Added more tests

src/token/List.go

@@ -31,6 +31,10 @@ func (list List) LastIndexKind(kind Kind) int {
 
 // Split calls the callback function on each set of tokens in a comma separated list.
 func (list List) Split(call func(List) error) error {
+	if len(list) == 0 {
+		return nil
+	}
+
 	start := 0
 	groupLevel := 0
 
@@ -58,12 +62,8 @@ func (list List) Split(call func(List) error) error {
 		}
 	}
 
-	if start != len(list) {
-		parameter := list[start:]
-		return call(parameter)
-	}
-
-	return nil
+	parameter := list[start:]
+	return call(parameter)
 }
 
 // Text returns the concatenated token text.