mirror of
https://github.com/RetroDECK/Duckstation.git
synced 2025-04-10 19:15:14 +00:00
113 lines
3.2 KiB
C++
113 lines
3.2 KiB
C++
/*
|
|
* Copyright (C) 2014 Patrick Mours
|
|
* SPDX-License-Identifier: BSD-3-Clause
|
|
*/
|
|
|
|
#pragma once
|
|
|
|
#include "effect_token.hpp"
|
|
|
|
namespace reshadefx
|
|
{
|
|
/// <summary>
|
|
/// A lexical analyzer for C-like languages.
|
|
/// </summary>
|
|
class lexer
|
|
{
|
|
public:
|
|
explicit lexer(
|
|
std::string input,
|
|
bool ignore_comments = true,
|
|
bool ignore_whitespace = true,
|
|
bool ignore_pp_directives = true,
|
|
bool ignore_line_directives = false,
|
|
bool ignore_keywords = false,
|
|
bool escape_string_literals = true,
|
|
const location &start_location = location()) :
|
|
_input(std::move(input)),
|
|
_cur_location(start_location),
|
|
_ignore_comments(ignore_comments),
|
|
_ignore_whitespace(ignore_whitespace),
|
|
_ignore_pp_directives(ignore_pp_directives),
|
|
_ignore_line_directives(ignore_line_directives),
|
|
_ignore_keywords(ignore_keywords),
|
|
_escape_string_literals(escape_string_literals)
|
|
{
|
|
_cur = _input.data();
|
|
_end = _cur + _input.size();
|
|
}
|
|
|
|
lexer(const lexer &lexer) { operator=(lexer); }
|
|
lexer &operator=(const lexer &lexer)
|
|
{
|
|
_input = lexer._input;
|
|
_cur_location = lexer._cur_location;
|
|
reset_to_offset(lexer._cur - lexer._input.data());
|
|
_end = _input.data() + _input.size();
|
|
_ignore_comments = lexer._ignore_comments;
|
|
_ignore_whitespace = lexer._ignore_whitespace;
|
|
_ignore_pp_directives = lexer._ignore_pp_directives;
|
|
_ignore_keywords = lexer._ignore_keywords;
|
|
_escape_string_literals = lexer._escape_string_literals;
|
|
_ignore_line_directives = lexer._ignore_line_directives;
|
|
|
|
return *this;
|
|
}
|
|
|
|
/// <summary>
|
|
/// Gets the current position in the input string.
|
|
/// </summary>
|
|
size_t input_offset() const { return _cur - _input.data(); }
|
|
|
|
/// <summary>
|
|
/// Gets the input string this lexical analyzer works on.
|
|
/// </summary>
|
|
/// <returns>Constant reference to the input string.</returns>
|
|
const std::string &input_string() const { return _input; }
|
|
|
|
/// <summary>
|
|
/// Performs lexical analysis on the input string and return the next token in sequence.
|
|
/// </summary>
|
|
/// <returns>Next token from the input string.</returns>
|
|
token lex();
|
|
|
|
/// <summary>
|
|
/// Advances to the next token that is not whitespace.
|
|
/// </summary>
|
|
void skip_space();
|
|
/// <summary>
|
|
/// Advances to the next new line, ignoring all tokens.
|
|
/// </summary>
|
|
void skip_to_next_line();
|
|
|
|
/// <summary>
|
|
/// Resets position to the specified <paramref name="offset"/>.
|
|
/// </summary>
|
|
/// <param name="offset">Offset in characters from the start of the input string.</param>
|
|
void reset_to_offset(size_t offset);
|
|
|
|
private:
|
|
/// <summary>
|
|
/// Skips an arbitrary amount of characters in the input string.
|
|
/// </summary>
|
|
/// <param name="length">Number of input characters to skip.</param>
|
|
void skip(size_t length);
|
|
|
|
void parse_identifier(token &tok) const;
|
|
bool parse_pp_directive(token &tok);
|
|
void parse_string_literal(token &tok, bool escape);
|
|
void parse_numeric_literal(token &tok) const;
|
|
|
|
std::string _input;
|
|
location _cur_location;
|
|
const std::string::value_type *_cur, *_end;
|
|
|
|
bool _ignore_comments;
|
|
bool _ignore_whitespace;
|
|
bool _ignore_pp_directives;
|
|
bool _ignore_line_directives;
|
|
bool _ignore_keywords;
|
|
bool _escape_string_literals;
|
|
};
|
|
}
|