Add braille

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

1 files changed, 62 insertions, 0 deletions

diff --git a/libcharconv_braille.c b/libcharconv_braille.c
new file mode 100644
index 0000000..3a9807e
--- /dev/null
+++ b/libcharconv_braille.c
@@ -0,0 +1,62 @@
+/* See LICENSE file for copyright and license details. */
+#include "lib-common.h"
+
+
+enum libcharconv_result
+libcharconv_braille(const char *s, size_t slen, size_t *n, uint_least32_t *cp, size_t *ncp)
+{
+	unsigned pattern, dot;
+	uint_least32_t c;
+	*n = 0;
+	for (; slen--; s++) {
+		if (s[0] == '0') {
+			if (*n)
+				goto no_conv;
+			c = UINT32_C(0x2800);
+			*n = 1u;
+			goto conv;
+		} else if ('1' <= s[0] && s[0] <= '8') {
+			if (*n)
+				goto no_conv;
+			pattern = 1u << (s[0] - '1');
+			*n = 1u;
+			for (;;) {
+				if (!slen--)
+					goto indeterminate;
+				if ('1' <= s[*n] && s[*n] <= '8') {
+					dot = 1u << (s[*n] - '1');
+					if (pattern & dot)
+						break;
+					pattern |= dot;
+					*n += 1u;
+				} else if (s[*n] == '0') {
+					*n += 1u;
+					break;
+				} else {
+					break;
+				}
+			}
+			c = UINT32_C(0x2800) | pattern;
+			goto conv;
+		} else {
+			*n += 1u;
+		}
+	}
+	return LIBCHARCONV_NO_CONVERT;
+
+no_conv:
+	if (!*n)
+		*n = 1u;
+	return LIBCHARCONV_NO_CONVERT;
+
+indeterminate:
+	if (*n)
+		goto no_conv;
+	return LIBCHARCONV_INDETERMINATE;
+
+conv:
+	if (*ncp)
+		*cp = c;
+	*ncp = 1u;
+	return LIBCHARCONV_CONVERTED;
+}