1 files changed, 20 insertions, 0 deletions
diff --git a/internal/hex.go b/internal/hex.go
new file mode 100644
index 0000000..9ef78eb
--- /dev/null
+++ b/internal/hex.go
@@ -0,0 +1,20 @@
+// Copyright (C) 2022-2023  Luke Shumaker <lukeshu@lukeshu.com>
+//
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+package internal
+
+const Hex = "0123456789abcdef"
+
+func HexToInt[T interface{ byte | rune }](c T) (byte, bool) {
+	switch {
+	case '0' <= c && c <= '9':
+		return byte(c) - '0', true
+	case 'a' <= c && c <= 'f':
+		return byte(c) - 'a' + 10, true
+	case 'A' <= c && c <= 'F':
+		return byte(c) - 'A' + 10, true
+	default:
+		return 0, false
+	}
+}