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/* MIT (BSD) license - see LICENSE file for details */
#ifndef CCAN_UTF8_H
#define CCAN_UTF8_H
#include <inttypes.h>
#include <stdbool.h>
#include <string.h>
/* Unicode is limited to 21 bits. */
#define UTF8_MAX_LEN 4
struct utf8_state {
/* How many characters we are expecting as part of this Unicode point */
uint16_t total_len;
/* How many characters we've already seen. */
uint16_t used_len;
/* Compound character, aka Unicode point. */
uint32_t c;
};
#define UTF8_STATE_INIT { 0, 0, 0 }
static inline void utf8_state_init(struct utf8_state *utf8_state)
{
memset(utf8_state, 0, sizeof(*utf8_state));
}
/**
* utf8_decode - continue UTF8 decoding with this character.
* @utf8_state - initialized UTF8 state.
* @c - the character.
*
* Returns false if it needs another character to give results.
* Otherwise returns true, @utf8_state can be reused without initializeation,
* and sets errno:
* 0: success
* EINVAL: bad encoding (including a NUL character).
* EFBIG: not a minimal encoding.
* ERANGE: encoding of invalid character.
*
* You can extract the character from @utf8_state->c; @utf8_state->used_len
* indicates how many characters have been consumed.
*/
bool utf8_decode(struct utf8_state *utf8_state, char c);
/**
* utf8_encode - encode a point into UTF8.
* @point - Unicode point to include.
* @dest - buffer to fill.
*
* Returns 0 if point was invalid, otherwise bytes of dest used.
* Sets errno to ERANGE if point was invalid.
*/
size_t utf8_encode(uint32_t point, char dest[UTF8_MAX_LEN]);
/* Check for valid UTF-8 */
bool utf8_check(const void *vbuf, size_t buflen);
#endif /* CCAN_UTF8_H */