Re: VIM can recognize #if 0 #endif as comment pair, how to do that in Emacs?

[J. David Boyd]

"Leo.Hou" <leo.hou@gmail.com> writes:

> Hi Experts,
>
>
> I saw a friend using VIM and it recognizes #if 0 -- #endif as comment
> pair and use the comment color for the code in between!
>
> This is so cool because I had a big headache using emacs+etags jumping
> into others' code, spent 5 minutes and then realized that emacs
> brought me to some codes between a #if0 -- #endif pair. :'-(
>
> Can anyone make Emacs to recognize this common convention and
> highlight all the pieces between them as comment?
>
>
>
> Thanks!
>
> Leo

Not _exactly_ what you are talking about, but I like this:

>From C-h f hide-ifdef-mode

hide-ifdef-mode is an interactive autoloaded Lisp function in `hideif'.
(hide-ifdef-mode &optional arg)

Toggle Hide-Ifdef mode.  This is a minor mode, albeit a large one.
With arg, turn Hide-Ifdef mode on if arg is positive, off otherwise.
In Hide-Ifdef mode, code within #ifdef constructs that the C preprocessor
would eliminate may be hidden from view.  Several variables affect
how the hiding is done:

`hide-ifdef-env'
        An association list of defined and undefined symbols for the
        current buffer.  Initially, the global value of `hide-ifdef-env'
        is used.

`hide-ifdef-define-alist'
        An association list of defined symbol lists.
        Use `hide-ifdef-set-define-alist' to save the current `hide-ifdef-env'
        and `hide-ifdef-use-define-alist' to set the current `hide-ifdef-env'
        from one of the lists in `hide-ifdef-define-alist'.

`hide-ifdef-lines'
        Set to non-nil to not show #if, #ifdef, #ifndef, #else, and
        #endif lines when hiding.

`hide-ifdef-initially'
        Indicates whether `hide-ifdefs' should be called when Hide-Ifdef mode
        is activated.

`hide-ifdef-read-only'
        Set to non-nil if you want to make buffers read only while hiding.
        After `show-ifdefs', read-only status is restored to previous value.


Uses keymap "hide-ifdef-mode-map", which is not currently defined.