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