0

I need to apply a git word diff that treats every character as a word except when the characters are surrounded by square brackets. In that case, I want everything in the square brackets (even whitespace), including the brackets themselves and what they replace to be considered whole words so that none of these things are ever broken up.

Per the docs, "--word-diff-regex=. will treat each character as a word [...]". So far so good, but I haven't been able to combine this with my other requirement of never breaking up brackets etc.

Here's a screenshot of the problem:

enter image description here

Since the letter 'e' appears both in the words 'The' and 'future', it's being reused and not marked as a change. I believe this is a result of using the regular expression .. At the end, however, where only the letter 's' in 'possibilities' is highlighted as opposed to the entire word being replaced, that regular expression does the desired job.

The whole thing should look like this:

enter image description here

Here, both the brackets and what they replace are being treated as cohesive units, and the word 'possibilities' at the end is still not, which is perfect.

I have played with various regular expressions, including using XOR, to no avail. My guess is that, in many of my attempts, . 'swallows' whatever limiting expression I combine it with. I have gotten the specific example above to work with [a-zA-Z0-9\[]]|\s|\\n|[^[:space:]], but I don't know why (regex noob) and it doesn't work in other scenarios.

Keep in mind that git uses "POSIX “extended” regular expressions and not PCRE or Perl Compatible Regular Expressions, e.g. [:space:] instead of \s for the whitespace character class."

Dennis Hackethal
  • 13,662
  • 12
  • 66
  • 115
  • `--word-diff-regex='\[[^]]*\]?|.'`? – jthill Nov 17 '22 at 21:52
  • @jthill No, that has the same effect as simply doing `.` EDIT: Leaving out `|.` gives me only one huge addition. – Dennis Hackethal Nov 17 '22 at 22:08
  • Works for me, you can c&p my testcase from the answer – jthill Nov 17 '22 at 22:15
  • @jthill Silly me forgot to escape the escape in a string. For anyone else reading this comment, that means the regex in my q was already f*cked. – Dennis Hackethal Nov 18 '22 at 01:30
  • That's why you use the plain single quotes unless you want substitutions. Doublequotes will do some escapes and expansions, single quotes take the innards byte-for-byte. – jthill Nov 18 '22 at 02:31
  • That wasn't the issue in this case – it was that the entire git command was wrapped in Ruby string, and the escaping affected that string. Outside of that, the double quotes produce the same result for me. But I've changed it to single quotes in case this does come back to haunt me after making some changes in the future. – Dennis Hackethal Nov 18 '22 at 02:41

1 Answers1

3
$ sh -x <<\EOD; rm -rf test
git init test; cd $_
echo The possibilities > test; git add .; git commit -m-
sed -i 's,The,[Our future],' test; git commit -am-
git show --oneline --word-diff-regex=.
git show --oneline --word-diff-regex='\[[^]]*\]?|.'
EOD
+ git init test
Initialized empty Git repository in /home/jthill/sandbox/test/test/.git/
+ cd test
+ echo The possibilities
+ git add .
+ git commit -m-
[master (root-commit) 06604d0] -
 1 file changed, 1 insertion(+)
 create mode 100644 test
+ sed -i 's,The,[Our future],' test
+ git commit -am-
[master 6728cd4] -
 1 file changed, 1 insertion(+), 1 deletion(-)
+ git show --oneline --word-diff-regex=.
6728cd4 (HEAD -> master) -
diff --git a/test b/test
index c6eb735..1187549 100644
--- a/test
+++ b/test
@@ -1 +1 @@
[-Th-]{+[Our futur+}e{+]+} possibilities
+ git show --oneline '--word-diff-regex=\[[^]]*\]?|.'
6728cd4 (HEAD -> master) -
diff --git a/test b/test
index c6eb735..1187549 100644
--- a/test
+++ b/test
@@ -1 +1 @@
[-The-]{+[Our future]+} possibilities
jthill
  • 55,082
  • 5
  • 77
  • 137