1 files changed, 42 insertions, 0 deletions
diff --git a/src/u8c/isdigit.c b/src/u8c/isdigit.c
new file mode 100644
index 0000000..1d5e35f
--- /dev/null
+++ b/src/u8c/isdigit.c
@@ -0,0 +1,42 @@
+/*
+	Copyright 2021 Gabriel Jensen
+
+	This file is part of u8c.
+
+	u8c is free software: you can redistribute it and/or modify it under the terms of the GNU Affero General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version.
+
+	u8c is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
+
+	See the	GNU Affero General Public License for more details.
+
+	You should have received a copy of the GNU Affero General Public License along with u8c.
+
+	If not, see <https://www.gnu.org/licenses/>.
+*/
+# include <assert.h>
+# include <stddef.h>
+# include <stdint.h>
+# include <u8c/isdigit.h>
+uint_least8_t u8c_isdigit(uint_least8_t * const _res,uint_least32_t _chr) {
+	assert(_res != NULL);
+	switch(_chr) {
+	default:
+		*_res = UINT8_C(0x0);
+		break;
+	case UINT32_C(0x30):   /* DIGIT ZERO */
+	case UINT32_C(0x31):   /* DIGIT ONE */
+	case UINT32_C(0x32):   /* DIGIT TWO */
+	case UINT32_C(0x33):   /* DIGIT THREE */
+	case UINT32_C(0x34):   /* DIGIT FOUR */
+	case UINT32_C(0x35):   /* DIGIT FIVE */
+	case UINT32_C(0x36):   /* DIGIT SIX */
+	case UINT32_C(0x37):   /* DIGIT SEVEN */
+	case UINT32_C(0x38):   /* DIGIT EIGHT */
+	case UINT32_C(0x39):   /* DIGIT NINE */
+	case UINT32_C(0x218A): /* TURNED DIGIT TWO */
+	case UINT32_C(0x218B): /* TURNED DIGIT THREE */
+		*_res = UINT8_C(0x1);
+		break;
+	}
+	return UINT8_C(0x0);
+}