I'm trying to match the following text:
void foo( int xxx,
int const & xxx,
With the regex:
\(\s-+\)[^\s-]+,$
IE: match whitespace, followed by non-whitespace, followed by a single comma at the end of the line
Expected matches:
[space]xxx, (line 1)
[space]xxx, (line 2)
Actual matches:
[space]foo( int xxx, (line 1)
[space]& xxx, (line 2)
Why is emacs matching the spaces midstring even though I've specified 'no space'?
The character alternative, [^\s-] matches anything other than \, s, and -.
See "[ ... ]" in C-h i g (elisp) Regexp Special RET.
Instead of that, you want to use \S- (upper-case) as the inverse of \s-
(C-h i g (elisp) Regexp Backslash RET).
Or, if you still want/need a character alternative, use character classes
(C-h i g (elisp) Char Classes RET).
It's because you have not anchored the regexp to the beginning of the line. So in your two later cases:
[space]foo([space]int[space]xxx, (line 1)
[space]&[space]xxx, (line 2)
It simply matches [space]xxx,.
Try ^\(\s-+\)[^\s-]+,$ (or, when written as an Emacs Lisp string: "^\\(\\s-+\\)[^\\s-]+,$")
