Fixed toString of Platform.environment on Windows

sdk/lib/io/platform_impl.dart

Index: sdk/lib/io/platform_impl.dart
diff --git a/sdk/lib/io/platform_impl.dart b/sdk/lib/io/platform_impl.dart
index c6063a8c21265283f710ee427b0d959041586bc7..a7631275628111a73343badb51eaee4039a35317 100644
--- a/sdk/lib/io/platform_impl.dart
+++ b/sdk/lib/io/platform_impl.dart
@@ -71,7 +71,7 @@ class _Platform {
           result[str.substring(0, equalsIndex)] =
               str.substring(equalsIndex + 1);
         }
-        _environmentCache = new UnmodifiableMapView(result);
+        _environmentCache = new UnmodifiableMapView<String, String>(result);
       } else {
         _environmentCache = env;
       }
@@ -89,36 +89,20 @@ class _Platform {
 
 // Environment variables are case-insensitive on Windows. In order
 // to reflect that we use a case-insensitive string map on Windows.
-class _CaseInsensitiveStringMap<V> implements Map<String, V> {
-  Map<String, V> _map;
+class _CaseInsensitiveStringMap<V> extends MapMixin<String, V> {

[Lasse Reichstein Nielsen, 2014/06/07 12:49:40]

Extend MapBase instead of MapMixin.
It's silly to have both, but for consistency, we do.

+  final Map<String, V> _map = new Map<String, V>();
 
-  _CaseInsensitiveStringMap() : _map = new Map<String, V>();
-
-  _CaseInsensitiveStringMap.from(Map<String, V> other)
-      : _map = new Map<String, V>() {
-    other.forEach((String key, V value) {
-      _map[key.toUpperCase()] = value;
-    });
-  }
-
-  bool containsKey(String key) => _map.containsKey(key.toUpperCase());
-  bool containsValue(Object value) => _map.containsValue(value);
   V operator [](String key) => _map[key.toUpperCase()];
+
   void operator []=(String key, V value) {
     _map[key.toUpperCase()] = value;
   }
-  V putIfAbsent(String key, V ifAbsent()) {
-    _map.putIfAbsent(key.toUpperCase(), ifAbsent);
-  }
-  addAll(Map other) {
-    other.forEach((key, value) => this[key.toUpperCase()] = value);
-  }
+
   V remove(String key) => _map.remove(key.toUpperCase());

[Lasse Reichstein Nielsen, 2014/06/07 12:49:41]

Remove should take an Object as argument, and just return null if it's not a
String.

+
   void clear() => _map.clear();
-  void forEach(void f(String key, V value)) => _map.forEach(f);
+
   Iterable<String> get keys => _map.keys;
-  Iterable<V> get values => _map.values;
-  int get length => _map.length;
-  bool get isEmpty => _map.isEmpty;
-  bool get isNotEmpty => _map.isNotEmpty;
+
+  String toString() => _map.toString();
 }

[Lasse Reichstein Nielsen, 2014/06/09 09:55:20]

If all of this is to just have a better toString, I would just add:

    String toString() => _map.toString();

Delegating to the underlying map is much better than having an extra map
implementation on top of a map.

We could then argue that DelegatingMap should be in dart:collection too, instead
of package:collection. It's like every useful feature we think of putting into a
package, we also start wanting in the core libraries. Can't have it all :(