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ladybird/Libraries/LibJS/Lexer.h

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LibJS: Add Javascript lexer and parser This adds a basic Javascript lexer and parser. It can parse the currently existing demo programs. More work needs to be done to turn it into a complete parser than can parse arbitrary JS Code. The lexer outputs tokens with preceeding whitespace and comments in the trivia member. This should allow us to generate the exact source code by concatenating the generated tokens. The parser is written in a way that it always returns a complete syntax tree. Error conditions are represented as nodes in the tree. This simplifies the code and allows it to be used as an early stage parser, e.g for parsing JS documents in an IDE while editing the source code.:
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/*
* Copyright (c) 2020, Stephan Unverwerth <s.unverwerth@gmx.de>
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* 1. Redistributions of source code must retain the above copyright notice, this
* list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
* SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
* CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#pragma once
#include "Token.h"
#include <AK/HashMap.h>
#include <AK/String.h>
#include <AK/StringView.h>
namespace JS {
class Lexer {
public:
explicit Lexer(StringView source);
Token next();
LibJS: Lex single quote strings, escaped chars and unterminated strings
2020-03-14 10:45:25 +00:00
bool has_errors() const { return m_has_errors; }
LibJS: Add Javascript lexer and parser This adds a basic Javascript lexer and parser. It can parse the currently existing demo programs. More work needs to be done to turn it into a complete parser than can parse arbitrary JS Code. The lexer outputs tokens with preceeding whitespace and comments in the trivia member. This should allow us to generate the exact source code by concatenating the generated tokens. The parser is written in a way that it always returns a complete syntax tree. Error conditions are represented as nodes in the tree. This simplifies the code and allows it to be used as an early stage parser, e.g for parsing JS documents in an IDE while editing the source code.:
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private:
void consume();
bool is_eof() const;
bool is_identifier_start() const;
bool is_identifier_middle() const;
bool is_line_comment_start() const;
bool is_block_comment_start() const;
bool is_block_comment_end() const;
LibJS: Lex single quote strings, escaped chars and unterminated strings
2020-03-14 10:45:25 +00:00
void syntax_error(const char*);
LibJS: Add Javascript lexer and parser This adds a basic Javascript lexer and parser. It can parse the currently existing demo programs. More work needs to be done to turn it into a complete parser than can parse arbitrary JS Code. The lexer outputs tokens with preceeding whitespace and comments in the trivia member. This should allow us to generate the exact source code by concatenating the generated tokens. The parser is written in a way that it always returns a complete syntax tree. Error conditions are represented as nodes in the tree. This simplifies the code and allows it to be used as an early stage parser, e.g for parsing JS documents in an IDE while editing the source code.:
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StringView m_source;
size_t m_position = 0;
Token m_current_token;
LibJS: Plumb line and column information through Lexer / Parser While debugging test failures, it's pretty frustrating to have to go do printf debugging to figure out what test is failing right now. While watching your JS Raytracer stream it seemed like this was pretty furstrating as well. So I wanted to start working on improving the diagnostics here. In the future I hope we can eventually be able to plumb the info down to the Error classes so any thrown exceptions will contain enough metadata to know where they came from.
2020-04-05 09:34:03 +00:00
int m_current_char = 0;
LibJS: Lex single quote strings, escaped chars and unterminated strings
2020-03-14 10:45:25 +00:00
bool m_has_errors = false;
LibJS: Plumb line and column information through Lexer / Parser While debugging test failures, it's pretty frustrating to have to go do printf debugging to figure out what test is failing right now. While watching your JS Raytracer stream it seemed like this was pretty furstrating as well. So I wanted to start working on improving the diagnostics here. In the future I hope we can eventually be able to plumb the info down to the Error classes so any thrown exceptions will contain enough metadata to know where they came from.
2020-04-05 09:34:03 +00:00
size_t m_line_number = 1;
size_t m_line_column = 1;
LibJS: Add Javascript lexer and parser This adds a basic Javascript lexer and parser. It can parse the currently existing demo programs. More work needs to be done to turn it into a complete parser than can parse arbitrary JS Code. The lexer outputs tokens with preceeding whitespace and comments in the trivia member. This should allow us to generate the exact source code by concatenating the generated tokens. The parser is written in a way that it always returns a complete syntax tree. Error conditions are represented as nodes in the tree. This simplifies the code and allows it to be used as an early stage parser, e.g for parsing JS documents in an IDE while editing the source code.:
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static HashMap<String, TokenType> s_keywords;
LibJS: Parse === and !== binary operators
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static HashMap<String, TokenType> s_three_char_tokens;
LibJS: Add Javascript lexer and parser This adds a basic Javascript lexer and parser. It can parse the currently existing demo programs. More work needs to be done to turn it into a complete parser than can parse arbitrary JS Code. The lexer outputs tokens with preceeding whitespace and comments in the trivia member. This should allow us to generate the exact source code by concatenating the generated tokens. The parser is written in a way that it always returns a complete syntax tree. Error conditions are represented as nodes in the tree. This simplifies the code and allows it to be used as an early stage parser, e.g for parsing JS documents in an IDE while editing the source code.:
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static HashMap<String, TokenType> s_two_char_tokens;
static HashMap<char, TokenType> s_single_char_tokens;
};
}
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