lib/mbstring/rtou8.c


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#include <stddef.h>

#include "mbstring.h"
#include "rune.h"

int
rtou8(char8_t *s, rune ch, size_t n)
{
	if (ch <= U8_1B_MAX) {
		if (n >= 1)
			s[0] = ch;
		return 1;
	} else if (ch <= U8_2B_MAX) {
		if (n >= 2) {
			s[0] = (ch >> 6) | 0xC0;
			s[1] = (ch & 0x3F) | 0x80;
		}
		return 2;
	} else if (ch <= U8_3B_MAX) {
		if (n >= 3) {
			s[0] = (ch >> 12) | 0xE0;
			s[1] = ((ch >> 6) & 0x3F) | 0x80;
			s[2] = (ch & 0x3F) | 0x80;
		}
		return 3;
	} else if (ch <= U8_4B_MAX) {
		if (n >= 4) {
			s[0] = (ch >> 18) | 0xF0;
			s[1] = ((ch >> 12) & 0x3F) | 0x80;
			s[2] = ((ch >> 6) & 0x3F) | 0x80;
			s[3] = (ch & 0x3F) | 0x80;
		}
		return 4;
	}

	return rtou8(s, RUNE_ERROR, n);
}