class Allergies {
  static const List<String> _allergies = [
    'eggs',
    'peanuts',
    'shellfish',
    'strawberries',
    'tomatoes',
    'chocolate',
    'pollen',
    'cats',
  ];

  bool allergicTo(final String item, final int allergyScore) =>
      ((allergyScore >> _allergies.indexOf(item)) & 1) == 1;

  List<String> list(final int allergyScore) =>
      _allergies.where((allergy) => allergicTo(allergy, allergyScore)).toList();
}