code review 10743046: cmd/gc: support x[i:j:k]

cmd/gc: support x[i:j:k]

Design doc at golang.org/s/go12slice.
This is an experimental feature and may not be included in the release.

[rsc, 2013-06-28 22:05:08]

Hello golang-dev@googlegroups.com,

I'd like you to review this change to
https://code.google.com/p/go/

[r, 2013-07-01 17:02:39]

https://codereview.appspot.com/10743046/diff/6001/src/cmd/gc/typecheck.c
File src/cmd/gc/typecheck.c (right):

https://codereview.appspot.com/10743046/diff/6001/src/cmd/gc/typecheck.c#newc...
src/cmd/gc/typecheck.c:1802: yyerror("inverted slice index %N > %N", lo, hi);
not the best message; not even clear how to parse it. (is it the slice or the
index that's inverted, and what does 'inverted' mean?)

suggestion: "invalid slice indexes: %N > %N"

[rsc, 2013-07-01 21:26:57]

PTAL

https://codereview.appspot.com/10743046/diff/6001/src/cmd/gc/typecheck.c
File src/cmd/gc/typecheck.c (right):

https://codereview.appspot.com/10743046/diff/6001/src/cmd/gc/typecheck.c#newc...
src/cmd/gc/typecheck.c:1802: yyerror("inverted slice index %N > %N", lo, hi);
On 2013/07/01 17:02:39, r wrote:
> not the best message; not even clear how to parse it. (is it the slice or the
> index that's inverted, and what does 'inverted' mean?)
> 
> suggestion: "invalid slice indexes: %N > %N"

Changed to "invalid slice index: %N > %N".

[r, 2013-07-01 23:52:28]

LGTM as an experiment.
y.tab.c won't load in codereview

[rsc, 2013-07-02 00:32:41]

*** Submitted as https://code.google.com/p/go/source/detail?r=ed9fb0ef363c ***

cmd/gc: support x[i:j:k]

Design doc at golang.org/s/go12slice.
This is an experimental feature and may not be included in the release.

R=golang-dev, r
CC=golang-dev
https://codereview.appspot.com/10743046

[bradfitz, 2013-07-02 00:44:07]

Open season?

What are the rules?  Specifically: are performance-related CLs acceptable?


On Mon, Jul 1, 2013 at 5:32 PM, <rsc@golang.org> wrote:

> *** Submitted as
>
https://code.google.com/p/go/**source/detail?r=ed9fb0ef363c<https://code.goog...
>
>
> cmd/gc: support x[i:j:k]
>
> Design doc at golang.org/s/go12slice.
> This is an experimental feature and may not be included in the release.
>
> R=golang-dev, r
> CC=golang-dev
>
https://codereview.appspot.**com/10743046<https://codereview.appspot.com/1074...
>
>
>
>
https://codereview.appspot.**com/10743046/<https://codereview.appspot.com/107...
>
> --
>
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[rsc, 2013-07-02 01:21:58]

Wait for Rob, but I believe it is okay to use in the tree in any way. The
goal is to understand how it will be used. Keep in mind that we may need to
back out all the uses if we decide not to go forward with it, although I
think that it's more likely we'll keep it in some form.

Russ

[btracey, 2013-07-02 13:31:58]

Just curious, what has changed since

https://code.google.com/p/go/issues/detail?id=4371&can=1&q=brendan&colspec=ID...


On Monday, July 1, 2013 9:21:57 PM UTC-4, rsc wrote:
>
> Wait for Rob, but I believe it is okay to use in the tree in any way. The 
> goal is to understand how it will be used. Keep in mind that we may need to 
> back out all the uses if we decide not to go forward with it, although I 
> think that it's more likely we'll keep it in some form.
>
> Russ
>
>

[DMorsing, 2013-07-02 13:41:37]

On 2013/07/02 13:31:58, tracey.brendan_gmail.com wrote:
> Just curious, what has changed since
> 
>
https://code.google.com/p/go/issues/detail?id=4371&can=1&q=brendan&colspec=ID...
> 
> 

This is unrelated to slice striding. Read golang.org/s/go12slice for more info.

[btracey, 2013-07-02 14:01:33]

I hadn't seen that, thank you

[r, 2013-07-03 01:45:14]

Brad: Enjoy.