Re: regexp matching in svn?

On Sat, Jan 28, 2012 at 9:54 AM, Daniel Shahaf <d.s_at_daniel.shahaf.name> wrote:
> On Fri, Jan 27, 2012, at 21:30, Johan Corveleyn wrote:
>> On Fri, Jan 27, 2012 at 4:44 PM, Bert Huijben <bert_at_qqmail.nl> wrote:
>> >> -----Original Message-----
>> >> From: Johan Corveleyn [mailto:jcorvel_at_gmail.com]
>> >> Sent: vrijdag 27 januari 2012 16:31
>> >> To: Subversion Development
>> >> Subject: regexp matching in svn?
>> >>
>> >> Hi,
>> >>
>> >> Is there any existing regexp matching functionality somewhere in de
>> >> svn codebase, in a way that is reusable for new functionality? If not,
>> >> does anyone know of a reusable third-party library that could be
>> >> easily intregrated (I know, it would be Yet Another Dependency, but
>> >> I'm just asking for options ...)?
>> >>
>> >> Use-case: I like the '-x-p' (show C-function) option for 'svn diff',
>> >> but this is limited to C-like syntax. GNU diff also has a '-F RE'
>> >> option, where RE is a regular expression that is used for matching the
>> >> "function-line". I know I could make use of this functionality by
>> >> invoking GNU diff as external diff command, but for several reasons it
>> >> would be interesting if svn could do this internally (for one thing:
>> >> GNU diff isn't always available / installed).
>> >>
>> >> And I'm sure there would be other useful things people could do with
>> >> regexp functionality ...
>> >
>> > Apr (or Apr-Util) has regex support, not sure which but we require both.
>>
>> Thanks, but I can't find it. I found apr_strmatch in apr-util, but
>> that doesn't do regex, it just matches a fixed string (which would
>> also be useful (it actually covers my concrete use-case), but it's not
>> -F). Maybe I'm overlooking something.
>>
>> If it's not in apr(-util) or some other dependency we already have,
>> how about PCRE (www.pcre.org) ?
>
> I must have missed the point where you explained why decreeing "GNU diff
> must be installed" company policy is not an option.

Yes, it's an option. But it's a hassle. I'm investigating other options.

Other than that, there is something about GNU diff's -F option that I
don't like: it doesn't trim leading whitespace from the matched
"function line", unlike the -p option.

If we implement this ourselves, we can decide to do this (depending on
community consensus of course). We don't have to do exactly the same
as GNU diff's -p / -F (just like we also show 50 characters of -p,
unlike GNU diff which shows 40 characters).

-- 
Johan