code review 1825043: Go specification: Lock down some details about channels...

Go specification: Lock down some details about channels and select:
- nil channel in regular send or receive panics
- empty select blocks forever

[r, 2010-07-13 22:30:25]

Hello rsc, gri, iant, ken2 (cc: golang-dev@googlegroups.com),

I'd like you to review this change.

[gri, 2010-07-13 22:58:17]

http://codereview.appspot.com/1825043/diff/1/2
File doc/go_spec.html (right):

http://codereview.appspot.com/1825043/diff/1/2#newcode3068
doc/go_spec.html:3068: in a communications clause of a <a
href="#Select_statements">select statement</a>.
Maybe shorter: (?)

Except in a communications clause of a select statement, sending or receiving
from a nil channel causes a run-time panic.

http://codereview.appspot.com/1825043/diff/1/2#newcode4068
doc/go_spec.html:4068: the statement will block forever.
s/will block/blocks/

Maybe worthwhile to emphasize the empty select case:

If there are no cases with non-nil channels (including select statements without
any cases), ....

Alternatively, perhaps add this case as an example.

http://codereview.appspot.com/1825043/diff/1/2#newcode4069
doc/go_spec.html:4069: Even if the statement blocks,
Perhaps:

In any case, the channel and send expressions are evaluated only once, upon
entering the select statement.

[r, 2010-07-13 23:03:40]

Hello rsc, gri, iant, ken2 (cc: golang-dev@googlegroups.com),

Please take another look.

[gri, 2010-07-13 23:07:23]

LGTM

On Tue, Jul 13, 2010 at 4:03 PM, <r@golang.org> wrote:

> Hello rsc, gri, iant, ken2 (cc: golang-dev@googlegroups.com),
>
> Please take another look.
>
>
> http://codereview.appspot.com/1825043/show
>

[rsc1, 2010-07-13 23:22:25]

LGTM

[r, 2010-07-13 23:24:09]

*** Submitted as http://code.google.com/p/go/source/detail?r=4a65a2f4024f ***

Go specification: Lock down some details about channels and select:
- nil channel in regular send or receive panics
- empty select blocks forever

R=rsc, gri, iant, ken2
CC=golang-dev
http://codereview.appspot.com/1825043