The diff-so-fancy project is also written in perl, and most
of its users pipe diffs through both diff-highlight and
diff-so-fancy. It would be nice if this could be done in a
single script. So let's pull most of diff-highlight's code
into its own module which can be used by diff-so-fancy.
In addition, we'll abstract a few basic items like reading
from stdio so that a script using the module can do more
processing before or after diff-highlight handles the lines.
See the README update for more details.
One small downside is that the diff-highlight script must
now be built using the Makefile. There are ways around this,
but it quickly gets into perl arcana. Let's go with the
simple solution. As a bonus, our Makefile now respects the
PERL_PATH variable if it is set.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Until now, the highlighting colors were hard-coded in the
script (as "reverse" and "noreverse"), and you had to edit
the script to change them. This patch teaches diff-highlight
to read from color.diff-highlight.* to set them.
In addition, it expands the possiblities considerably by
adding two features:
1. Old/new lines can be colored independently (so you can
use a color scheme that complements existing line
coloring).
2. Normal, unhighlighted parts of the lines can be colored,
too. Technically this can be done by separately
configuring color.diff.old/new and matching it to your
diff-highlight colors. But you may want a different
look for your highlighted diffs versus your regular
diffs.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The diff-highlight script works on heuristics, so it can be
wrong. Let's document some of the wrong-ness in case
somebody feels like working on it.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Currently we only bother highlighting single-line hunks. The
rationale was that the purpose of highlighting is to point
out small changes between two similar lines that are
otherwise hard to see. However, that meant we missed similar
cases where two lines were changed together, like:
-foo(buf);
-bar(buf);
+foo(obj->buf);
+bar(obj->buf);
Each of those changes is simple, and would benefit from
highlighting (the "obj->" parts in this case).
This patch considers whole hunks at a time. For now, we
consider only the case where the hunk has the same number of
removed and added lines, and assume that the lines from each
segment correspond one-to-one. While this is just a
heuristic, in practice it seems to generate sensible
results (especially because we now omit highlighting on
completely-changed lines, so when our heuristic is wrong, we
tend to avoid highlighting at all).
Based on an original idea and implementation by Michał
Kiedrowicz.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This is a simple and stupid script for highlighting
differing parts of lines in a unified diff. See the README
for a discussion of the limitations.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
