Whitespace search and regex.c

[Stefan Monnier]

What is this recent change to regex.c w.r.t whitespace search all about?
This is really ugly.

As best as I can tell, this is to avoid the problem where
(replace-regexp-in-string " " "\\(?:\s-+\\)" ...) does not give the right
result because the " " could be inside brackets.

I think that changing regex.c for this one special case is a mistake.
Not only because it dirties up the regex.[ch] abstraction even further by
adding yet a bit more Emacs specific code in regex.[ch].

After all this problem manifests itself at a few other places (such as
regexp-opt-depth) as well.  So I think a more general solution would be much
more useful and cleaner.  E.g. a function (parse-partial-regex REGEXP POS)
which would return a value indicating whether POS is within brackets or not.


        Stefan