| // Copyright (c) 2018, the Dart project authors. Please see the AUTHORS file |
| // for details. All rights reserved. Use of this source code is governed by a |
| // BSD-style license that can be found in the LICENSE file. |
| |
| import 'dart:collection'; |
| |
| import '../path.dart' as p; |
| |
| /// A map whose keys are paths, compared using [p.equals] and [p.hash]. |
| class PathMap<V> extends MapView<String?, V> { |
| /// Creates an empty [PathMap] whose keys are compared using `context.equals` |
| /// and `context.hash`. |
| /// |
| /// The [context] defaults to the current path context. |
| PathMap({p.Context? context}) : super(_create(context)); |
| |
| /// Creates a [PathMap] with the same keys and values as [other] whose keys |
| /// are compared using `context.equals` and `context.hash`. |
| /// |
| /// The [context] defaults to the current path context. If multiple keys in |
| /// [other] represent the same logical path, the last key's value will be |
| /// used. |
| PathMap.of(Map<String, V> other, {p.Context? context}) |
| : super(_create(context)..addAll(other)); |
| |
| /// Creates a map that uses [context] for equality and hashing. |
| static Map<String?, V> _create<V>(p.Context? context) { |
| context ??= p.context; |
| return LinkedHashMap( |
| equals: (path1, path2) { |
| if (path1 == null) return path2 == null; |
| if (path2 == null) return false; |
| return context!.equals(path1, path2); |
| }, |
| hashCode: (path) => path == null ? 0 : context!.hash(path), |
| isValidKey: (path) => path is String || path == null); |
| } |
| } |