code review 5528077: go/scanner: remove (exported) InsertSemis mode

go/scanner: remove (exported) InsertSemis mode

This is a relic from the times when we switched
to automatic semicolon insertion. It's still use-
ful to have a non-exported switch for testing.

[gri, 2012-01-11 17:28:10]

Hello golang-dev@googlegroups.com,

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

[r, 2012-01-11 17:30:48]

LGTM
s/relict/relic/ in the CL description

i always push back against negative flags, in this case "dontInsertSemis". they
make the logic tricky.

if x & dontInsertSemis == 0 { .. }

is a double negative. i think.

[gri, 2012-01-11 17:43:09]

On Wed, Jan 11, 2012 at 9:30 AM,  <r@golang.org> wrote:
> LGTM
> s/relict/relic/ in the CL description
Done
>
> i always push back against negative flags, in this case
> "dontInsertSemis". they make the logic tricky.
>
> if x & dontInsertSemis == 0 { .. }
>
> is a double negative. i think.
One could call it IgnoreImplicitSemis or something like that. But the
flag needs to have the opposite sense from what it had before.
- gri


>
> http://codereview.appspot.com/5528077/

[rsc, 2012-01-11 17:58:22]

LGTM

[r2, 2012-01-11 18:06:40]

On Jan 11, 2012, at 9:43 AM, Robert Griesemer wrote:

> One could call it IgnoreImplicitSemis or something like that. But the
> flag needs to have the opposite sense from what it had before.

you can leave it if you prefer, but i don't understand this comment. you can
invert the meaning of the flag by inverting its tests.

-rob

[gri, 2012-01-11 18:06:47]

*** Submitted as http://code.google.com/p/go/source/detail?r=4c300745d3c3 ***

go/scanner: remove (exported) InsertSemis mode

This is a relic from the times when we switched
to automatic semicolon insertion. It's still use-
ful to have a non-exported switch for testing.

R=golang-dev, r, rsc
CC=golang-dev
http://codereview.appspot.com/5528077

[gri, 2012-01-11 18:14:50]

On Wed, Jan 11, 2012 at 10:06 AM, Rob 'Commander' Pike <r@google.com> wrote:
>
> On Jan 11, 2012, at 9:43 AM, Robert Griesemer wrote:
>
>> One could call it IgnoreImplicitSemis or something like that. But the
>> flag needs to have the opposite sense from what it had before.
>
> you can leave it if you prefer, but i don't understand this comment. you can
invert the meaning of the flag by inverting its tests.

Before, all clients that wanted default Go scanner behavior needed to
explicitly set the flag "InsertSemis". Now that it is gone, i.e.,
"InsertSemis" is on by default, I need a flag (for testing) to turn
"InsertSemis" off. Which is why the new flag needs to have the
inverted meaning of the old one.

I am hoping to eliminate the flag altogether, but I didn't want to
fiddle with the somewhat delicate tests (because of position
information etc.) for now.

- gri