code review 5369090: spec: disallow general func, map comparisons

spec: disallow general func, map comparisons

[rsc, 2011-11-12 06:47:06]

Hello golang-dev@googlegroups.com,

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

[gri, 2011-11-12 06:52:34]

LGTM

I don't recall anymore why we decided to remove map comparison m1 == m2.

[r, 2011-11-12 16:07:45]

LGTM

http://codereview.appspot.com/5369090/diff/5001/doc/go_spec.html
File doc/go_spec.html (right):

http://codereview.appspot.com/5369090/diff/5001/doc/go_spec.html#newcode2969
doc/go_spec.html:2969: A slice, map, or function value may only be compared to
<code>nil</code>.
may be compared only to nil

put the "only" as near as possible to what it affects. "may only be compared"
reads like you can do only comparisons with a function, and then the "to nil"
requires you to rethink the parse.

[r2, 2011-11-12 16:09:39]

On Nov 11, 2011, at 10:52 PM, gri@golang.org wrote:

> LGTM
> 
> I don't recall anymore why we decided to remove map comparison m1 == m2.
> 
> http://codereview.appspot.com/5369090/

it's so you can't use them as keys in maps.

[rsc, 2011-11-12 16:33:18]

On Sat, Nov 12, 2011 at 01:52,  <gri@golang.org> wrote:
> I don't recall anymore why we decided to remove map comparison m1 == m2.

We removed m1 == m2 so that we have the option later
of defining map comparison as a deeper compare.

Russ

[r, 2011-11-12 16:56:37]

that too.

-rob

[rsc, 2011-11-14 03:57:45]

*** Submitted as http://code.google.com/p/go/source/detail?r=8ed90e9d30ab ***

spec: disallow general func, map comparisons

R=golang-dev, gri, r, r
CC=golang-dev
http://codereview.appspot.com/5369090