code review 5619052: std: add struct field tags to untagged literals.

std: add struct field tags to untagged literals.

[nigeltao, 2012-02-02 06:50:59]

Hello rsc@golang.org (cc: golang-dev@googlegroups.com),

I'd like you to review this change to
https://go.googlecode.com/hg/

[dsymonds, 2012-02-02 07:00:33]

LGTM

http://codereview.appspot.com/5619052/diff/3023/src/pkg/image/draw/draw_test.go
File src/pkg/image/draw/draw_test.go (right):

http://codereview.appspot.com/5619052/diff/3023/src/pkg/image/draw/draw_test....
src/pkg/image/draw/draw_test.go:315: c := color.RGBA{R: 11, G: 0, B: 0, A: 255}
color.RGBA is frozen; you don't need to change this.

http://codereview.appspot.com/5619052/diff/3023/src/pkg/image/draw/draw_test....
src/pkg/image/draw/draw_test.go:335: c = color.RGBA{R: 0, G: 22, B: 0, A: 255}
ditto

http://codereview.appspot.com/5619052/diff/3023/src/pkg/image/draw/draw_test....
src/pkg/image/draw/draw_test.go:342: c = color.RGBA{R: 0, G: 0, B: 33, A: 255}
ditto

http://codereview.appspot.com/5619052/diff/3023/src/pkg/image/draw/draw_test....
src/pkg/image/draw/draw_test.go:349: c = color.RGBA{R: 44, G: 55, B: 66, A: 77}
ditto

[nigeltao, 2012-02-02 07:05:49]

http://codereview.appspot.com/5619052/diff/3023/src/pkg/image/draw/draw_test.go
File src/pkg/image/draw/draw_test.go (right):

http://codereview.appspot.com/5619052/diff/3023/src/pkg/image/draw/draw_test....
src/pkg/image/draw/draw_test.go:315: c := color.RGBA{R: 11, G: 0, B: 0, A: 255}
On 2012/02/02 07:00:33, dsymonds wrote:
> color.RGBA is frozen; you don't need to change this.

True, but it looked weird to use an untagged struct literal on one line and a
tagged one on the next.

[bsiegert, 2012-02-02 10:24:36]

On Thu, Feb 2, 2012 at 07:50,  <nigeltao@golang.org> wrote:
> std: add struct field tags to untagged literals.

Why?

--Benny.

[rog, 2012-02-02 14:44:56]

so that fields can be added to types in the standard library in a backwardly
compatible way.

On 2 February 2012 10:24, Benny Siegert <bsiegert@gmail.com> wrote:
> On Thu, Feb 2, 2012 at 07:50,  <nigeltao@golang.org> wrote:
>> std: add struct field tags to untagged literals.
>
> Why?
>
> --Benny.

[rsc, 2012-02-02 17:34:32]

I thought we agreed to have an exception table
that would cover image.Point and color.RGBAxx?

Russ

[rsc, 2012-02-02 17:35:52]

Sorry, missed Nigel's earlier reply in the thread.
Please drop the tags from RGBA.  If nothing else
it is a good test case for the govet module.

Russ

[nigeltao, 2012-02-02 22:57:48]

http://codereview.appspot.com/5619052/diff/3023/src/pkg/image/draw/draw_test.go
File src/pkg/image/draw/draw_test.go (right):

http://codereview.appspot.com/5619052/diff/3023/src/pkg/image/draw/draw_test....
src/pkg/image/draw/draw_test.go:315: c := color.RGBA{R: 11, G: 0, B: 0, A: 255}
On 2012/02/02 07:05:49, nigeltao wrote:
> On 2012/02/02 07:00:33, dsymonds wrote:
> > color.RGBA is frozen; you don't need to change this.
> 
> True, but it looked weird to use an untagged struct literal on one line and a
> tagged one on the next.

The color.RGBA changes have been reverted.

[rsc, 2012-02-02 23:06:09]

LGTM but revert html/template/clone.go

http://codereview.appspot.com/5619052/diff/5003/src/pkg/html/template/clone.go
File src/pkg/html/template/clone.go (left):

http://codereview.appspot.com/5619052/diff/5003/src/pkg/html/template/clone.g...
src/pkg/html/template/clone.go:40: // We use keyless fields because they won't
compile if a field is added.
It's hard to argue with this logic.
The tree doesn't have to be perfectly free of these
and if the goal is non-compilation, then fine.
This is in the standard library after all.

Please revert this file.

[nigeltao, 2012-02-02 23:12:31]

*** Submitted as http://code.google.com/p/go/source/detail?r=756477d03441 ***

std: add struct field tags to untagged literals.

R=rsc, dsymonds, bsiegert, rogpeppe
CC=golang-dev
http://codereview.appspot.com/5619052