Move toString() to collection classes.

sdk/lib/_collection_dev/iterable.dart

Index: sdk/lib/_collection_dev/iterable.dart
diff --git a/sdk/lib/_collection_dev/iterable.dart b/sdk/lib/_collection_dev/iterable.dart
index 6e1e5ecb7c1b79be349de5fd215359d8294a6b0e..51d069accb4e08c3859238dbd20d7d6a9a687453 100644
--- a/sdk/lib/_collection_dev/iterable.dart
+++ b/sdk/lib/_collection_dev/iterable.dart
@@ -702,6 +702,9 @@ abstract class BidirectionalIterator<T> implements Iterator<T> {
  * The uses of this class will be replaced by mixins.
  */
 class IterableMixinWorkaround {
+  // A list to identify cyclic collections during toString() calls. 
+  static List _toStringList = new List();
+  
   static bool contains(Iterable iterable, var element) {
     for (final e in iterable) {
       if (e == element) return true;
@@ -895,6 +898,44 @@ class IterableMixinWorkaround {
     return buffer.toString();
   }
 
+  static String toStringIterable(Iterable iterable) {
+    for (int i = 0; i < _toStringList.length; i++) {
+      if (identical(_toStringList[i], iterable)) { return '{...}'; }
+    }
+    
+    StringBuffer result = new StringBuffer();
+    try {
+      _toStringList.add(iterable);
+      result.write('{');
+      result.writeAll(iterable, ', ');
+      result.write('}');
+    } finally {
+      assert(identical(_toStringList.last, iterable));
+      _toStringList.removeLast();
+      

[Lasse Reichstein Nielsen, 2013/07/09 06:15:44]

Empty line added. Seems inconsistent. Consider removing it.

[zarah, 2013/07/09 08:20:54]

Done.

+    }
+    return result.toString();      
+  }
+  
+  static String toStringList(List list) {
+    for (int i = 0; i < _toStringList.length; i++) {
+      if (identical(_toStringList[i], list)) { return '[...]'; }
+    }
+
+    StringBuffer result = new StringBuffer();
+    try {
+      _toStringList.add(list);
+      result.write('[');
+      result.writeAll(list, ', ');
+      result.write(']');
+     } finally {
+       assert(identical(_toStringList.last, list));
+       _toStringList.removeLast();  
+     }
+     
+    return result.toString();
+  }

[Lasse Reichstein Nielsen, 2013/07/09 06:15:44]

These two methods look almost, but not entirely, completely the same.
Would it be worth having a third method that takes delimiters as arguments as
well, and call it with either "{" amd "}", or with "[" and "]" for lists.

Alternatively, consider iterating the list using an index and see if you save
anything by not creating the iterator in writeAll.

[zarah, 2013/07/09 08:20:54]

Done.

+
   static Iterable where(Iterable iterable, bool f(var element)) {
     return new WhereIterable(iterable, f);
   }