[Geany] UNindent close of statement

[Jiří Techet]

On Fri, Aug 6, 2010 at 10:42, Lex Trotman <elextr at gmail.com> wrote:
> On 6 August 2010 17:46, John Yeung <gallium.arsenide at gmail.com> wrote:
>> On Thu, Aug 5, 2010 at 6:54 PM, Jiří Techet <techet at gmail.com> wrote:
>>> By coincidence, I have been playing with TextMate under MacOS and it
>>> has an extremely elegant system of indent detection, see:
>>>
>>> http://manual.macromates.com/en/appendix#indentation_rules
>>
>> It does seem elegant.  I actually have wondered why there aren't more
>> editors that do this, and I had always thought maybe it was just not
>> as fast to use regexes.  But I could be wrong, and even if regexes are
>> indeed slower, they might certainly be Fast Enough (tm) on today's
>> computers.
>
> Glib regex uses PCRE which seems to have reasonable performance (From
> Boost Regex performance comparisons with other regex engines) where
> times are sub .001 sec for files about the length of Geany source
> files.  I'd say that was Fast Enough (C).

That sounds really good. Of course the exact numbers depend on for how
long the regex is a candidate to match a line - the results will be
better if it fails on the first character in every line than on the
last character. But since we will be matching against a single line,
this should be a non-issue.

>
>>
>>> Some observations from playing with TextMate:
>>> 1. increaseNextLinePattern is not normally used, see
>>>
>>> http://ticket.macromates.com/show?ticket_id=425D3D1C
>>>
>>> so we could drop it.
>>
>> I disagree.  The bracketless if-statement (or other single-line
>> "blocks") is extremely common, and SciTE has relatively ugly code just
>> to handle that case.
>>
>>> 2. decreaseIndentPattern appears to be matched against the current
>>> line after every single keypress (e.g. once you type ':' in "elsif:"
>>> in python, the line containing it unindents). Apparently regex
>>> matching is fast enough to do this. The other patterns are matched
>>> only when enter is pressed.
>>
>> Well, Python uses elif, not elsif.  But aside from that, Python is a
>> very special case.  It would be more natural for Python to not have
>> any automatic decreases, since your elif might apply to not the latest
>> if but rather a previous one (more than one level deep).  In Python,
>> it really makes sense for the programmer to explicitly decide the
>> amount of de-indentation,
>
> I agree with that, Geany does my Python fine because it doesn't get in
> the way, but some may like additional "help".  So long as I can turn
> it off per language too.
>
> and Python programmers are used to making
>> this decision for every single block.  It would be very weird to have
>> elif be an oddball that doesn't fall in line with everything else in
>> the language.
>>
>> For the record, Python should be a very easy language to get right
>> with the autoindentation, and it is kind of surprising how many
>> editors still manage to mess it up.  If I recall correctly, last time
>> I used Geany (several versions ago), it handled Python quite well
>> (either perfectly, or only quite unlikely situations could mess it
>> up).
>>
>>> I wonder how much illegal/unethical it is to copy
>>> configuration options from a commercial editor...
>>
>> In my opinion, it is not unethical at all.  I would not want to be a
>> part of copying or stealing someone else's not-open-source source
>> code, but I have no problem with the idea of reimplementing a
>> published spec.  I don't know if the law agrees with me.
>
> Too complicated since it is likely that it depends on which country
> you are in as to legality.  But I would observe that there is likely
> to be only one optimal regex for each language for each setting so
> even from first principles you will likely get the same answer ;-)

Well, after some more exploration this looks quite good. The bundles
SVN for TextMate is here:

http://svn.textmate.org/trunk/

and the license says this:

http://svn.textmate.org/trunk/LICENSE

Under tags you can find settings for all the files:

http://svn.textmate.org/tags/release_1.1b5/

including indentation settings. So I think we could use it, at least
as a base for further customization if we are not satisfied with the
settings.

Cheers,

Jiri

>
> Cheers
> Lex
>
>>
>> John
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