Re: spaces in isearch

[Juri Linkov <juri@jurta.org>]

Alex Schroeder <alex@emacswiki.org> writes:
> Juri Linkov <juri@jurta.org> writes:
>> Since C-q in isearch mode is processed by isearch-quote-char,
>> it could intercept SPC and insert [ ] into the search string.
>
> I'm not sure I like that.  C-q <something> should insert <something>,

No, C-q <something> should be used to insert <something_different>.
There is no sense to use C-q <something> to insert the same <something>.

> I didn't know about the special behaviour of <space> in
> isearch-forward-regexp.

The old behavior: SPC inserts \\(?:\\s-+\\), C-q SPC inserts SPC.
The new behavior: SPC inserts SPC (which now internally means \\(?:\\s-+\\)).

So C-q SPC inserting SPC has no sense anymore since SPC now is
inserted by SPC itself.

Moreover, to achieve backward compatibility for users using C-q SPC
to match just a space, C-q SPC should do something to preserve the
literal meaning of a space.  Adding [ ] to the search string in regexp
isearch mode is the most natural thing to do.

>From implementation point of view this means moving the old code from
`isearch-whitespace-chars' to `isearch-quote-char' and replacing

    (isearch-process-search-string search-whitespace-regexp " ")

with

    (isearch-process-search-string "[ ]" " ")

-- 
Juri Linkov
http://www.jurta.org/emacs/