lsnes/include/library/utf8.hpp
2013-12-21 16:36:33 +02:00

66 lines
1.3 KiB
C++

#ifndef _library__utf8__hpp__included__
#define _library__utf8__hpp__included__
#include <iostream>
#include <cstdint>
#include <cstdlib>
#include <string>
#include <functional>
namespace utf8
{
/**
* Initial state for UTF-8 parser.
*/
extern const uint16_t initial_state;
/**
* Parse a byte.
*
* Parameter ch: The character to parse. -1 for end of string.
* Parameter state: The state. Mutated.
* Returns: The codepoint, or -1 if no codepoint emitted.
*
* Note: When called with EOF, max 1 codepoint can be emitted.
*/
int32_t parse_byte(int ch, uint16_t& state) throw();
/**
* Return length of string in UTF-8 codepoints.
*
* Parameter str: The string.
* Returns: The length in codepoints.
*/
size_t strlen(const std::string& str) throw();
/**
* Transform UTF-8 into UTF-32.
*/
std::u32string to32(const std::string& utf8);
/**
* Transform UTF-32 into UTF-8.
*/
std::string to8(const std::u32string& utf32);
/**
* Iterator copy from UTF-8 to UTF-32
*/
template<typename srcitr, typename dstitr>
inline void to32i(srcitr begin, srcitr end, dstitr target)
{
uint16_t state = initial_state;
for(srcitr i = begin; i != end; i++) {
int32_t x = parse_byte((unsigned char)*i, state);
if(x >= 0) {
*target = x;
++target;
}
}
int32_t x = parse_byte(-1, state);
if(x >= 0) {
*target = x;
++target;
}
}
}
#endif