code review 2103046: bufio: add UnreadRune.

bufio: add UnreadRune.

[r, 2010-09-10 01:37:57]

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

I'd like you to review this change.

[rsc1, 2010-09-12 03:46:38]

LGTM

http://codereview.appspot.com/2103046/diff/3001/src/pkg/bufio/bufio.go
File src/pkg/bufio/bufio.go (right):

http://codereview.appspot.com/2103046/diff/3001/src/pkg/bufio/bufio.go#newcod...
src/pkg/bufio/bufio.go:223: // UnreadRune unreads the last rune.  If the most
recent successful read
s/successful //

[r, 2010-09-12 03:59:33]

I arranged that a read at eof does not undo the state, hence the
adjective. lose it anyway?

On Sunday, September 12, 2010,  <rsc@google.com> wrote:
> LGTM
>
>
>
> http://codereview.appspot.com/2103046/diff/3001/src/pkg/bufio/bufio.go
> File src/pkg/bufio/bufio.go (right):
>
>
http://codereview.appspot.com/2103046/diff/3001/src/pkg/bufio/bufio.go#newcod...
> src/pkg/bufio/bufio.go:223: // UnreadRune unreads the last rune.  If the
> most recent successful read
> s/successful //
>
> http://codereview.appspot.com/2103046/
>

[rsc, 2010-09-12 04:08:51]

On Sat, Sep 11, 2010 at 23:59, Rob 'Commander' Pike <r@golang.org> wrote:
> I arranged that a read at eof does not undo the state, hence the
> adjective. lose it anyway?

Yes.  A normal Read might discard a full buffer in preparation
to get more data, resetting b.r and b.w, only to have the read fail.
That was an unsuccessful read operation but UnreadRune is
no longer possible.

Russ

[r, 2010-09-12 07:40:31]

*** Submitted as http://code.google.com/p/go/source/detail?r=866735192f2d ***

bufio: add UnreadRune.

R=rsc
CC=golang-dev
http://codereview.appspot.com/2103046

Committer: Rob Pike <r@golang.org>