Added a new matcher for pairwise comparison of iterables with a custom comparator.

Added a new matcher for pairwise comparison of iterables with a custom comparator.

R=jmesserly@google.com, sigmund@google.com

Committed: https://code.google.com/p/dart/source/detail?r=22519

[Jennifer Messerly, 2013-05-08 00:16:25]

lgtm

https://codereview.chromium.org/15017013/diff/1/pkg/unittest/lib/src/iterable...
File pkg/unittest/lib/src/iterable_matchers.dart (right):

https://codereview.chromium.org/15017013/diff/1/pkg/unittest/lib/src/iterable...
pkg/unittest/lib/src/iterable_matchers.dart:199: Iterable _expected;
final?

https://codereview.chromium.org/15017013/diff/1/pkg/unittest/lib/src/iterable...
pkg/unittest/lib/src/iterable_matchers.dart:209: var e = _expected.elementAt(i);
any concern about the O(N^2) if this is a genuine iterable? I wonder if it's
better to convert to List first.

[gram, 2013-05-08 00:20:46]

On 2013/05/08 00:16:25, John Messerly wrote:
> lgtm
> 
>
https://codereview.chromium.org/15017013/diff/1/pkg/unittest/lib/src/iterable...
> File pkg/unittest/lib/src/iterable_matchers.dart (right):
> 
>
https://codereview.chromium.org/15017013/diff/1/pkg/unittest/lib/src/iterable...
> pkg/unittest/lib/src/iterable_matchers.dart:199: Iterable _expected;
> final?
> 
>
https://codereview.chromium.org/15017013/diff/1/pkg/unittest/lib/src/iterable...
> pkg/unittest/lib/src/iterable_matchers.dart:209: var e =
_expected.elementAt(i);
> any concern about the O(N^2) if this is a genuine iterable? I wonder if it's
> better to convert to List first.

Maybe I should just add a comment that users should be aware of this and can do
the conversion themselves; that avoids the cost of making a copy in other cases.

Or I could just wrap it if it is not a List already. What do you guys think?

[Siggi Cherem (dart-lang), 2013-05-08 00:31:32]

https://codereview.chromium.org/15017013/diff/1/pkg/unittest/lib/src/iterable...
File pkg/unittest/lib/src/iterable_matchers.dart (right):

https://codereview.chromium.org/15017013/diff/1/pkg/unittest/lib/src/iterable...
pkg/unittest/lib/src/iterable_matchers.dart:209: var e = _expected.elementAt(i);
On 2013/05/08 00:16:25, John Messerly wrote:
> any concern about the O(N^2) if this is a genuine iterable? I wonder if it's
> better to convert to List first.

you could use the iterable api and visit them concurrently?

var iterator = item.iterator;
var i = 0;
for (var e in _expected) {
  iterator.moveNext();
  if (!_comparator(e, iterator.current)) { ... 
  i++;

[gram, 2013-05-08 01:05:16]

PTAL

[Jennifer Messerly, 2013-05-08 01:07:15]

lgtm

[Siggi Cherem (dart-lang), 2013-05-08 01:36:49]

lgtm =)

[gram, 2013-05-08 18:22:48]

Committed patchset #2 manually as r22519 (presubmit successful).