libcharconv_superscript.c


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/* See LICENSE file for copyright and license details. */
#include "lib-common.h"


enum libcharconv_result
libcharconv_superscript(const char *s, size_t slen, size_t *n, uint_least32_t *cp, size_t *ncp)
{
	uint_least32_t c;
	*n = 0;
	for (; slen--; s++) {
		if (*s == '1') {
			c = (uint_least32_t)UINT32_C(0x00B9);
		} else if ('2' <= *s && *s <= '3') {
			c = (uint_least32_t)(UINT32_C(0x00B2) + (unsigned)(*s - '2'));
		} else if ('0' <= *s && *s <= '9') {
			c = (uint_least32_t)(UINT32_C(0x2070) + (unsigned)(*s - '0'));
		} else {
			*n += 1u;
			continue;
		}
		goto conv;
	}
no_conv:
	return LIBCHARCONV_NO_CONVERT;

conv:
	if (*n)
		goto no_conv;
	if (*ncp)
		*cp = c;
	*n += 1u;
	*ncp = 1u;
	return LIBCHARCONV_CONVERTED;
}