parse: Rework to avoid passing around function pointers

"Ignore whitespace" is probably essential for viewing this patch.

1 files changed, 13 insertions, 0 deletions

diff --git a/misc.go b/misc.go
index 132b177..a567cc7 100644
--- a/misc.go
+++ b/misc.go
@@ -15,6 +15,19 @@ const Tab = "\t"
 
 const hex = "0123456789abcdef"
 
+func hex2int[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
+	}
+}
+
 var (
 	numberType    = reflect.TypeOf(json.Number(""))
 	byteType      = reflect.TypeOf(byte(0))