import 'dart:math' as math; import 'package:collection/collection.dart'; import 'package:nc_photos/int_extension.dart'; extension ListExtension on List { Iterable takeIndex(List indexes) => indexes.map((e) => this[e]); List slice(int start, [int? stop, int step = 1]) { assert(step > 0); if (start < 0) { start = math.max(length + start, 0); } if (stop != null && stop < 0) { stop = math.max(length + stop, 0); } if (start >= length) { return []; } else if (stop == null) { final sub = sublist(start); if (step <= 1) { return sub; } else { return sub.whereIndexed((index, _) => index % step == 0).toList(); } } else if (start >= stop) { return []; } else { final sub = sublist(start, math.min(stop, length)); if (step <= 1) { return sub; } else { return sub.whereIndexed((index, _) => index % step == 0).toList(); } } } void stableSort([int Function(T a, T b)? compare]) { mergeSort(this, compare: compare); } /// In-place transform and return this /// /// Since the elements are in-place transformed, they have to share the same /// type List transform(T Function(T element) fn) { for (final i in 0.until(length)) { this[i] = fn(this[i]); } return this; } Future> asyncMap(Future Function(T element) fn) { return Stream.fromIterable(this).asyncMap(fn).toList(); } }