Re: hiding lines

[Andreas Roehler]

Alan Mackenzie wrote:
> Hi, Werner,
> 
> On Thu, Apr 02, 2009 at 08:52:01AM +0200, Werner LEMBERG wrote:
> 
>> Folks,
> 
> 
>> I would like to hide lines in a buffer which satisfy a regexp --
>> either the lines get completely hidden (or perhaps indicated with
>> `...' as in the outline mode), or a search-and-replace function
>> doesn't match them.
> 
>> Does Emacs have such a thing?  A lookup in the docs doesn't show
>> anything relevant.  This would be a very convenient function for
>> editing lists.
> 
> The following makes the current region invisible and intangible.  It
> doesn't, as yet, make it visible and tangible again very well.  It's not
> quite what you're asking for, but you can likely use it as the engine
> end of what you want.
> 
>     (defun make-region-invisible (beg end &optional arg)
>       "Make the current region invisible and intangible.
>     With a prefix arg, make it visible again.  With an arg of 0,
>     make all such regions visible."
>       (interactive "r\nP")
>       (let (ov ovs)
>         (cond
>          ((eq arg 0)
>           (setq ovs (overlays-in (point-min) (point-max)))
>           (mapc (lambda (o)
>                   (when (overlay-get o 'acm-invisible)
>                     (delete-overlay o)))
>                 ovs))
>          ((equal arg '(4))
>           (setq ovs (overlays-at (point)))
>           (mapc (lambda (o)
>                   (when (overlay-get o 'acm-invisible)
>                     (delete-overlay o)))
>                 ovs))
>          (t
>           (setq ov (make-overlay beg end))
>           (overlay-put ov 'acm-invisible t)
>           (overlay-put ov 'invisible t)
>           (overlay-put ov 'intangible t)))))
>     (global-set-key "\C-cz" 'make-region-invisible)
> 
> 
>>     Werner
> 

Thanks to Bastien Guerry Emacs-Lisp Bill-Board is
available for just that kind of tasks.

Please have have a look at http://repo.or.cz/w/elbb.git

The declared bill-board environment allows some
playing, even with git.


Andreas Röhler