Re: c-style-alist

["Andreas Röhler" <andreas.roehler@easy-emacs.de>]

Am 25.09.2010 13:54, schrieb Andrea Crotti:
> Andrea Crotti<andrea.crotti.0@gmail.com>  writes:
>
>> Supposing I have a new language (actually NED), and I already have some
>> syntax highlighting.
>>
>> The only thing I want to add is a smarter indentation, and for that is
>> quite similar to C++.
>>
>> Looking for possible answers I found out that in
>> c-style-alist there is also for example python-mode, which is not a
>> c-mode derivatives.
>>
>> Is that is the general way to define the correct the policy of spacing?
>> And what if I define it as a derived mode even if it's quite different
>> from the original c/c++ branch?
>
> I solved  making that mode a derived-mode from cc-mode.
> Then I created another derived-mode for c++ files used by omnetpp, but
> I'm struggling to make it automatically enabled.
>
> It's very very simple
> --8<---------------cut here---------------start------------->8---
> (require 'derived)
>
> (define-derived-mode cpp-omnet-mode c++-mode "C++ Omnet mode"
>    "Major mode for editing c++ files used with omnet++"
>    )
>
> (provide 'cpp-omnet-mode)
> --8<---------------cut here---------------end--------------->8---
>
> and I thought I could do simply something like
> --8<---------------cut here---------------start------------->8---
>    ;; Look for the file .ini or the header inclusion
>    (defun is-omnet-cpp-file ()
>      (if
>          (or (file-exists-p "omnetpp.ini")
>              (search-forward "<omnetpp.h>"))
>          (cpp-omnet-mode)))
>
>    ;FIXME: Not working correctly yet, because it goes in infinite loop
>    ;; (add-hook 'c++-mode-hook 'is-omnet-cpp-file)
> --8<---------------cut here---------------end--------------->8---
>
> But it's not fine, since it will evaluate infinitely this hook.
> Another possibility would be to use "find-file-hook", but it doesn't
> really make sense because the files possible are a subset of c++ files.
>
> How can I make it non recurse keeping this?
> Or some other suggestions?
>
>
>

Maybe like this:

(defun is-omnet-cpp-file ()
   (or (cpp-omnet-mode)
       (if
           (or (file-exists-p "omnetpp.ini")
               (search-forward "<omnetpp.h>"))
           (cpp-omnet-mode))))

There is no path with "omnetpp.ini", which however should not cause a 
infinite.


Andreas

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