Re: Default setting for sh-maybe-here-document-mode

[Philipp Stephani <p.stephani2@gmail.com>]

[-- Attachment #1: Type: text/plain, Size: 4392 bytes --]

Thibaut Verron <thibaut.verron@gmail.com> schrieb am Fri Feb 20 2015 at
16:50:02:

> 2015-02-20 14:58 GMT+01:00 Stefan Monnier <monnier@iro.umontreal.ca>:
>
>> > I was wondering why is `sh-electric-here-document-mode` activated by
>> > default for new documents in `sh-mode`?
>>
>> IIRC I turned it into a minor mode and made it "enabled by default"
>> because the corresponding functionality was active by default before
>> (i.e. I just tried to preserve the previous behavior).
>>
>> > I was under the impression that in most cases, this kind of commands,
>> > inserting text beyond what the user types, without requiring anything
>> > besides text input, are disabled by default.
>>
>> We don't really have a clear policy on this.  I generally tend to prefer
>> keeping those things disabled, indeed, but OTOH electric-indent-mode is
>> now enabled by default (which is a pretty major counter example).
>>
>
> Imo electric-indent-mode is way less intrusive than the electric here
> document, but maybe that's only because I'm used to it. At least, a lot of
> other editors implement a similar feature, so emacs won't stand out as an
> annoyance for auto-indenting.
>
>
>>
>> > And why is it so hard to disable it once you find out where the annoying
>> > behavior comes from?
>>
>> Hmm... indeed, maybe it should be a global minor mode?
>>
>
> And auto-loaded? This could work. Another option would be to reenable the
> binding on '<' (see just below), and let users who do not want the behavior
> use self-insert-command.
>
>
>>
>> > (Just see how many articles deal with this specific
>> > issue; and having changed the name of the mode in 24.3 doesn't help)
>>
>> I haven't noticed this, no.  Neither on gnu.emacs.help nor on
>> stackoverflow.
>>
>
> See for example http://unix.stackexchange.com/q/20121/47331
>
> Notice the number of different answers/workarounds! And the accepted
> answer (probably the most natural) does not even work anymore: on 24.3, <
> is bound to self-insert-command by default, yet it does trigger the
> behavior. Side note: this is the only case I can think of where
> self-insert-command does something else than inserting the character. It is
> probably a bug by itself.
>
> As another metric, you can google "sh-electric-here-document-mode" : I
> don't see a single link which is not either completely unrelated or asking
> how to disable it. (Sorry for biasing the measure with the present thread)
>
>
>
>> > I understand that changing defaults is sensible, but in this case,
>> wouldn't
>> > it be worth it? In my opinion, the only people who may appreciate this
>> > setting are people who know how to use C-q to work around it, and these
>> > people will know how to reactivate it.
>>
>> It should (supposedly) be very rare that it triggers by accident.
>>
>> If you have some sample scenarios where it triggers when it's undesired,
>> maybe we can fine-tune it to avoid those,
>>
>
> It is very easy: try to feed a single line to a command, using a
> here-string. In other words, try to enter
>
>     command <<< "line of text"
>
> As an anecdote, I am TA in a course where students learn about emacs and
> shell scripting, and I have seen mainly two reactions to this feature:
> "I got back to gedit because it didn't have the issue"
> "I use 'echo ... | ... ' instead of here-line because it is easier to type
> on emacs" (And this work-around will lead to different problems, for
> example if command is supposed to change the environment)
>
> This use-case can be accommodated with this piece of code:
> http://emacs.stackexchange.com/a/5338/184
> It still fails in case the here-document is supposed to start with a <,
> which is reasonable, but would probably be even more confusing as a default.
>
> Another use-case, even if you never use here-strings, is that you want to
> enter a single <, but enter << instead. You would expect this mistake to be
> corrected with a single backspace, but it's not.
>
> By the way, we could design it so that the feature is still accessible,
> but through more conventional entry points, for example by pressing TAB
> with point after << .
>
> Thibaut Verron
>

+1 to disabling this feature by default. It's easily the most annoying
part of shell scripting in Emacs for me (I use herestrings at least as
often as heredocs). I agree that this is way more intrusive and confusing
than electric indentation.

[-- Attachment #2: Type: text/html, Size: 6933 bytes --]