ladybird/Libraries/LibRegex/RegexLexer.h
AnotherTest dbef2b1ee9 LibRegex: Implement an ECMA262-compatible parser
This also adds support for lookarounds and individually-negated
comparisons.
The only unimplemented part of the parser spec is the unicode stuff.
2020-11-27 21:32:41 +01:00

111 lines
3.8 KiB
C++

/*
* Copyright (c) 2020, Emanuel Sprung <emanuel.sprung@gmail.com>
* 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 <AK/Forward.h>
#include <AK/StringView.h>
namespace regex {
#define ENUMERATE_REGEX_TOKENS \
__ENUMERATE_REGEX_TOKEN(Eof) \
__ENUMERATE_REGEX_TOKEN(Char) \
__ENUMERATE_REGEX_TOKEN(Circumflex) \
__ENUMERATE_REGEX_TOKEN(Period) \
__ENUMERATE_REGEX_TOKEN(LeftParen) \
__ENUMERATE_REGEX_TOKEN(RightParen) \
__ENUMERATE_REGEX_TOKEN(LeftCurly) \
__ENUMERATE_REGEX_TOKEN(RightCurly) \
__ENUMERATE_REGEX_TOKEN(LeftBracket) \
__ENUMERATE_REGEX_TOKEN(RightBracket) \
__ENUMERATE_REGEX_TOKEN(Asterisk) \
__ENUMERATE_REGEX_TOKEN(EscapeSequence) \
__ENUMERATE_REGEX_TOKEN(Dollar) \
__ENUMERATE_REGEX_TOKEN(Pipe) \
__ENUMERATE_REGEX_TOKEN(Plus) \
__ENUMERATE_REGEX_TOKEN(Comma) \
__ENUMERATE_REGEX_TOKEN(Slash) \
__ENUMERATE_REGEX_TOKEN(EqualSign) \
__ENUMERATE_REGEX_TOKEN(HyphenMinus) \
__ENUMERATE_REGEX_TOKEN(Colon) \
__ENUMERATE_REGEX_TOKEN(Questionmark)
enum class TokenType {
#define __ENUMERATE_REGEX_TOKEN(x) x,
ENUMERATE_REGEX_TOKENS
#undef __ENUMERATE_REGEX_TOKEN
};
class Token {
public:
Token() = default;
Token(const TokenType type, const size_t start_position, const StringView value)
: m_type(type)
, m_position(start_position)
, m_value(value)
{
}
TokenType type() const { return m_type; }
const StringView& value() const { return m_value; }
size_t position() const { return m_position; }
const char* name() const;
static const char* name(const TokenType);
private:
TokenType m_type { TokenType::Eof };
size_t m_position { 0 };
StringView m_value { nullptr };
};
class Lexer {
public:
Lexer() = default;
explicit Lexer(const StringView source);
Token next();
void reset();
void back(size_t offset);
void set_source(const StringView source) { m_source = source; }
bool try_skip(char);
StringView slice_back(size_t offset) const { return m_source.substring_view(m_position - offset - 1, offset); }
private:
ALWAYS_INLINE char peek(size_t offset = 0) const;
ALWAYS_INLINE void consume();
StringView m_source {};
size_t m_position { 0 };
size_t m_previous_position { 0 };
Token m_current_token { TokenType::Eof, 0, StringView(nullptr) };
int m_current_char { 0 };
};
}
using regex::Lexer;