default-FOO variables

default-FOO variables

[Eli Zaretskii]

What does this entry in NEWS:

   ** All the default-FOO variables that hold the default value of the FOO
   variable, are now declared obsolete.

mean for variable declaration in C such as this:

     DEFVAR_LISP_NOPRO ("default-enable-multibyte-characters",
			&buffer_defaults.enable_multibyte_characters,
			doc: /* *Default value of `enable-multibyte-characters' for buffers not overriding it.
   This is the same as (default-value 'enable-multibyte-characters).  */);

Do we need to avoid such declarations?  If so, how to do the
equivalent of that for buffer-local variables defined in C?

Re: default-FOO variables

[Stefan Monnier]

> What does this entry in NEWS:
>    ** All the default-FOO variables that hold the default value of the FOO
>    variable, are now declared obsolete.

> mean for variable declaration in C such as this:

>      DEFVAR_LISP_NOPRO ("default-enable-multibyte-characters",
> 			&buffer_defaults.enable_multibyte_characters,
> 			doc: /* *Default value of `enable-multibyte-characters' for buffers not overriding it.
>    This is the same as (default-value 'enable-multibyte-characters).  */);

> Do we need to avoid such declarations?

Yes, the aim is to get rid of them at some point.

> If so, how to do the equivalent of that for buffer-local variables
> defined in C?

I don't understand, why you'd need something equivalent.
Can you give us some details?


        Stefan

Re: default-FOO variables

[Eli Zaretskii]

> From: Stefan Monnier <monnier@iro.umontreal.ca>
> Cc: emacs-devel@gnu.org
> Date: Mon, 05 Oct 2009 09:39:37 -0400
> 
> >      DEFVAR_LISP_NOPRO ("default-enable-multibyte-characters",
> > 			&buffer_defaults.enable_multibyte_characters,
> > 			doc: /* *Default value of `enable-multibyte-characters' for buffers not overriding it.
> >    This is the same as (default-value 'enable-multibyte-characters).  */);
> 
> > Do we need to avoid such declarations?
> 
> Yes, the aim is to get rid of them at some point.
> 
> > If so, how to do the equivalent of that for buffer-local variables
> > defined in C?
> 
> I don't understand, why you'd need something equivalent.

Very simply, I need to add a new buffer-local variable.  The current
paradigm seems to be:

 . Add a DEFVAR_LISP_NOPRO for its default value.

 . Add a DEFVAR_PER_BUFFER for its buffer-local value.

 . Add one or 2 one-liners to init_buffer_once to initialize
   buffer_defaults and buffer_local_flags.

I'm asking what's the New Way of doing this?

Re: default-FOO variables

[Stefan Monnier]

>> >      DEFVAR_LISP_NOPRO ("default-enable-multibyte-characters",
>> > 			&buffer_defaults.enable_multibyte_characters,
>> > 			doc: /* *Default value of `enable-multibyte-characters' for buffers not overriding it.
>> >    This is the same as (default-value 'enable-multibyte-characters).  */);
>> 
>> > Do we need to avoid such declarations?
>> 
>> Yes, the aim is to get rid of them at some point.
>> 
>> > If so, how to do the equivalent of that for buffer-local variables
>> > defined in C?
>> 
>> I don't understand, why you'd need something equivalent.

> Very simply, I need to add a new buffer-local variable.  The current
> paradigm seems to be:

>  . Add a DEFVAR_LISP_NOPRO for its default value.

>  . Add a DEFVAR_PER_BUFFER for its buffer-local value.

>  . Add one or 2 one-liners to init_buffer_once to initialize
>    buffer_defaults and buffer_local_flags.

> I'm asking what's the New Way of doing this?

Same as before, just skip the step number 1.


        Stefan

Re: default-FOO variables

[Eli Zaretskii]

> From: Stefan Monnier <monnier@iro.umontreal.ca>
> Cc: emacs-devel@gnu.org
> Date: Mon, 05 Oct 2009 10:48:34 -0400
> 
> >  . Add a DEFVAR_LISP_NOPRO for its default value.
> 
> >  . Add a DEFVAR_PER_BUFFER for its buffer-local value.
> 
> >  . Add one or 2 one-liners to init_buffer_once to initialize
> >    buffer_defaults and buffer_local_flags.
> 
> > I'm asking what's the New Way of doing this?
> 
> Same as before, just skip the step number 1.

And what about the lines such as this:

   buffer_defaults.overwrite_mode = Qnil;

Should we skip these as well?

Re: default-FOO variables

[Stefan Monnier]

> And what about the lines such as this:
>    buffer_defaults.overwrite_mode = Qnil;
> Should we skip these as well?

No.  These are important because they set the (default-value 'foo).


        Stefan

Re: default-FOO variables

[Eli Zaretskii]

> From: Stefan Monnier <monnier@iro.umontreal.ca>
> Cc: emacs-devel@gnu.org
> Date: Tue, 06 Oct 2009 09:28:24 -0400
> 
> > And what about the lines such as this:
> >    buffer_defaults.overwrite_mode = Qnil;
> > Should we skip these as well?
> 
> No.  These are important because they set the (default-value 'foo).

Okay, thanks.