Re: Meld roadmap proposals

[Kai <kai willadsen gmail com>]

On 9 July 2010 17:33, Piotr Piastucki <leech miranda gmail com> wrote:
> Hi,
>
>> Often times the diff engine fragments the differences in my
>> text so badly that meld becomes useless.  Common segments of
>> text split the diff in very odd and non-helpful ways.  I
>> recognize algorithmic marking of file differences is a very
>> complex effort, probably beyond the scope of the meld project.
>>
>
> I am interested if other diff algorithms can yield better results.
> There are at least 2 alternatives: Myers' diff and patience diff. However,
> the later does not seem to be suitable for assembly language files as it
> relies on line uniqueness.
> Would it be possible to provide some examples of files you need to compare?
> If not, then a slightly modified meld code that uses Myers' diff is
> available here: http://piastucki.bdl.pl/meld/meld_myers.tar.gz. Feel free to
> give it a try.

I've recently been looking at a couple of bugs that highlight the
weaknesses of the built-in Python difflib. Going by the open bugs
filed against it, it looks like the difflib module is in
low-maintenance mode at this point, leaving us to fix these problems
ourselves.

Ages ago when you first submitted the Myers diff implementation, you
said that it was slower than the difflib implementation; do you have
any idea how much slower? I'd be interested in finding out whether
switching to Myers wholesale would be a reasonable thing to do.

Also, there is an implementation of Myers diff in Review Board (in
reviewboard/diffviewer/myersdiff.py). It may be worthwhile looking at
that code (and other related bits) to see whether there is anything we
can share/appropriate for use in Meld.

cheers,
Kai