1 files changed, 56 insertions, 0 deletions
diff --git a/libcharconv_double_struck.c b/libcharconv_double_struck.c
new file mode 100644
index 0000000..de29727
--- /dev/null
+++ b/libcharconv_double_struck.c
@@ -0,0 +1,56 @@
+/* See LICENSE file for copyright and license details. */
+#include "libcharconv.h"
+
+
+enum libcharconv_result
+libcharconv_double_struck(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 == 'C') {
+			c = (uint_least32_t)UINT32_C(0x2102);
+			goto conv;
+		} else if (*s == 'H') {
+			c = (uint_least32_t)UINT32_C(0x210D);
+			goto conv;
+		} else if (*s == 'N') {
+			c = (uint_least32_t)UINT32_C(0x2115);
+			goto conv;
+		} else if (*s == 'P') {
+			c = (uint_least32_t)UINT32_C(0x2119);
+			goto conv;
+		} else if (*s == 'Q') {
+			c = (uint_least32_t)UINT32_C(0x211A);
+			goto conv;
+		} else if (*s == 'R') {
+			c = (uint_least32_t)UINT32_C(0x211D);
+			goto conv;
+		} else if (*s == 'Z') {
+			c = (uint_least32_t)UINT32_C(0x2124);
+			goto conv;
+		} else if ('A' <= *s && *s <= 'Z') {
+			c = (uint_least32_t)(UINT32_C(0x1D538) + (unsigned)(*s - 'A'));
+			goto conv;
+		} else if ('a' <= *s && *s <= 'z') {
+			c = (uint_least32_t)(UINT32_C(0x1D552) + (unsigned)(*s - 'a'));
+			goto conv;
+		} else if ('0' <= *s && *s <= '9') {
+			c = (uint_least32_t)(UINT32_C(0x1D7D8) + (unsigned)(*s - '0'));
+			goto conv;
+		} else {
+			*n += 1u;
+		}
+	}
+no_conv:
+	return LIBCHARCONV_NO_CONVERT;
+
+conv:
+	if (*n)
+		goto no_conv;
+	if (*ncp)
+		*cp = c;
+	*n += 1u;
+	*ncp = 1u;
+	return LIBCHARCONV_CONVERTED;
+}