Remove Maps; move _fillMapWith* methods to MapBase

Fixes #31843

Bug: https://github.com/dart-lang/sdk/issues/31843
Change-Id: I02c544c921951f4a50421205dc1f25997cbecd6e
Reviewed-on: https://dart-review.googlesource.com/39880
Commit-Queue: Samuel Rawlins <srawlins@google.com>
Reviewed-by: Lasse R.H. Nielsen <lrn@google.com>

CHANGELOG.md

@@ -6,6 +6,10 @@
 
 ### Core library changes
 
+* `dart:collection`
+  * Removed `Maps` class. Extend `MapBase` or mix in `MapMixin` instead to
+    provide map method implementations for a class.
+
 ### Tool Changes
 
 ## 2.0.0-dev.42.0

sdk/lib/_internal/js_runtime/lib/convert_patch.dart

@@ -8,7 +8,7 @@ import 'dart:_js_helper' show argumentErrorValue, patch;
 import 'dart:_foreign_helper' show JS;
 import 'dart:_interceptors' show JSExtendableArray;
 import 'dart:_internal' show MappedIterable, ListIterable;
-import 'dart:collection' show Maps, LinkedHashMap, MapBase;
+import 'dart:collection' show LinkedHashMap, MapBase;
 import 'dart:_native_typed_data' show NativeUint8List;
 
 /**

sdk/lib/collection/hash_map.dart

@@ -133,7 +133,7 @@ abstract class HashMap<K, V> implements Map<K, V> {
   factory HashMap.fromIterable(Iterable iterable,
       {K key(element), V value(element)}) {
     Map<K, V> map = new HashMap<K, V>();
-    Maps._fillMapWithMappedIterable(map, iterable, key, value);
+    MapBase._fillMapWithMappedIterable(map, iterable, key, value);
     return map;
   }
 
@@ -150,7 +150,7 @@ abstract class HashMap<K, V> implements Map<K, V> {
    */
   factory HashMap.fromIterables(Iterable<K> keys, Iterable<V> values) {
     Map<K, V> map = new HashMap<K, V>();
-    Maps._fillMapWithIterables(map, keys, values);
+    MapBase._fillMapWithIterables(map, keys, values);
     return map;
   }
 }

sdk/lib/collection/linked_hash_map.dart

@@ -121,7 +121,7 @@ abstract class LinkedHashMap<K, V> implements Map<K, V> {
   factory LinkedHashMap.fromIterable(Iterable iterable,
       {K key(element), V value(element)}) {
     LinkedHashMap<K, V> map = new LinkedHashMap<K, V>();
-    Maps._fillMapWithMappedIterable(map, iterable, key, value);
+    MapBase._fillMapWithMappedIterable(map, iterable, key, value);
     return map;
   }
 
@@ -138,7 +138,7 @@ abstract class LinkedHashMap<K, V> implements Map<K, V> {
    */
   factory LinkedHashMap.fromIterables(Iterable<K> keys, Iterable<V> values) {
     LinkedHashMap<K, V> map = new LinkedHashMap<K, V>();
-    Maps._fillMapWithIterables(map, keys, values);
+    MapBase._fillMapWithIterables(map, keys, values);
     return map;
   }
 }

sdk/lib/collection/maps.dart

@@ -49,6 +49,48 @@ abstract class MapBase<K, V> extends MapMixin<K, V> {
 
     return result.toString();
   }
+
+  static _id(x) => x;
+
+  /**
+   * Fills a [Map] with key/value pairs computed from [iterable].
+   *
+   * This method is used by [Map] classes in the named constructor
+   * `fromIterable`.
+   */
+  static void _fillMapWithMappedIterable(
+      Map map, Iterable iterable, key(element), value(element)) {
+    key ??= _id;
+    value ??= _id;
+
+    for (var element in iterable) {
+      map[key(element)] = value(element);
+    }
+  }
+
+  /**
+   * Fills a map by associating the [keys] to [values].
+   *
+   * This method is used by [Map] classes in the named constructor
+   * `fromIterables`.
+   */
+  static void _fillMapWithIterables(Map map, Iterable keys, Iterable values) {
+    Iterator keyIterator = keys.iterator;
+    Iterator valueIterator = values.iterator;
+
+    bool hasNextKey = keyIterator.moveNext();
+    bool hasNextValue = valueIterator.moveNext();
+
+    while (hasNextKey && hasNextValue) {
+      map[keyIterator.current] = valueIterator.current;
+      hasNextKey = keyIterator.moveNext();
+      hasNextValue = valueIterator.moveNext();
+    }
+
+    if (hasNextKey || hasNextValue) {
+      throw new ArgumentError("Iterables do not have same length.");
+    }
+  }
 }
 
 /**
@@ -347,109 +389,3 @@ class UnmodifiableMapView<K, V> extends MapView<K, V>
   Map<RK, RV> retype<RK, RV>() =>
       new UnmodifiableMapView<RK, RV>(_map.retype<RK, RV>());
 }
-
-/**
- * Helper class which implements complex [Map] operations
- * in term of basic ones ([Map.keys], [Map.[]],
- * [Map.[]=] and [Map.remove].)  Not all methods are
- * necessary to implement each particular operation.
- *
- * Deprecated. Will be removed in Dart 2.
- */
-class Maps {
-  static bool containsValue(Map map, Object value) {
-    for (final v in map.values) {
-      if (v == value) {
-        return true;
-      }
-    }
-    return false;
-  }
-
-  static bool containsKey(Map map, Object key) {
-    for (final k in map.keys) {
-      if (k == key) {
-        return true;
-      }
-    }
-    return false;
-  }
-
-  static putIfAbsent(Map map, key, ifAbsent()) {
-    if (map.containsKey(key)) {
-      return map[key];
-    }
-    final v = ifAbsent();
-    map[key] = v;
-    return v;
-  }
-
-  static clear(Map map) {
-    for (final k in map.keys.toList()) {
-      map.remove(k);
-    }
-  }
-
-  static forEach(Map map, void f(key, value)) {
-    for (final k in map.keys) {
-      f(k, map[k]);
-    }
-  }
-
-  static Iterable getValues(Map map) {
-    return map.keys.map((key) => map[key]);
-  }
-
-  static int length(Map map) => map.keys.length;
-
-  static bool isEmpty(Map map) => map.keys.isEmpty;
-
-  static bool isNotEmpty(Map map) => map.keys.isNotEmpty;
-
-  /**
-   * Do not use. This entire class will be removed.
-   *
-   * Use [MapBase.mapToString] instead.
-   */
-  static String mapToString(Map m) => MapBase.mapToString(m);
-
-  static _id(x) => x;
-
-  /**
-   * Fills a map with key/value pairs computed from [iterable].
-   *
-   * This method is used by Map classes in the named constructor fromIterable.
-   */
-  static void _fillMapWithMappedIterable(
-      Map map, Iterable iterable, key(element), value(element)) {
-    if (key == null) key = _id;
-    if (value == null) value = _id;
-
-    for (var element in iterable) {
-      map[key(element)] = value(element);
-    }
-  }
-
-  /**
-   * Fills a map by associating the [keys] to [values].
-   *
-   * This method is used by Map classes in the named constructor fromIterables.
-   */
-  static void _fillMapWithIterables(Map map, Iterable keys, Iterable values) {
-    Iterator keyIterator = keys.iterator;
-    Iterator valueIterator = values.iterator;
-
-    bool hasNextKey = keyIterator.moveNext();
-    bool hasNextValue = valueIterator.moveNext();
-
-    while (hasNextKey && hasNextValue) {
-      map[keyIterator.current] = valueIterator.current;
-      hasNextKey = keyIterator.moveNext();
-      hasNextValue = valueIterator.moveNext();
-    }
-
-    if (hasNextKey || hasNextValue) {
-      throw new ArgumentError("Iterables do not have same length.");
-    }
-  }
-}

sdk/lib/collection/splay_tree.dart

@@ -334,7 +334,7 @@ class SplayTreeMap<K, V> extends _SplayTree<K, _SplayTreeMapNode<K, V>>
       int compare(K key1, K key2),
       bool isValidKey(potentialKey)}) {
     SplayTreeMap<K, V> map = new SplayTreeMap<K, V>(compare, isValidKey);
-    Maps._fillMapWithMappedIterable(map, iterable, key, value);
+    MapBase._fillMapWithMappedIterable(map, iterable, key, value);
     return map;
   }
 
@@ -352,7 +352,7 @@ class SplayTreeMap<K, V> extends _SplayTree<K, _SplayTreeMapNode<K, V>>
   factory SplayTreeMap.fromIterables(Iterable<K> keys, Iterable<V> values,
       [int compare(K key1, K key2), bool isValidKey(potentialKey)]) {
     SplayTreeMap<K, V> map = new SplayTreeMap<K, V>(compare, isValidKey);
-    Maps._fillMapWithIterables(map, keys, values);
+    MapBase._fillMapWithIterables(map, keys, values);
     return map;
   }
 

tests/co19/co19-dart2js.status

@@ -116,6 +116,7 @@ LibTest/collection/LinkedHashSet/LinkedHashSet.from_A03_t01: RuntimeError # Plea
 LibTest/collection/LinkedList/add_A01_t01: Pass, Slow # Slow tests that needs extra time to finish.
 LibTest/collection/ListBase/ListBase_class_A01_t01: RuntimeError # Please triage this failure
 LibTest/collection/ListMixin/ListMixin_class_A01_t01: RuntimeError # Please triage this failure
+LibTest/collection/Maps/*: Skip # Maps class no longer exists
 LibTest/convert/JsonCodec/encode_A01_t01: RuntimeError # code.google.com/p/co19/issues/detail?id=735
 LibTest/convert/JsonCodec/encode_A01_t02: RuntimeError # code.google.com/p/co19/issues/detail?id=735
 LibTest/convert/JsonDecoder/fuse_A01_t01: RuntimeError # co19-roll r667: Please triage this failure

tests/co19/co19-kernel.status

@@ -7,6 +7,7 @@ Language/Classes/definition_t24: MissingCompileTimeError
 Language/Types/Type_Void/syntax_t08: MissingCompileTimeError
 Language/Types/Type_Void/syntax_t09: MissingCompileTimeError
 LayoutTests/*: Skip # TODO(ahe): Make dart:html available.
+LibTest/collection/Maps/*: Skip # Maps class no longer exists.
 LibTest/html/*: Skip # TODO(ahe): Make dart:html available.
 WebPlatformTest/*: Skip # TODO(ahe): Make dart:html available.
 

tests/co19/co19-runtime.status

@@ -303,6 +303,7 @@ Language/Types/Type_Void/syntax_t09: MissingCompileTimeError # Issue co19/30264
 LayoutTests/fast/*: SkipByDesign # DOM not supported on VM.
 LibTest/collection/ListBase/ListBase_class_A01_t01: RuntimeError # Large integers
 LibTest/collection/ListMixin/ListMixin_class_A01_t01: RuntimeError # Large integers
+LibTest/collection/Maps/*: Skip # Maps class no longer exists
 LibTest/core/Duration/inDays_A01_t01: RuntimeError # Large integers
 LibTest/core/Duration/inHours_A01_t01: RuntimeError # Large integers
 LibTest/core/Duration/inMilliseconds_A01_t01: RuntimeError # Large integers

tests/corelib/corelib.status

@@ -2,6 +2,8 @@
 # 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.
 
+maps_test: Skip # Maps class no longer exists
+
 [ $compiler == dart2analyzer ]
 *: Skip
 

tests/corelib_2/corelib_2.status

@@ -3,6 +3,8 @@
 # BSD-style license that can be found in the LICENSE file.
 iterable_where_type_test: RuntimeError # Disabled.  Issue 32463
 
+maps_test: Skip # Maps class no longer exists
+
 [ $compiler == dart2analyzer ]
 bigint_from_test: CompileTimeError # Issue 32585
 compare_to2_test: CompileTimeError # invalid test