code review 4439087: go/printer: make tests follow syntactic restrictions

go/printer: make tests follow syntactic restrictions

[gri, 2011-05-02 16:37:16]

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

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

[rsc, 2011-05-02 16:42:19]

I'm confused.  I thought the parser would continue to
accept expression statements so that a higher-level
layer could reject them along with calls like len(x).
So I thought this wouldn't need to change.

[gri, 2011-05-02 16:48:19]

It doesn't need to change. But there's nothing wrong with changing it.
What is the problem with it?
- Robert

On Mon, May 2, 2011 at 9:42 AM, Russ Cox <rsc@golang.org> wrote:
> I'm confused.  I thought the parser would continue to
> accept expression statements so that a higher-level
> layer could reject them along with calls like len(x).
> So I thought this wouldn't need to change.
>

[rsc, 2011-05-02 16:51:23]

On Mon, May 2, 2011 at 12:48, Robert Griesemer <gri@golang.org> wrote:
> It doesn't need to change. But there's nothing wrong with changing it.
> What is the problem with it?

There's no problem except that it makes it look like
statement-level expressions are rejected by the parser,
and it's important that they not be rejected (for the
reasons we identified last week, including using the
statement parser during an interpreter input loop).

Can we leave a few?

[gri, 2011-05-02 17:00:29]

PTAL.

- gri

On Mon, May 2, 2011 at 9:51 AM, Russ Cox <rsc@golang.org> wrote:
> On Mon, May 2, 2011 at 12:48, Robert Griesemer <gri@golang.org> wrote:
>> It doesn't need to change. But there's nothing wrong with changing it.
>> What is the problem with it?
>
> There's no problem except that it makes it look like
> statement-level expressions are rejected by the parser,
> and it's important that they not be rejected (for the
> reasons we identified last week, including using the
> statement parser during an interpreter input loop).
>
> Can we leave a few?
>

[rsc, 2011-05-02 17:03:18]

LGTM

[gri, 2011-05-02 17:05:45]

*** Submitted as http://code.google.com/p/go/source/detail?r=039cd4ad46ee ***

go/printer: make tests follow syntactic restrictions

R=rsc
CC=golang-dev
http://codereview.appspot.com/4439087