Add new Dart 2 Map methods to BiMap (#423)

google · Mar 23, 2018 · 8ad2873 · 8ad2873
1 parent 520ee76
commit 8ad2873
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Showing 3 changed files with 117 additions and 36 deletions.
diff --git a/CHANGELOG.md b/CHANGELOG.md
@@ -1,5 +1,7 @@
 #### Master
 
+   * New: BiMap now includes a real implementation of `addEntries`, `get
+     entries`, `map`, `removeWhere`, `update`, and `updateAll`.
    * New: DelegatingIterable now includes a real implementation of
      `followedBy`, and accepts the `orElse` parameter on `singleWhere`.
    * New: DelegatingList now includes real implementations of `operator +`,

diff --git a/lib/src/collection/bimap.dart b/lib/src/collection/bimap.dart
@@ -70,13 +70,13 @@ class HashBiMap<K, V> implements BiMap<K, V> {
   int get length => _map.length;
   Iterable<V> get values => _inverse.keys;
 
+  BiMap<V, K> get inverse => _cached ??= new HashBiMap._from(_inverse, _map);
+
   @override
-  // TODO: Dart 2.0 requires this method to be implemented.
-  // ignore: override_on_non_overriding_method
-  void addEntries(Iterable<Object> entries) {
-    // Change Iterable<Object> to Iterable<MapEntry<K, V>> when
-    // the MapEntry class has been added.
-    throw new UnimplementedError("addEntries");
+  void addEntries(Iterable<MapEntry<K, V>> entries) {
+    for (var entry in entries) {
+      _add(entry.key, entry.value, false);
+    }
   }
 
   @override
@@ -87,29 +87,11 @@ class HashBiMap<K, V> implements BiMap<K, V> {
   }
 
   @override
-  // TODO: Dart 2.0 requires this method to be implemented.
-  // ignore: override_on_non_overriding_getter
-  Iterable<Null> get entries {
-    // Change Iterable<Null> to Iterable<MapEntry<K, V>> when
-    // the MapEntry class has been added.
-    throw new UnimplementedError("entries");
-  }
-
-  BiMap<V, K> get inverse {
-    if (_cached == null) {
-      _cached = new HashBiMap._from(_inverse, _map);
-    }
-    return _cached;
-  }
+  Iterable<MapEntry<K, V>> get entries => _map.entries;
 
   @override
-  // TODO: Dart 2.0 requires this method to be implemented.
-  // ignore: override_on_non_overriding_method
-  Map<K2, V2> map<K2, V2>(Object transform(K key, V value)) {
-    // Change Object to MapEntry<K2, V2> when
-    // the MapEntry class has been added.
-    throw new UnimplementedError("map");
-  }
+  Map<K2, V2> map<K2, V2>(MapEntry<K2, V2> transform(K key, V value)) =>
+      _map.map(transform);
 
   V putIfAbsent(K key, V ifAbsent()) {
     var value = _map[key];
@@ -124,10 +106,9 @@ class HashBiMap<K, V> implements BiMap<K, V> {
   }
 
   @override
-  // TODO: Dart 2.0 requires this method to be implemented.
-  // ignore: override_on_non_overriding_method
   void removeWhere(bool test(K key, V value)) {
-    throw new UnimplementedError("removeWhere");
+    _inverse.removeWhere((v, k) => test(k, v));
+    _map.removeWhere(test);
   }
 
   @override
@@ -138,17 +119,22 @@ class HashBiMap<K, V> implements BiMap<K, V> {
   }
 
   @override
-  // TODO: Dart 2.0 requires this method to be implemented.
-  // ignore: override_on_non_overriding_method
   V update(K key, V update(V value), {V ifAbsent()}) {
-    throw new UnimplementedError("update");
+    var value = _map[key];
+    if (value != null) {
+      return _add(key, update(value), true);
+    } else {
+      if (ifAbsent == null)
+        throw new ArgumentError.value(key, 'key', 'Key not in map');
+      return _add(key, ifAbsent(), false);
+    }
   }
 
   @override
-  // TODO: Dart 2.0 requires this method to be implemented.
-  // ignore: override_on_non_overriding_method
   void updateAll(V update(K key, V value)) {
-    throw new UnimplementedError("updateAll");
+    for (var key in this.keys) {
+      _add(key, update(key, _map[key]), true);
+    }
   }
 
   void clear() {

diff --git a/test/collection/bimap_test.dart b/test/collection/bimap_test.dart
@@ -161,13 +161,63 @@ main() {
       map.remove(k1);
       expect(map.containsKey(k1), false);
       expect(map.inverse.containsKey(v1), false);
+
+      map[k1] = v1;
+      map[k2] = v2;
+      map.removeWhere((k, v) => v.isOdd);
+      expect(map.containsKey(k1), false);
+      expect(map.containsKey(k2), true);
+      expect(map.inverse.containsKey(v1), false);
+      expect(map.inverse.containsKey(v2), true);
     });
 
     test('should not contain mappings removed from its inverse', () {
       map[k1] = v1;
       map.inverse.remove(v1);
       expect(map.containsKey(k1), false);
       expect(map.inverse.containsKey(v1), false);
+
+      map[k1] = v1;
+      map[k2] = v2;
+      map.inverse.removeWhere((v, k) => v.isOdd);
+      expect(map.containsKey(k1), false);
+      expect(map.containsKey(k2), true);
+      expect(map.inverse.containsKey(v1), false);
+      expect(map.inverse.containsKey(v2), true);
+    });
+
+    test('should update both sides', () {
+      map[k1] = v1;
+      map.update(k1, (v) => v + 1);
+      expect(map[k1], equals(v1 + 1));
+      expect(map.inverse[v1 + 1], equals(k1));
+
+      map[k1] = v1;
+      map.inverse.update(v1, (k) => '_$k');
+      expect(map['_$k1'], equals(v1));
+      expect(map.inverse[v1], equals('_$k1'));
+    });
+
+    test('should update absent key values', () {
+      map[k1] = v1;
+      map.update(k2, (v) => v + 1, ifAbsent: () => 0);
+      expect(map[k2], equals(0));
+      expect(map.inverse[0], equals(k2));
+
+      map[k1] = v1;
+      map.inverse.update(v2, (k) => '_$k', ifAbsent: () => '_X');
+      expect(map['_X'], equals(v2));
+      expect(map.inverse[v2], equals('_X'));
+    });
+
+    test('should update all values', () {
+      map[k1] = v1;
+      map[k2] = v2;
+      map.updateAll((k, v) => v + k.length);
+      expect(map[k1], equals(3));
+      expect(map[k2], equals(4));
+      expect(map.inverse[3], equals(k1));
+      expect(map.inverse[4], equals(k2));
     });
 
     test('should be empty after clear', () {
@@ -230,6 +280,49 @@ main() {
       expect(map.inverse.values, unorderedEquals([k1, k2]));
     });
 
+    test('should add entries', () {
+      map.addEntries([new MapEntry<String, int>(k1, v1)]);
+      expect(map[k1], equals(v1));
+      expect(map.inverse[v1], equals(k1));
+
+      map.inverse.addEntries([new MapEntry<int, String>(v2, k2)]);
+      expect(map[k2], equals(v2));
+      expect(map.inverse[v2], equals(k2));
+    });
+
+    test('should get entries', () {
+      map[k1] = v1;
+      map.inverse[v2] = k2;
+
+      var mapEntries = map.entries;
+      expect(mapEntries, hasLength(2));
+      // MapEntry objects are not equal to each other; cannot use `contains`. :(
+      expect(mapEntries.singleWhere((e) => e.key == k1).value, equals(v1));
+      expect(mapEntries.singleWhere((e) => e.key == k2).value, equals(v2));
+
+      var inverseEntries = map.inverse.entries;
+      expect(inverseEntries, hasLength(2));
+      expect(inverseEntries.singleWhere((e) => e.key == v1).value, equals(k1));
+      expect(inverseEntries.singleWhere((e) => e.key == v2).value, equals(k2));
+    });
+
+    test('should map mappings', () {
+      map[k1] = v1;
+      map[k2] = v2;
+
+      var mapped = map.map((k, v) => new MapEntry(k.toUpperCase(), '$k / $v'));
+      expect(mapped, contains('K1'));
+      expect(mapped, contains('K2'));
+      expect(mapped['K1'], equals('k1 / 1'));
+      expect(mapped['K2'], equals('k2 / 2'));
+
+      var mapped2 = map.inverse.map((v, k) => new MapEntry('$v$v', k.length));
+      expect(mapped2, contains('11'));
+      expect(mapped2, contains('22'));
+      expect(mapped2['11'], equals(2));
+      expect(mapped2['22'], equals(2));
+    });
+
     test('should add mappings via putIfAbsent if absent', () {
       map.putIfAbsent(k1, () => v1);
       expect(map[k1], v1);