isCustomIdent static method

Implementation

static bool isCustomIdent(String token) {
  if (token.isEmpty) return false;
  final String lower = token.toLowerCase();
  if (lower == 'auto' || lower == 'span') return false;
  int i = 0;
  if (token.codeUnitAt(0) == 0x2D /* - */) {
    i++;
    if (i >= token.length) return false;
  }
  final int first = token.codeUnitAt(i);
  final bool firstOk = first == 0x5F /* _ */ ||
      (first >= 0x41 && first <= 0x5A) ||
      (first >= 0x61 && first <= 0x7A);
  if (!firstOk) return false;
  for (i = i + 1; i < token.length; i++) {
    final int cu = token.codeUnitAt(i);
    final bool ok = cu == 0x5F /* _ */ ||
        cu == 0x2D /* - */ ||
        (cu >= 0x30 && cu <= 0x39) ||
        (cu >= 0x41 && cu <= 0x5A) ||
        (cu >= 0x61 && cu <= 0x7A);
    if (!ok) return false;
  }
  return true;
}