extKEEPCHARS function

dynamic extKEEPCHARS(
  1. dynamic v1,
  2. dynamic v2
)

KEEPCHARS(str, chars): keeps only the given set of characters

Implementation

dynamic extKEEPCHARS(dynamic v1, dynamic v2) {
  final chars = varToStr(v2);
  return varToStr(v1).split("").where((c) => chars.contains(c)).join();
}