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feat: arrow function (#12)
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* feat: arrow function

* docs: update passed data

* chore: test

* test: 262 diff

* fix: arrow function duplicate parameter name error

* fix: Invalid left-hand side in assignment

* feat: arrow function
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@echosoar
echosoar authored Mar 26, 2023
1 parent b9bf224 commit ae18be3
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Showing 14 changed files with 369 additions and 46 deletions.
3 changes: 2 additions & 1 deletion .gitignore
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@@ -1,3 +1,4 @@
/target
.test
262_result.json
262_result.json
262_result_diff.json
2 changes: 1 addition & 1 deletion readme.md
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Expand Up @@ -3,7 +3,7 @@
JSI is a JavaScript Interpreter written in Rust.


<img src="https://img.shields.io/badge/Test262-3543%20Passed-brightgreen.svg" alt="test262 passed" />
<img src="https://img.shields.io/badge/Test262-3999%20Passed-brightgreen.svg" alt="test262 passed" />
<img src="https://img.shields.io/badge/Test262-46442%20Total-blue.svg" alt="test262 total" />

---
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154 changes: 146 additions & 8 deletions src/ast.rs
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Original file line number Diff line number Diff line change
@@ -1,12 +1,14 @@
use std::collections::HashMap;
// AST
// mod super::token::TokenKeywords;
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, BreakStatement, ContinueStatement, LabeledStatement, SwitchStatement, CaseClause, NewExpression, TryCatchStatement, CatchClause, ThrowStatement, TemplateLiteralExpression};
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, SwitchStatement, CaseClause, NewExpression, TryCatchStatement, CatchClause, ThrowStatement, TemplateLiteralExpression, SequenceExpression};
use crate::ast_utils::{get_hex_number_value, chars_to_string};
use crate::error::{JSIResult, JSIError, JSIErrorType};
pub struct AST {
strict: bool,
// 当前字符
char: char,
// 下一个字符的索引
Expand All @@ -29,13 +31,16 @@ pub struct AST {
pre_token_need_semicolon: bool,
// 当碰到换行时，是否需要自动添加 semicolon
auto_semicolon_when_new_line: bool,
// 不声明方法到作用域，当方法定义咋 while 的条件中
not_declare_function_to_scope: bool,
}

impl AST{
pub fn new(code: String) -> AST{
let chars: Vec<char> = code.chars().collect();
let len = chars.len();
AST {
strict: true,
char: ' ',
next_char_index: 0,
cur_char_index: 0,
Expand All @@ -47,9 +52,14 @@ impl AST{
scope: ASTScope::new(),
pre_token_need_semicolon: false,
auto_semicolon_when_new_line: false,
not_declare_function_to_scope: false,
}
}

pub fn set_strict(&mut self,strict: bool) {
self.strict = strict;
}

// 解析生成 Program
pub fn parse(&mut self) -> JSIResult<Program> {
self.next();
Expand Down Expand Up @@ -105,7 +115,7 @@ impl AST{
// 解析生成 statement
fn parse_statement(&mut self) -> JSIResult<Statement> {
// println!("parse_statement: {:?} {:?}", self.token, self.literal);
match self.token {
let statment = match self.token {
Token::Var | Token::Let | Token::Const => self.parse_variable_statement(),
Token::If => self.parse_if_statement(),
Token::Switch => self.parse_switch_statement(),
Expand Down Expand Up @@ -134,7 +144,7 @@ impl AST{
},
_ => {
let expression = self.parse_expression()?;

// println!("statement expression {:?}", expression);
// label:
if self.token == Token::Colon {
if let Expression::Identifier(identifier) = expression {
Expand All @@ -160,7 +170,16 @@ impl AST{
}
}
},
};

loop {
if self.token == Token::Semicolon {
self.next();
} else {
break;
}
}
return statment;
}

// 解析 let / var
Expand Down Expand Up @@ -298,7 +317,9 @@ impl AST{
initializer = Statement::Expression(ExpressionStatement { expression: self.parse_expression()? });
self.check_token_and_next(Token::Semicolon)?;
}
self.not_declare_function_to_scope = true;
let condition = self.parse_expression()?;
self.not_declare_function_to_scope = false;
self.check_token_and_next(Token::Semicolon)?;
let incrementor = self.parse_expression()?;
self.check_token_and_next(Token::RightParenthesis)?;
Expand All @@ -318,7 +339,9 @@ impl AST{
fn parse_while_statement(&mut self) -> JSIResult<Statement> {
self.check_token_and_next(Token::While)?;
self.check_token_and_next(Token::LeftParenthesis)?;
self.not_declare_function_to_scope = true;
let condition = self.parse_expression()?;
self.not_declare_function_to_scope = false;
self.check_token_and_next(Token::RightParenthesis)?;

let block = self.parse_block_statement()?;
Expand All @@ -339,7 +362,9 @@ impl AST{
let block = self.parse_block_statement()?;
self.check_token_and_next(Token::While)?;
self.check_token_and_next(Token::LeftParenthesis)?;
self.not_declare_function_to_scope = true;
let condition = self.parse_expression()?;
self.not_declare_function_to_scope = false;
self.check_token_and_next(Token::RightParenthesis)?;
let statement = ForStatement {
initializer: Box::new(Statement::Unknown),
Expand Down Expand Up @@ -422,11 +447,14 @@ impl AST{
// 解析参数
// 左括号
let mut parameters: Vec<Parameter> = vec![];
let mut parameters_names: HashMap<String, bool> = HashMap::new();
self.check_token_and_next(Token::LeftParenthesis)?;
while self.token != Token::RightParenthesis && self.token != Token::EOF {
if self.token == Token::Identifier {
let literal = self.literal.clone();
self.check_function_parameters_duplicate(&mut parameters_names, &literal)?;
parameters.push(Parameter{
name: IdentifierLiteral { literal: self.literal.clone() },
name: IdentifierLiteral { literal: literal },
initializer: Box::new(Expression::Keyword(Keywords::Undefined)),
});
self.next()
Expand All @@ -451,17 +479,91 @@ impl AST{
self.close_scope();
let func = FunctionDeclaration {
is_anonymous,
is_arrow: false,
name: IdentifierLiteral { literal: name },
parameters,
body,
declarations,
};
if variable_lifting && !is_anonymous {
if variable_lifting && !is_anonymous && !self.not_declare_function_to_scope {
self.scope.declare(Declaration::Function(func.clone()));
}
return Ok(func);
}

// 检测函数参数是否重名
fn check_function_parameters_duplicate(&mut self, parameters_name: &mut HashMap<String, bool>, parameter_name: &String) -> JSIResult<bool> {
if !self.strict {
return Ok(true);
}
if let Some(_) = parameters_name.get(parameter_name) {
return Err(JSIError::new(JSIErrorType::SyntaxError, String::from("Duplicate parameter name not allowed in this context"), 0, 0));
} else {
parameters_name.insert(parameter_name.clone(), true);
}
return Ok(true);
}

fn parse_arrow_function(&mut self, params: Expression) -> JSIResult<Expression> {
let mut parameters: Vec<Parameter> = vec![];
let mut parameters_names: HashMap<String, bool> = HashMap::new();
match params {
Expression::Identifier(iden) => {
self.check_function_parameters_duplicate(&mut parameters_names, &iden.literal)?;
parameters.push(Parameter { name: iden.to_owned(), initializer: Box::new(Expression::Keyword(Keywords::Undefined)) });
},
// TODO: assign
Expression::Sequence(sequence) => {
for expr in sequence.expressions.iter() {
match expr {
Expression::Identifier(iden) => {
self.check_function_parameters_duplicate(&mut parameters_names, &iden.literal)?;
parameters.push(Parameter { name: iden.to_owned(), initializer: Box::new(Expression::Keyword(Keywords::Undefined)) });
},
// TODO: assign
_ => {}
}
}
},
_ => {}
}

// 解析方法体
if self.token == Token::LeftBrace {
self.new_scope();
let body_statement = self.parse_block_statement()?;
let body = match body_statement {
Statement::Block(block) => block,
_ => BlockStatement { statements: vec![] }
};
let declarations = self.scope.declarations.clone();
self.close_scope();
let func = FunctionDeclaration {
is_anonymous: true,
is_arrow: true,
name: IdentifierLiteral { literal: String::new() },
parameters,
body,
declarations,
};
Ok(Expression::Function(func))
} else {
let expr = self.parse_expression()?;
let func = FunctionDeclaration {
is_anonymous: true,
is_arrow: true,
name: IdentifierLiteral { literal: String::new() },
parameters,
body: BlockStatement { statements: vec![
Statement::Return(ReturnStatement { expression: expr }),
] },
declarations: vec![],
};
Ok(Expression::Function(func))
}

}

// 解析 class(ES2015)
fn parse_class(&mut self) -> JSIResult<ClassDeclaration> {
self.check_token_and_next(Token::Class)?;
Expand Down Expand Up @@ -1175,15 +1277,41 @@ impl AST{
// 解析表达式
fn parse_expression(&mut self) -> JSIResult<Expression> {
let res = self.parse_assignment_expression();
// println!("parse_expression {:?}", res);
res
}

// 解析逗号运算符，虽然优先级最高，但是一般只在匹配到左括号/左中括号时调用
fn parse_comma_expression(&mut self) -> JSIResult<Expression> {
let left = self.parse_expression()?;
if self.token == Token::Comma {
let mut exprs: Vec<Expression> = vec![left];
loop {
if self.token != Token::Comma {
break
}
self.next();
let next_expr = self.parse_expression()?;
exprs.push(next_expr);
}
return Ok(Expression::Sequence(SequenceExpression {
expressions: exprs
}));
}
return Ok(left);
}

// 解析赋值运算符，优先级 2，从右到左
// https://tc39.es/ecma262/multipage/ecmascript-language-expressions.html#sec-assignment-operators
fn parse_assignment_expression(&mut self) -> JSIResult<Expression> {
let left = self.parse_conditional_expression()?;
match self.token {
Token::Assign | Token::AddAssign | Token::SubtractAssign | Token::MultiplyAssign | Token::SlashAssign | Token::RemainderAssign | Token::ShiftLeftAssign | Token::ShiftRightAssign | Token::UnsignedShiftRightAssign | Token::OrAssign | Token::AndAssign | Token::ExclusiveOrAssign | Token::LogicalAndAssign | Token::LogicalOrAssign | Token::ExponentiationAssign | Token::NullishCoalescingAssign => {

if !left.is_assignment_target_type() {
return Err(JSIError::new(JSIErrorType::SyntaxError, String::from("Invalid left-hand side in assignment"), 0, 0))
}

// 跳过各种赋值运算符
let oper = self.token.clone();
self.next();
Expand All @@ -1196,7 +1324,6 @@ impl AST{
}));
},
_ => Ok(left)

}
}

Expand Down Expand Up @@ -1415,6 +1542,14 @@ impl AST{
// ref: https://tc39.es/ecma262/multipage/ecmascript-language-expressions.html#sec-left-hand-side-expressions
fn parse_left_hand_side_expression(&mut self) -> JSIResult<Expression> {
let mut left = self.parse_group_expression()?;
if self.token == Token::Assign && self.char == '>' {
if self.auto_semicolon_when_new_line {
return Err(JSIError::new(JSIErrorType::SyntaxError, format!("Unexpected token '=>'"), 0, 0));
}
self.next();
self.next();
return self.parse_arrow_function(left);
}
loop {
self.cur_expr = left.clone();
let new_left = match self.token {
Expand Down Expand Up @@ -1496,8 +1631,11 @@ impl AST{
fn parse_group_expression(&mut self) -> JSIResult<Expression> {
if self.token == Token::LeftParenthesis {
self.next();
let expr = self.parse_expression()?;
let expr = self.parse_comma_expression()?;
self.check_token_and_next(Token::RightParenthesis)?;
if let Expression::Sequence(_) = &expr {
return Ok(expr);
}
return Ok(Expression::Group(GroupExpression {
expression: Box::new(expr),
}))
Expand Down Expand Up @@ -1791,7 +1929,7 @@ impl AST{
Token::String => String::from("Unexpected string"),
_ => format!("Unexpected token {:?}", self.token),
};
println!("token:{:?}", self.literal);
// panic!("token:{:?}", self.literal);
// TODO: line column
JSIError::new(JSIErrorType::SyntaxError, message, 0, 0)
}
Expand Down
22 changes: 22 additions & 0 deletions src/ast_node.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -85,6 +85,7 @@ pub enum Expression {
Array(ArrayLiteral),
Function(FunctionDeclaration),
New(NewExpression),
Sequence(SequenceExpression),
TemplateLiteral(TemplateLiteralExpression),
// {[a]: 12}
ComputedPropertyName(ComputedPropertyName),
Expand All @@ -94,6 +95,20 @@ pub enum Expression {
ClassMethod(ClassMethodDeclaration),
Unknown,
}
impl Expression {
// https://tc39.es/ecma262/multipage/syntax-directed-operations.html#sec-static-semantics-assignmenttargettype
pub fn is_assignment_target_type(&self) -> bool {
match self {
Expression::Identifier(_) => true,
Expression::PropertyAccess(_) => true,
Expression::ElementAccess(_) => true,
Expression::Group(group) => {
return group.expression.is_assignment_target_type();
},
_ => false
}
}
}

#[derive(Debug,Clone, PartialEq)]
pub enum Keywords {
Expand Down Expand Up @@ -196,6 +211,7 @@ pub struct CatchClause {
#[derive(Debug, Clone, PartialEq)]
pub struct FunctionDeclaration {
pub is_anonymous: bool,
pub is_arrow: bool,
pub name: IdentifierLiteral,
pub parameters: Vec<Parameter>,
pub body: BlockStatement,
Expand Down Expand Up @@ -318,6 +334,12 @@ pub struct PostfixUnaryExpression {
pub operator: Token,
}

// 字符串模板表达式
#[derive(Debug, Clone, PartialEq)]
pub struct SequenceExpression {
pub expressions: Vec<Expression>
}

// 字符串模板表达式
#[derive(Debug, Clone, PartialEq)]
pub struct TemplateLiteralExpression {
Expand Down
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