feat: break & continue

src/ast.rs

@@ -3,7 +3,7 @@
 use std::io;
 
 use crate::ast_token::{get_token_keyword, Token, get_token_literal};
-use crate::ast_node::{ Expression, NumberLiteral, StringLiteral, Statement, IdentifierLiteral, ExpressionStatement, PropertyAccessExpression, BinaryExpression, ConditionalExpression, CallExpression, Keywords, Parameter, BlockStatement, ReturnStatement, Declaration, PropertyAssignment, ObjectLiteral, ElementAccessExpression, FunctionDeclaration, PostfixUnaryExpression, PrefixUnaryExpression, AssignExpression, GroupExpression, VariableDeclaration, VariableDeclarationStatement, VariableFlag, ClassDeclaration, ClassMethodDeclaration, ArrayLiteral, ComputedPropertyName, IfStatement, ForStatement};
+use crate::ast_node::{ Expression, NumberLiteral, StringLiteral, Statement, IdentifierLiteral, ExpressionStatement, PropertyAccessExpression, BinaryExpression, ConditionalExpression, CallExpression, Keywords, Parameter, BlockStatement, ReturnStatement, Declaration, PropertyAssignment, ObjectLiteral, ElementAccessExpression, FunctionDeclaration, PostfixUnaryExpression, PrefixUnaryExpression, AssignExpression, GroupExpression, VariableDeclaration, VariableDeclarationStatement, VariableFlag, ClassDeclaration, ClassMethodDeclaration, ArrayLiteral, ComputedPropertyName, IfStatement, ForStatement, BreakStatement, ContinueStatement, LabeledStatement};
 use crate::ast_utils::{get_hex_number_value, chars_to_string};
 pub struct AST {
  // 当前字符
@@ -109,6 +109,8 @@ impl AST{
  Token::Var | Token::Let => self.parse_variable_statement(),
  Token::If => self.parse_if_statement(),
  Token::For => self.parse_for_statement(),
+ Token::Break => self.parse_break_statement(),
+ Token::Continue => self.parse_continue_statement(),
  Token::Function => {
  Statement::Function(self.parse_function(true))
  },
@@ -123,8 +125,23 @@ impl AST{
  },
  _ => {
  let expression = self.parse_expression();
+
+ // label:
+ if self.token == Token::Colon {
+ if let Expression::Identifier(identifier) = expression {
+ // TODO: 检测当前的作用域是否已经存在这个 lable，如果存在，则报错
+ // let label = identifier.literal;
+ self.next();
+ let statement = self.parse_statement();
+ return Statement::Label(LabeledStatement {
+ label: identifier,
+ statement: Box::new(statement),
+ });
+ }
+ }
+
  match expression {
- Expression::Unknown => {
+ Expression::Unknown => { 
  Statement::Unknown
  },
  _ => {
@@ -237,6 +254,58 @@ impl AST{
  return Statement::For(statement);
  }
 
+ fn parse_break_statement(&mut self) -> Statement {
+ self.check_token_and_next(Token::Break);
+ let mut semicolon = false;
+ // break;
+ if self.token == Token::Semicolon {
+ self.next();
+ semicolon = true;
+ }
+
+ // for() { break }
+ if semicolon || self.token == Token::RightBrace {
+ /*
+ TODO:
+ if self.scope.in_iteration || self.scope.in_switch {
+
+ } else {
+ // need label, throw error Illegal break statement
+ }
+ */
+ return Statement::Break(BreakStatement {
+ label: None
+ });
+ }
+
+ self.check_token(Token::Identifier);
+ return Statement::Break(BreakStatement {
+ label: Some(IdentifierLiteral { literal: self.literal.clone() })
+ });
+ }
+
+ fn parse_continue_statement(&mut self) -> Statement {
+ self.check_token_and_next(Token::Continue);
+ let mut semicolon = false;
+ // continue;
+ if self.token == Token::Semicolon {
+ self.next();
+ semicolon = true;
+ }
+
+ // for() { continue }
+ if semicolon || self.token == Token::RightBrace {
+ return Statement::Continue(ContinueStatement {
+ label: None
+ });
+ }
+
+ self.check_token(Token::Identifier);
+ return Statement::Continue(ContinueStatement {
+ label: Some(IdentifierLiteral { literal: self.literal.clone() })
+ });
+ }
+
  // 解析 function statement
  fn parse_function(&mut self, variable_lifting: bool) -> FunctionDeclaration {
  // 如果是 function 关键字，则跳过

src/ast_node.rs

@@ -4,16 +4,20 @@ use crate::{ast_token::Token, value::Value, builtins::{object::Object}};
 
 #[derive(Clone)]
 pub enum Statement {
- Var(VariableDeclarationStatement),
- If(IfStatement),
+ // A -> Z
+ Block(BlockStatement),
+ Break(BreakStatement),
+ BuiltinFunction(BuiltinFunction),
+ Class(ClassDeclaration),
+ Continue(ContinueStatement),
+ Expression(ExpressionStatement),
  For(ForStatement),
  Function(FunctionDeclaration),
- Class(ClassDeclaration),
- Block(BlockStatement),
+ If(IfStatement),
+ Label(LabeledStatement),
  Return(ReturnStatement),
- Expression(ExpressionStatement),
- BuiltinFunction(BuiltinFunction),
- Unknown,
+ Unknown, // 未知
+ Var(VariableDeclarationStatement),
 }
 
 impl PartialEq for Statement {
@@ -32,7 +36,25 @@ impl PartialEq for Statement {
 
 impl fmt::Debug for Statement {
  fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
- write!(f, "statement")
+ let mut stype = "unknown";
+ match self {
+ Statement::Block(_) => { stype = "block"},
+ Statement::Break(_) => { stype = "break"},
+ Statement::BuiltinFunction(_) => { stype = "builtin function"},
+ Statement::Class(_) => { stype = "class"},
+ Statement::Continue(_) => { stype = "continue"},
+ Statement::Expression(_) => { stype = "expression"},
+ Statement::For(_) => { stype = "for"},
+ Statement::Function(_) => { stype = "function"},
+ Statement::If(_) => { stype = "if"},
+ Statement::Label(_) => { stype = "label"},
+ Statement::Return(_) => { stype = "return"},
+ Statement::Var(_) => { stype = "var"},
+ _ => {
+ stype = "other"
+ },
+ }
+ write!(f, "{}", stype)
  }
 }
 
@@ -97,6 +119,13 @@ pub struct IfStatement {
  pub else_statement: Box<Statement>,
 }
 
+#[derive(Debug, Clone, PartialEq)]
+pub struct LabeledStatement {
+ pub label: IdentifierLiteral,
+ pub statement: Box<Statement>,
+}
+
+
 #[derive(Debug, Clone, PartialEq)]
 pub struct ForStatement {
  pub initializer: Box<Statement>,
@@ -147,6 +176,16 @@ pub struct ReturnStatement {
  pub expression: Expression
 }
 
+#[derive(Debug, Clone, PartialEq)]
+pub struct BreakStatement {
+ pub label: Option<IdentifierLiteral>
+}
+
+#[derive(Debug, Clone, PartialEq)]
+pub struct ContinueStatement {
+ pub label: Option<IdentifierLiteral>
+}
+
 #[derive(Debug, Clone, PartialEq)]
 pub struct Parameter {
  pub name: IdentifierLiteral,