part 'aperture_value.dart'; part 'iso_value.dart'; part 'shutter_speed_value.dart'; enum Stop { full, half, third } abstract class PhotographyValue { final T rawValue; final Stop stopType; const PhotographyValue(this.rawValue, this.stopType); T get value; } extension PhotographyValues on List { List whereStopType(Stop stopType) { switch (stopType) { case Stop.full: return where((e) => e.stopType == Stop.full).toList(); case Stop.half: return where((e) => e.stopType == Stop.full || e.stopType == Stop.half).toList(); case Stop.third: return where((e) => e.stopType == Stop.full || e.stopType == Stop.third).toList(); } } List fullStops() => whereStopType(Stop.full); List halfStops() => whereStopType(Stop.half); List thirdStops() => whereStopType(Stop.third); }