Maybe use bitwise check in your engine?

[Plague Fox]

Maybe use bitwise check?

void main() {
  const limit = 10000000;
  final stopwatch = Stopwatch()..start();
  for (var i = -limit; i <= limit; i++) {
    if (i.isEven == i.isOdd) {
      throw Exception('OOOOOPS');
    }
  }
  print('SDK: ${stopwatch.elapsedMilliseconds} ms');
  stopwatch.reset();
  for (var i = -limit; i <= limit; i++) {
    if (i.isEvenBitwise == i.isOddBitwise) {
      throw Exception('OOOOOPS');
    }
  }
  print('Bitwise: ${stopwatch.elapsedMilliseconds} ms');
  stopwatch.reset();
  for (var i = -limit; i <= limit; i++) {
    if (i.isEvenDivision == i.isOddDivision) {
      throw Exception('OOOOOPS');
    }
  }
  print('Division: ${stopwatch.elapsedMilliseconds} ms');
  stopwatch.stop();
}

extension on int {
  /// n ^ 1 is n + 1, then even
  bool get isEvenBitwise => abs() ^ 1 == abs() + 1;

  // n ^ 1 is not n + 1, then odd
  bool get isOddBitwise => abs() ^ 1 != abs() + 1;

  /// n % 2 is 0, then even
  bool get isEvenDivision => this % 2 == 0;

  // n % 2 is not 0, then odd
  bool get isOddDivision => this % 2 != 0;
}

[Plague Fox]

@arnemolland check with division is extra slow, about two times, we must use abs() ^ 1 != abs() + 1; to check isOdd

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