Re: [RFC/PATCH] add diff-pairs tool

From: Jeff King <peff@peff.net>
Date: Dec 1, 2016, 21:30 UTC
Message-ID: <20161201213019.qfkqd324ommikym2@sigill.intra.peff.net>
In-Reply-To: <xmqq7f7j8iz6.fsf@gitster.mtv.corp.google.com>

On Thu, Dec 01, 2016 at 12:58:21PM -0800, Junio C Hamano wrote:

Show 21 quoted lines

> Jeff King <peff@peff.net> writes:
> 
> > On Thu, Dec 01, 2016 at 12:52:05PM -0800, Junio C Hamano wrote:
> >
> >> Jeff King <peff@peff.net> writes:
> >> 
> >> > This takes the output of `diff-tree -z --raw` and feeds it
> >> > back to the later stages of the diff machinery to produce
> >> > diffs in other formats.
> >> 
> >> A full circle.  This reminds me of the experiment done more than 10
> >> years ago at the beginning of the "diffcore transformations" design.
> >
> > Heh, I didn't even think to dig for prior art on the list.
> 
> It took me a while to dig it up because the topic is so old, but
> 
> https://public-inbox.org/git/Pine.LNX.4.58.0504251832480.18901@ppc970.osdl.org/
> 
> is the thread I had in mind.  The idea of rename detection followed
> soon afterwards.

Thanks for an interesting read. Your diff-tree-helper patch is very similar to what I wrote.

I do think the right decision was made back then. The single-process model is much more efficient, and it was over 10 years until somebody actually wanted to expose the functionality to a script (and even now, I'm not convinced enough people want it to even merit inclusion).

-Peff