questions about the value of local variables

questions about the value of local variables

[Hongxu Chen]

Hi,

  I am using Emacs for some C/C++ coding.

  One of the problem I am facing is that I need to specify some value of
  Emacs variables in the .dir-locals.el file so that I can make the
  programming environment much easier, one of which is
  `ffap-c-path'. Since I also need the default value , I hope I can
  append it rather that `setq'(like the default behavior of
  `.dir-locals.el'). But I just cannot figure how. May be I need to use
  `eval'?

  Another problem is that the file local variables I set cannot take
  effect before I type `M-x normal-mode', and for dir local variables it
  seems that I need to kill all the buffers who is inside the
  directory. So it there any easier way to do this?

  Still another question, is there any good practice to set the
  variables with proper hooks in c family programming language modes?
  There seems quite a lot of hooks there
  (`c-initialization-hook',`cc-mode-hook', `c-mode-hook',
  `c-mode-common-hook', etc) and I just get lost.
  

-- 
Regards,
Hongxu Chen

Re: questions about the value of local variables

[Alan Mackenzie]

Hongxu Chen <leftcopy.chx@gmail.com> wrote:

> Hi,

>  I am using Emacs for some C/C++ coding.

[ .... ]

>  Still another question, is there any good practice to set the
>  variables with proper hooks in c family programming language modes?
>  There seems quite a lot of hooks there
>  (`c-initialization-hook',`cc-mode-hook', `c-mode-hook',
>  `c-mode-common-hook', etc) and I just get lost.
>  

Well, I don't think there's a `cc-mode-hook', but the others exist,
yes.  :-)

Basic rule: put (the bulk of) your CC Mode customisations on
`c-mode-common-hook'.  If this doesn't work, you'll need one of the other
hooks.  It's all documented on page "CC Hooks" in the CC Mode manual.

> -- 
> Regards,
> Hongxu Chen

-- 
Alan Mackenzie (Nuremberg, Germany).

Re: questions about the value of local variables

[Hongxu Chen]

Alan Mackenzie <acm@muc.de> writes:

> Hongxu Chen <leftcopy.chx@gmail.com> wrote:
>
>> Hi,
>
>>  I am using Emacs for some C/C++ coding.
>
> [ .... ]
>
>>  Still another question, is there any good practice to set the
>>  variables with proper hooks in c family programming language modes?
>>  There seems quite a lot of hooks there
>>  (`c-initialization-hook',`cc-mode-hook', `c-mode-hook',
>>  `c-mode-common-hook', etc) and I just get lost.
>>  
>
> Well, I don't think there's a `cc-mode-hook', but the others exist,
> yes.  :-)
Sorry that I made a mistake.
>
> Basic rule: put (the bulk of) your CC Mode customisations on
> `c-mode-common-hook'.  If this doesn't work, you'll need one of the other
> hooks.  It's all documented on page "CC Hooks" in the CC Mode manual.
Thanks for your advice. It seems that using the right hook really needs
quite a lot of tricks. A few days ago I was adding a keymap for one of
the command, but it didn't work until I use the
`c-initialization-hook'. Well, seems that I have to read the docs
first. 
>
>> -- 
>> Regards,
>> Hongxu Chen

-- 
Regards,
Hongxu Chen