Change List/Set/Map/Queue.from constructrs to accept any iterable.

sdk/lib/collection/hash_map.dart

Index: sdk/lib/collection/hash_map.dart
diff --git a/sdk/lib/collection/hash_map.dart b/sdk/lib/collection/hash_map.dart
index 720403104240f9b1f2aacb0b37dc6ae204ab3b4d..e67fa77556fc9a1d531dd39824e2ea8506922692 100644
--- a/sdk/lib/collection/hash_map.dart
+++ b/sdk/lib/collection/hash_map.dart
@@ -80,10 +80,12 @@ abstract class HashMap<K, V> implements Map<K, V> {
   external factory HashMap.identity();
 
   /**
-   * Creates a [HashMap] that contains all key value pairs of [other].
+   * Creates a [HashMap] that contains all key/value pairs of [other].
    */
-  factory HashMap.from(Map<K, V> other) {
-    return new HashMap<K, V>()..addAll(other);
+  factory HashMap.from(Map other) {
+    HashMap<K, V> result = new HashMap<K, V>();
+    other.forEach((k, v) { result[k] = v; });

[Søren Gjesse, 2015/01/05 15:35:15]

Add types K and V?

[Lasse Reichstein Nielsen, 2015/01/06 10:14:45]

The forEach method has type (K',V')->void where other:Map<K',V'>.
A (K,V)->void function might not be assignable to (K',V')->void, even if all the
keys and values of `other` happens to be K/V.

Example:
 class C {}
 class I {}
 class D extends C implements I {}
 Map<C,C> foo = ...;
 if (c.keys.every((v) => v is I) && c.values.every((v) => v is I)) {
   new Map<I,I>.from(foo);
 }

But it's tempting, so I'll add a test to catch it if someone decides to add K
and V later.

[Søren Gjesse, 2015/01/06 12:09:05]

Of cause.

+    return result;
   }
 
   /**