Change the static castTo methods to be named castFrom.

It's just a better name.

Bug:
Change-Id: I0bf42b53fb5041faa307d288ffe12fb4b1ac7068
Reviewed-on: https://dart-review.googlesource.com/34180
Reviewed-by: Leaf Petersen <leafp@google.com>

sdk/lib/collection/queue.dart

@@ -31,6 +31,23 @@ abstract class Queue<E> implements EfficientLengthIterable<E> {
    */
   factory Queue.from(Iterable elements) = ListQueue<E>.from;
 
+  /**
+   * Adapts [source] to be a `Queue<T>`.
+   *
+   * Any time the queue would produce an element that is not a [T],
+   * the element access will throw.
+   *
+   * Any time a [T] value is attempted stored into the adapted queue,
+   * the store will throw unless the value is also an instance of [S].
+   *
+   * If all accessed elements of [source] are actually instances of [T],
+   * and if all elements stored into the returned queue are actually instance
+   * of [S],
+   * then the returned queue can be used as a `Queue<T>`.
+   */
+  static Queue<T> castFrom<S, T>(Queue<S> source) =>
+      new CastQueue<S, T>(source);
+
   /**
    * Removes and returns the first element of this queue.
    *

sdk/lib/core/iterable.dart

@@ -118,7 +118,7 @@ abstract class Iterable<E> {
    * instances of [T], or if only elements that are actually instances of [T]
    * are accessed, then the resulting iterable can be used as an `Iterable<T>`.
    */
-  static Iterable<T> castTo<S, T>(Iterable<S> source) =>
+  static Iterable<T> castFrom<S, T>(Iterable<S> source) =>
       new CastIterable<S, T>(source);
 
   /**

sdk/lib/core/list.dart

@@ -169,7 +169,7 @@ abstract class List<E> implements EfficientLengthIterable<E> {
    * of [S],
    * then the returned list can be used as a `List<T>`.
    */
-  static List<T> castTo<S, T>(List<S> source) => new CastList<S, T>(source);
+  static List<T> castFrom<S, T>(List<S> source) => new CastList<S, T>(source);
 
   /**
    * Returns the object at the given [index] in the list

sdk/lib/core/map.dart

@@ -156,7 +156,7 @@ abstract class Map<K, V> {
    * and if all entries added to the returned map have [K] keys and [V]] values,
    * then the returned map can be used as a `Map<K2, V2>`.
    */
-  static Map<K2, V2> castTo<K, V, K2, V2>(Map<K, V> source) =>
+  static Map<K2, V2> castFrom<K, V, K2, V2>(Map<K, V> source) =>
       new CastMap<K, V, K2, V2>(source);
 
   /**

sdk/lib/core/set.dart

@@ -98,7 +98,7 @@ abstract class Set<E> extends EfficientLengthIterable<E> {
    * of [S],
    * then the returned set can be used as a `Set<T>`.
    */
-  static Set<T> castTo<S, T>(Set<S> source, {Set<R> Function<R>() newSet}) =>
+  static Set<T> castFrom<S, T>(Set<S> source, {Set<R> Function<R>() newSet}) =>
       new CastSet<S, T>(source, newSet);
 
   /**

tests/corelib_2/cast_test.dart

@@ -18,7 +18,7 @@ void testIterable() {
   // Down-cast
   {
     // An iterable that (likely) can do direct access.
-    var dIterable = Iterable.castTo<C, D>(iterable);
+    var dIterable = Iterable.castFrom<C, D>(iterable);
 
     Expect.throws(() => dIterable.first, null, "1.first");
     Expect.equals(d, dIterable.elementAt(1));
@@ -31,7 +31,7 @@ void testIterable() {
 
   {
     // An iterable that cannot do direct access.
-    var dIterable2 = Iterable.castTo<C, D>(iterable.where((_) => true));
+    var dIterable2 = Iterable.castFrom<C, D>(iterable.where((_) => true));
 
     Expect.throws(() => dIterable2.first, null, "2.first");
     Expect.equals(d, dIterable2.elementAt(1));
@@ -46,7 +46,7 @@ void testIterable() {
     // Iterable that definitely won't survive accessing element 2.
     var iterable3 = new Iterable<C>.generate(
         elements.length, (n) => n == 3 ? throw "untouchable" : elements[n]);
-    var dIterable3 = Iterable.castTo<C, D>(iterable3);
+    var dIterable3 = Iterable.castFrom<C, D>(iterable3);
 
     Expect.throws(() => dIterable3.first, null, "3.first");
     Expect.equals(d, dIterable3.elementAt(1));
@@ -60,7 +60,7 @@ void testIterable() {
 
   // Up-cast.
   {
-    var oIterable4 = Iterable.castTo<C, Object>(iterable);
+    var oIterable4 = Iterable.castFrom<C, Object>(iterable);
     Expect.listEquals(elements, oIterable4.toList());
   }
 }
@@ -68,7 +68,7 @@ void testIterable() {
 void testList() {
   // Down-cast.
   var list = new List<C>.from(elements);
-  var dList = List.castTo<C, D>(list);
+  var dList = List.castFrom<C, D>(list);
 
   Expect.throws(() => dList.first); // C is not D.
   Expect.equals(d, dList[1]);
@@ -83,7 +83,7 @@ void testList() {
 
   // Up-cast.
   var list2 = new List<C>.from(elements);
-  var dList2 = List.castTo<C, Object>(list2);
+  var dList2 = List.castFrom<C, Object>(list2);
   Expect.listEquals(elements, dList2);
   Expect.throws(() => dList2[2] = new Object()); // Cannot set non-C.
   Expect.listEquals(elements, dList2);
@@ -93,7 +93,7 @@ void testSet() {
   var set = new Set<C>.from(elements); // Linked HashSet.
   Expect.listEquals(elements, set.toList()); // Preserves order.
 
-  var dSet = Set.castTo<C, D>(set);
+  var dSet = Set.castFrom<C, D>(set);
 
   // Preserves order.
   Expect.throws(() => dSet.first); // C is not D.
@@ -116,7 +116,7 @@ void testSet() {
 
   // Up-cast
   var set2 = new Set<C>.from(elements);
-  var dSet2 = Set.castTo<C, Object>(set2);
+  var dSet2 = Set.castFrom<C, Object>(set2);
 
   var newObject = new Object();
   Expect.throws(() => dSet2.add(newObject));
@@ -129,7 +129,7 @@ void testSet() {
   // Custom emptySet.
 
   var set3 = new Set<C>.from(elements);
-  var dSet3 = Set.castTo<C, Object>(set3, newSet: <T>() => new HashSet<T>());
+  var dSet3 = Set.castFrom<C, Object>(set3, newSet: <T>() => new HashSet<T>());
 
   var toSet3 = dSet3.toSet();
   Expect.isTrue(toSet3 is HashSet<Object>);
@@ -140,7 +140,7 @@ void testSet() {
 void testMap() {
   var map = new Map.fromIterables(elements, elements);
 
-  var dMap = Map.castTo<C, C, D, D>(map);
+  var dMap = Map.castFrom<C, C, D, D>(map);
 
   Expect.isTrue(dMap is Map<D, D>);