Re: c-style-alist

[Andrea Crotti <andrea.crotti.0@gmail.com>]

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?