Add reduce to Collection.

corelib/src/implementation/collections.dart

Index: corelib/src/implementation/collections.dart
diff --git a/corelib/src/implementation/collections.dart b/corelib/src/implementation/collections.dart
index 462d33af2a703382ecf34f320b5b8d8ca1a0913a..9ea332443653b5ec10979bd35fa72c5b15b0bf51 100644
--- a/corelib/src/implementation/collections.dart
+++ b/corelib/src/implementation/collections.dart
@@ -35,6 +35,13 @@ class Collections {
     return destination;
   }
 
+  static reduce(Iterable iterable, var init, f(prev, element)) {

[Lasse Reichstein Nielsen, 2012/08/08 07:19:14]

Add return value, even if it's just Object. It differentiates it from a "void"
return type.
Also add "var" in front of "prev" and "element" and don't abbreviate variables
nemes.

[Anders Johnsen, 2012/08/08 07:56:14]

Adding var does not provide any further information and is orthogonal to the
rest of the lib. The only reason to provide it in the Collection interface is to
show that prev and element is typed differently. We don't have that type
information here.

[Lasse Reichstein Nielsen, 2012/08/10 11:26:56]

Accepted, but not liked.
I prefer being explicit about what is expected. It differentiates a deliberate
choice from an accidental omission.

+    for (final e in iterable) {

[Lasse Reichstein Nielsen, 2012/08/08 07:19:14]

Yes, that means using 'element' instead of 'e'. It won't hurt.

[Anders Johnsen, 2012/08/08 07:56:14]

It's using the style from the rest of the file/lib. If we want to style it
differently, we should consider doing it to the hole file/lib.

[Lasse Reichstein Nielsen, 2012/08/10 11:26:56]

We do. We shoud. Please start here :)

[Anders Johnsen, 2012/11/12 12:02:56]

Done.

+      init = f(init, e);
+    }
+    return init;
+  }
+
   static List filter(Iterable source, List destination, bool f(o)) {
     for (final e in source) {
       if (f(e)) destination.add(e);