Reapply 'Add reduce to Collection.'

Reapply 'Add reduce to Collection.'

Implemented JS array's reduce and fix a template error that made snapshotting crash.

BUG=
TEST=

Review URL: https://chromiumcodereview.appspot.com//10832060

git-svn-id: https://dart.googlecode.com/svn/branches/bleeding_edge/dart@10548 260f80e4-7a28-3924-810f-c04153c831b5

Committed: https://code.google.com/p/dart/source/detail?r=10557

[Anders Johnsen, 2012-08-13 09:19:42]

TBR

[Ivan Posva, 2012-08-13 16:58:45]

https://chromiumcodereview.appspot.com/10827293/diff/3001/tests/corelib/colle...
File tests/corelib/collection_test.dart (right):

https://chromiumcodereview.appspot.com/10827293/diff/3001/tests/corelib/colle...
tests/corelib/collection_test.dart:5: class CollectionTest {
To me it feels like this file will explode as you add more things in two
dimensions to be tested (features x implementations).

[Anders Johnsen, 2012-08-14 05:38:27]

https://chromiumcodereview.appspot.com/10827293/diff/3001/tests/corelib/colle...
File tests/corelib/collection_test.dart (right):

https://chromiumcodereview.appspot.com/10827293/diff/3001/tests/corelib/colle...
tests/corelib/collection_test.dart:5: class CollectionTest {
On 2012/08/13 16:58:45, Ivan Posva wrote:
> To me it feels like this file will explode as you add more things in two
> dimensions to be tested (features x implementations).

I agree that we test two dimensions, but we only have to spell out X and Y's,
not every x * y combinations. Is it too much to have x + y entries here?

[Lasse Reichstein Nielsen, 2012-08-14 09:00:07]

LGTM

https://chromiumcodereview.appspot.com/10827293/diff/3001/tests/corelib/colle...
File tests/corelib/collection_test.dart (right):

https://chromiumcodereview.appspot.com/10827293/diff/3001/tests/corelib/colle...
tests/corelib/collection_test.dart:5: class CollectionTest {
I think this is fine. I prefer a templated test to a lot of individual tests
that may or may not cover the same ground.

And yes, you get a lot of tests if you overdo it, as with anything, but this is
far from there yet.

https://chromiumcodereview.appspot.com/10827293/diff/3001/tests/corelib/colle...
tests/corelib/collection_test.dart:35: }
BTW, you might want to make a test with zero elements and with one element in
the collection as well.

[Ivan Posva, 2012-08-30 00:24:42]

DBC -ip

https://chromiumcodereview.appspot.com/10827293/diff/3001/runtime/lib/array.dart
File runtime/lib/array.dart (right):

https://chromiumcodereview.appspot.com/10827293/diff/3001/runtime/lib/array.d...
runtime/lib/array.dart:91: Dynamic reduce(Dynamic initialValue,
"Using Dynamic as type is bad style."™

Srdjan is fixing it.