Re: [RFC PATCH, WAS: "weird diff output?" 2/2] xdiff: implement empty line chunk heuristic

From: Junio C Hamano <gitster@pobox.com>
Date: Apr 15, 2016, 20:06 UTC
Message-ID: <xmqq8u0ebpru.fsf@gitster.mtv.corp.google.com>
In-Reply-To: <CAGZ79ka7h25=rHun_hPv1qjqeghXt1UwUU3Q6xT0aj4+OW87fg@mail.gmail.com>

Stefan Beller <sbeller@google.com> writes:

Show 15 quoted lines

>> +diff.emptyLineHeuristic::
>
> I was looking at the TODO here and thought about the name:
> It should not encode the `emptyLine` into the config option as
> it is only one of many heuristics.
>
> It should be something like `diff.heuristic=lastEmptyLine`
> The we could add firstEmptyLine, aggressiveUp, aggressiveDown,
> breakAtShortestLineLength or other styles as well later on.
>
> I do not quite understand the difference between diff.algorithm
> and the newly proposed heuristic as the heuristic is part of
> the algorithm? So I guess we'd need to have some documentation
> saying how these differ. (fundamental algorithm vs last minute
> style fixup?)

I actually do not think these knobs should exist when the code is mature enough to be shipped to the end users.

Use "diff.compactionHeuristics = <uint>" as an opaque set of bits to help the developers while they compare notes and reach consensus on a single tweak that they can agree on being good enough, and then remove that variable before the code hits 'next'.

Thanks.