looksNumeric method

Implementation

bool looksNumeric() {
  if ( kind == 2 ) {
    return true;
  }
  if ( kind != 3 ) {
    return false;
  }
  if ( str.length == 0 ) {
    return false;
  }
  double? d = double.tryParse(str);
  if ( d != null ) {
    return true;
  }
  return false;
}