Add StreamChannelTransformer.

Add StreamChannelTransformer.

This makes StreamChannel.transform() take a StreamChannelTransformer
rather than a codec. This is better, since a codec is explicitly
intended to convert chunked data, while transformers are more general.

R=rnystrom@google.com

Committed: https://github.com/dart-lang/stream_channel/commit/8e628719a7ed4d7974c9a746d9de9da8f292f640

[nweiz, 2016-01-27 01:28:56]

nweiz@google.com changed reviewers:
+ rnystrom@google.com

[nweiz, 2016-01-27 01:28:56]

After talking to Lasse and Florian about a potential Codec, they convinced me
that it should be a transformer instead. So this adds a type of transformer for
it to be.

[Bob Nystrom, 2016-01-27 19:30:41]

lgtm

https://codereview.chromium.org/1632903004/diff/1/lib/src/isolate_channel.dart
File lib/src/isolate_channel.dart (right):

https://codereview.chromium.org/1632903004/diff/1/lib/src/isolate_channel.dar...
lib/src/isolate_channel.dart:131: if (_isDone) return new Future.value();
I wonder if it would be cleaner to make the function async? Then you could await
the completer's future below too.

https://codereview.chromium.org/1632903004/diff/1/lib/src/stream_channel_tran...
File lib/src/stream_channel_transformer.dart (right):

https://codereview.chromium.org/1632903004/diff/1/lib/src/stream_channel_tran...
lib/src/stream_channel_transformer.dart:19: /// Transformers must be able to
have `bind` called used multiple times.
Remove "used".

[nweiz, 2016-01-27 23:23:25]

Code review changes

[nweiz, 2016-01-27 23:23:49]

https://codereview.chromium.org/1632903004/diff/1/lib/src/isolate_channel.dart
File lib/src/isolate_channel.dart (right):

https://codereview.chromium.org/1632903004/diff/1/lib/src/isolate_channel.dar...
lib/src/isolate_channel.dart:131: if (_isDone) return new Future.value();
On 2016/01/27 19:30:40, Bob Nystrom wrote:
> I wonder if it would be cleaner to make the function async? Then you could
await
> the completer's future below too.

It seems weird to have the errors thrown asynchronously when the rest of the
methods throw them synchronously.

https://codereview.chromium.org/1632903004/diff/1/lib/src/stream_channel_tran...
File lib/src/stream_channel_transformer.dart (right):

https://codereview.chromium.org/1632903004/diff/1/lib/src/stream_channel_tran...
lib/src/stream_channel_transformer.dart:19: /// Transformers must be able to
have `bind` called used multiple times.
On 2016/01/27 19:30:41, Bob Nystrom wrote:
> Remove "used".

Done.

[nweiz, 2016-01-27 23:24:50]

Description was changed from

==========
Add StreamChannelTransformer.

This makes StreamChannel.transform() take a StreamChannelTransformer
rather than a codec. This is better, since a codec is explicitly
intended to convert chunked data, while transformers are more general.
==========

to

==========
Add StreamChannelTransformer.

This makes StreamChannel.transform() take a StreamChannelTransformer
rather than a codec. This is better, since a codec is explicitly
intended to convert chunked data, while transformers are more general.

R=rnystrom@google.com

Committed:
https://github.com/dart-lang/stream_channel/commit/8e628719a7ed4d7974c9a746d9...
==========

[nweiz, 2016-01-27 23:24:51]

Committed patchset #2 (id:20001) manually as
8e628719a7ed4d7974c9a746d9de9da8f292f640 (presubmit successful).