Add variation selectors

Signed-off-by: Mattias Andrée <m@maandree.se>

1 files changed, 54 insertions, 0 deletions

diff --git a/libcharconv_variation_selectors.c b/libcharconv_variation_selectors.c
new file mode 100644
index 0000000..a5ec8e0
--- /dev/null
+++ b/libcharconv_variation_selectors.c
@@ -0,0 +1,54 @@
+/* See LICENSE file for copyright and license details. */
+#include "lib-common.h"
+
+
+enum libcharconv_result
+libcharconv_variation_selectors(const char *s, size_t slen, size_t *n, uint_least32_t *cp, size_t *ncp)
+{
+	enum libcharconv_result ret = LIBCHARCONV_CONVERTED;
+	uint_least32_t c;
+	*n = 0;
+	for (; slen--; s++) {
+		if ('1' <= s[0] && s[0] <= '9') {
+			c = (uint_least32_t)(s[0] - '0');
+			if (!slen--)
+				goto conv_if_end;
+			if ('0' > s[1] || s[1] > '9')
+				goto conv;
+			c *= 10u;
+			c += (uint_least32_t)(s[1] - '0');
+			if (!slen--)
+				goto conv_if_end;
+			if ('0' > s[2] || s[2] > '9')
+				goto conv;
+			c *= 10u;
+			c += (uint_least32_t)(s[2] - '0');
+			if (c > 256u) {
+				c /= 10u;
+				goto conv;
+			}
+			goto conv;
+		} else {
+			*n += 1u;
+			break;
+		}
+	}
+no_conv:
+	return LIBCHARCONV_NO_CONVERT;
+
+conv_if_end:
+	ret = LIBCHARCONV_CONVERT_IF_END;
+conv:
+	if (*n)
+		goto no_conv;
+	*n = c < 10u ? 1u : c < 100u ? 2u : 3u;
+	if (c < 17u)
+		c = UINT32_C(0xFE00) + (c - 1u);
+	else
+		c = UINT32_C(0xE0100) + (c - 17u);
+	if (*ncp)
+		*cp = c;
+	*ncp = 1u;
+	return ret;
+
+}