bug#21921: New function comment-line also comments first line after region

bug#21921: New function comment-line also comments first line after region

[Clément Pit--Claudel]

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Hi all,

The new comment-line feature is very convenient, but I find its operation slightly confusing wrt the "comment out region" feature.

Its documentation says:

  If region is active, comment lines in active region instead.

However, it seems that it also comments out the line just after the end
of the region.

For example, given the following text

abc
def
ghi

Placing the cursor before `a', then pressing C-SPC C-n C-n, causes two
lines to be marked: (> is highlighting, | is point)

>abc
>def
|ghi

Yet pressing C-x C-; (comment-region) comments out all three lines.

Similarly, again starting from 

abc
def
ghi

placing the point before `g' and pressing C-SPC C-p C-p causes two lines
to be marked:

>|abc
>def
ghi

Yet pressing C-x C-; comments out all three lines. I find this second example especially confusing.

Is this behaviour only surprising to me?

Cheers,
Clément.

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bug#21921: New function comment-line also comments first line after region

[Rasmus]

Hi Clément,

Thanks for details report.

Clément Pit--Claudel <clement.pitclaudel@live.com> writes:

> Its documentation says:
>
>   If region is active, comment lines in active region instead.
>
> However, it seems that it also comments out the line just after the end
> of the region.
>
> For example, given the following text
>
> abc
> def
> ghi
>
> Placing the cursor before `a', then pressing C-SPC C-n C-n, causes two
> lines to be marked: (> is highlighting, | is point)
>
>>abc
>>def
> |ghi
>
> Yet pressing C-x C-; (comment-region) comments out all three lines.

Because the end of region is at point.  Try to run this:

        (list (point)  (region-beginning) (region-end))

Also, from the docstring,

      Unlike ‘comment-dwim’, this always comments whole lines.

You'd get what you'd expect if you run comment-dwim (M-;)

> Similarly, again starting from 
>
> abc
> def
> ghi
>
> placing the point before `g' and pressing C-SPC C-p C-p causes two lines
> to be marked:

Again, in fact the region start at 'g'.  Check e.g. with C-x C-x.  But
it's not obvious from the face.

>>|abc
>>def
> ghi
>
> Yet pressing C-x C-; comments out all three lines. I find this second example especially confusing.
>
> Is this behaviour only surprising to me?

Perhaps the confusion is caused by region not being displayed at column
zero.

The behavior is correct IMO.

For your particular examples, comment-dwim does what you want, it seems.

Hope it helps,
Rasmus

-- 
Spil noget med Slayer!

bug#21921: New function comment-line also comments first line after region

[Artur Malabarba]

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On 15 Nov 2015 11:45 am, "Rasmus" <rasmus@gmx.us> wrote:
> >
> > Yet pressing C-x C-; comments out all three lines. I find this second
example especially confusing.
> >
> > Is this behaviour only surprising to me?
>
> Perhaps the confusion is caused by region not being displayed at column
> zero.
>
> The behavior is correct IMO.
>
> For your particular examples, comment-dwim does what you want, it seems.
>
> Hope it helps,
> Rasmus

Indeed. When I was deciding how comment-line should work on a region, I
specifically chose to not make it identical to comment-dwim.

Maybe it should still treat the "region ends at a newline" case specially.
Some emacs commands do that already.
Not sure though, since that would be slightly redundant with comment-dwim.

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bug#21921: New function comment-line also comments first line after region

[Rasmus]

Artur Malabarba <bruce.connor.am@gmail.com> writes:

> Indeed. When I was deciding how comment-line should work on a region, I
> specifically chose to not make it identical to comment-dwim.
>
> Maybe it should still treat the "region ends at a newline" case specially.
> Some emacs commands do that already.
> Not sure though, since that would be slightly redundant with comment-dwim.

It's already in comment-dwim.  On my layout, comment-dwim is easier to
reach anyway.  I’m indifferent on the behavior of comment-line in this
edge case.  Both would make sense.

Rasmus

-- 
This is the kind of tedious nonsense up with which I will not put

bug#21921: New function comment-line also comments first line after region

[Andreas Röhler]

  On 16.11.2015 18:59, Rasmus wrote:
> Artur Malabarba<bruce.connor.am@gmail.com>  writes:
>
>> Indeed. When I was deciding how comment-line should work on a region, I
>> specifically chose to not make it identical to comment-dwim.
>>
>> Maybe it should still treat the "region ends at a newline" case specially.
>> Some emacs commands do that already.
>> Not sure though, since that would be slightly redundant with comment-dwim.
> It's already in comment-dwim.  On my layout, comment-dwim is easier to
> reach anyway.  I’m indifferent on the behavior of comment-line in this
> edge case.  Both would make sense.
>
> Rasmus
>

Being in favor to keep it as implemented. Congrats BTW. Use this feature 
for years personally, glad to see it built-in now.
IMO it's most useful as line-oriented command. Moving one line down, 
being ready for repeat.

Cheers,

Andreas

bug#21921: New function comment-line also comments first line after region

[npostavs]

tags 21921 notabug wontfix
close 21921
quit

Rasmus <rasmus@gmx.us> writes:

> Perhaps the confusion is caused by region not being displayed at column
> zero.
>
> The behavior is correct IMO.
>

Artur Malabarba <bruce.connor.am@gmail.com> writes:

> Indeed. When I was deciding how comment-line should work on a region, I specifically chose to not make it identical to comment-dwim. 
>
> Maybe it should still treat the "region ends at a newline" case specially. Some emacs commands do that already.
> Not sure though, since that would be slightly redundant with comment-dwim. 

Andreas Röhler <andreas.roehler@easy-emacs.de> writes:

> Being in favor to keep it as implemented. Congrats BTW. Use this
> feature for years personally, glad to see it built-in now.
> IMO it's most useful as line-oriented command. Moving one line down,
> being ready for repeat.


I think we've decided it's okay as is, closing.