Re: Understanding and improving --word-diff

On 08/11/2010, at 16:16, Matthijs Kooijman wrote:

Hi folks,

I recently discovered --word-diff (or rather, --color-words and found
--word-diff when I started to hack on the git master version) and I had
hoped it would make the unified diffs generated by git-diff more
readable.

[snip]

Inexact output
--------------
Secondly, the --word-diff output currently never displays any changes to
the non-word (whitespace) parts of a file. This makes sense for the
LaTeX case, but sometimes you might want to get exact diff output
instead. At first glance this seems possible by specifiying a word-regex
of "." or something similar (i.e., make sure that the word regex matches
everything). But this is problematic for newlines. The documentation
states that stuff gets silently ignored if a newline ends up inside a
word. For the --word-diff=color format, this is probably a fixed
limitation of the otput format: you can't give a color to a newline (or
a space, for that matter).

[snip]

Porcelain format
----------------
Lastly, the "porcelain" word-diff format seems a bit weird to me. Is
the format specified somewhere, or are there any programs that use it
currently? I couldn't find any users inside the git.git tree itself?

Looking at the format itself, it's a bit unclear to me what the ~ lines
mean exactly. Commit 882749, which introduced the format says the mean
"newlines in the input", but I'm not sure if this means the old file,
new file or both.

I posted along similar lines back in September:

  http://article.gmane.org/gmane.comp.version-control.git/156375

I found I couldn't really use the porcelain format due to information loss and ended up having to roll my own, parse the normal diff output and using that.

Cheers,
Wincent