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	 d476144565
			
		
	
	
		d476144565
		
	
	
	
	
		
			
			Some of the code assumed that chars were always signed while that is not the case on ARM hosts. Also, some of the code tried to use EOF (-1) in a way similar to what fgetc() does, however instead of storing the characters in an int variable a char was used. While this seemed to work it also meant that character 0xFF would be incorrectly seen as an end-of-file. Careful reading of fgetc() reveals that fgetc() stores character data in an int where valid characters are in the range of 0-255 and the EOF value is explicitly outside of that range (usually -1).
		
			
				
	
	
		
			91 lines
		
	
	
	
		
			2.5 KiB
		
	
	
	
		
			C++
		
	
	
	
	
	
			
		
		
	
	
			91 lines
		
	
	
	
		
			2.5 KiB
		
	
	
	
		
			C++
		
	
	
	
	
	
| /*
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|  * Copyright (c) 2020, Emanuel Sprung <emanuel.sprung@gmail.com>
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|  *
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|  * SPDX-License-Identifier: BSD-2-Clause
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|  */
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| 
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| #pragma once
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| 
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| #include <AK/Forward.h>
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| #include <AK/StringView.h>
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| 
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| namespace regex {
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| 
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| #define ENUMERATE_REGEX_TOKENS              \
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|     __ENUMERATE_REGEX_TOKEN(Eof)            \
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|     __ENUMERATE_REGEX_TOKEN(Char)           \
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|     __ENUMERATE_REGEX_TOKEN(Circumflex)     \
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|     __ENUMERATE_REGEX_TOKEN(Period)         \
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|     __ENUMERATE_REGEX_TOKEN(LeftParen)      \
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|     __ENUMERATE_REGEX_TOKEN(RightParen)     \
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|     __ENUMERATE_REGEX_TOKEN(LeftCurly)      \
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|     __ENUMERATE_REGEX_TOKEN(RightCurly)     \
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|     __ENUMERATE_REGEX_TOKEN(LeftBracket)    \
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|     __ENUMERATE_REGEX_TOKEN(RightBracket)   \
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|     __ENUMERATE_REGEX_TOKEN(Asterisk)       \
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|     __ENUMERATE_REGEX_TOKEN(EscapeSequence) \
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|     __ENUMERATE_REGEX_TOKEN(Dollar)         \
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|     __ENUMERATE_REGEX_TOKEN(Pipe)           \
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|     __ENUMERATE_REGEX_TOKEN(Plus)           \
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|     __ENUMERATE_REGEX_TOKEN(Comma)          \
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|     __ENUMERATE_REGEX_TOKEN(Slash)          \
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|     __ENUMERATE_REGEX_TOKEN(EqualSign)      \
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|     __ENUMERATE_REGEX_TOKEN(HyphenMinus)    \
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|     __ENUMERATE_REGEX_TOKEN(Colon)          \
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|     __ENUMERATE_REGEX_TOKEN(Questionmark)
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| 
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| enum class TokenType {
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| #define __ENUMERATE_REGEX_TOKEN(x) x,
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|     ENUMERATE_REGEX_TOKENS
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| #undef __ENUMERATE_REGEX_TOKEN
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| };
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| 
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| class Token {
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| public:
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|     Token() = default;
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|     Token(const TokenType type, const size_t start_position, const StringView value)
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|         : m_type(type)
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|         , m_position(start_position)
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|         , m_value(value)
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|     {
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|     }
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| 
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|     TokenType type() const { return m_type; }
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|     const StringView& value() const { return m_value; }
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|     size_t position() const { return m_position; }
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| 
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|     const char* name() const;
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|     static const char* name(const TokenType);
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| 
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| private:
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|     TokenType m_type { TokenType::Eof };
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|     size_t m_position { 0 };
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|     StringView m_value { nullptr };
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| };
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| 
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| class Lexer {
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| public:
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|     Lexer() = default;
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|     explicit Lexer(const StringView source);
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|     Token next();
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|     void reset();
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|     void back(size_t offset);
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|     void set_source(const StringView source) { m_source = source; }
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|     bool try_skip(char);
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|     char skip();
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|     const auto& source() const { return m_source; }
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| 
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| private:
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|     ALWAYS_INLINE int peek(size_t offset = 0) const;
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|     ALWAYS_INLINE void consume();
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| 
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|     StringView m_source {};
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|     size_t m_position { 0 };
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|     size_t m_previous_position { 0 };
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|     Token m_current_token { TokenType::Eof, 0, StringView(nullptr) };
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|     int m_current_char { 0 };
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| };
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| 
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| }
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| 
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| using regex::Lexer;
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