Re: isearch highlighting

[Juri Linkov]

Richard Stallman <address@hidden> writes:
>     If it's responsive enough, then it won't be interrupted by while-no-input.
>
> That is not entirely true.  If it spends even a tiny amount of time
> being busy, then it can sometimes be interrupted by while-no-input.
> So we would need to do the work to make it use while-no-input
> correctly, even if those cases are rather rare.

My tests show that those cases are not rare, especially with rapid
repeated presses of C-s.

> What does it need to do?  Any input character that triggers
> while-no-input will certainly be intepreted by the search command
> loop.  Most of the time, this will change the search string.

With the change of the search string it has nothing to do other than
removing all already highlighted overlays and starting the new
highlighting loop.  With an input character that doesn't modify
the search string (e.g. C-s) the case is more complicated: it
should remove a part of created highlighting overlays (that were
added in the current invocation of `isearch-lazy-highlight-update')
and to restore the previous values of isearch-lazy-highlight-start,
isearch-lazy-highlight-end, isearch-lazy-highlight-window-start,
isearch-lazy-highlight-window-end, isearch-lazy-highlight-wrapped,
and to restart the timer.

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