Added function and examples for ReplaceAllFunc()

regex/matching.go

@@ -428,6 +428,7 @@ func (re Reg) ReplaceAllLiteral(src string, repl string) string {
 		if currentMatch < len(zerogroups) && i == zerogroups[currentMatch].StartIdx {
 			dst += repl
 			i = zerogroups[currentMatch].EndIdx
+			currentMatch += 1
 		} else {
 			dst += string(src[i])
 			i++
@@ -435,3 +436,25 @@ func (re Reg) ReplaceAllLiteral(src string, repl string) string {
 	}
 	return dst
 }
+
+// ReplaceAllFunc replaces every match of the expression in src, with the return value of the function replFunc.
+// replFunc takes in the matched string. The return value is substituted in directly without expasion.
+func (re Reg) ReplaceAllFunc(src string, replFunc func(string) string) string {
+	zerogroups := re.FindAll(src)
+	currentMatch := 0
+	i := 0
+	dst := ""
+
+	for i < len(src) {
+		if currentMatch < len(zerogroups) && i == zerogroups[currentMatch].StartIdx {
+			dst += replFunc(src[zerogroups[currentMatch].StartIdx:zerogroups[currentMatch].EndIdx])
+			i = zerogroups[currentMatch].EndIdx
+			currentMatch += 1
+		} else {
+			dst += string(src[i])
+			i++
+		}
+	}
+	return dst
+
+}