLiteral { elements })
+    }
+
+    fn synchronize(&mut self) {
+        while !self.is_at_end() {
+            if self.current > 0 && matches!(self.previous().kind, TokenKind::Semicolon) {
+                return;
+            }
+
+            match self.peek().kind {
+                TokenKind::Let
+                | TokenKind::Fn
+                | TokenKind::If
+                | TokenKind::While
+                | TokenKind::For
+                | TokenKind::Return
+                | TokenKind::Break
+                | TokenKind::Continue => return,
+                _ => {
+                    self.advance();
+                }
+            }
+        }
     }
 }