diff --git a/regex/matching.go b/regex/matching.go
index faf56a5..879585d 100644
--- a/regex/matching.go
+++ b/regex/matching.go
@@ -350,7 +350,7 @@ func (re Reg) Expand(dst string, template string, src string, match Match) strin
 				i++
 			} else {
 				numStr := ""
-				for unicode.IsDigit(templateRuneSlc[i]) {
+				for i < len(templateRuneSlc) && unicode.IsDigit(templateRuneSlc[i]) {
 					numStr += string(templateRuneSlc[i])
 					i++
 				}
@@ -395,3 +395,23 @@ func (re Reg) LiteralPrefix() (prefix string, complete bool) {
 	}
 	return prefix, complete
 }
+
+// ReplaceAll replaces all matches of the expression in src, with the text in repl. In repl, variables are interpreted
+// as they are in [Reg.Expand]. The resulting string is returned.
+func (re Reg) ReplaceAll(src string, repl string) string {
+	matches := re.FindAllSubmatch(src)
+	i := 0
+	currentMatch := 0
+	dst := ""
+	for i < len(src) {
+		if currentMatch <= len(matches) && matches[currentMatch][0].IsValid() && i == matches[currentMatch][0].StartIdx {
+			dst += re.Expand("", repl, src, matches[currentMatch])
+			i = matches[currentMatch][0].EndIdx
+			currentMatch++
+		} else {
+			dst += string(src[i])
+			i++
+		}
+	}
+	return dst
+}