locals.texi

locals.texi

[Nick Roberts]

Here's an update to the list of buffer local variables.  Most are new to Emacs
22 (fill-prefix and font-lock-defaults are two exceptions.  I guess the notion
of standard is a bit arbitrary but I've roughly assumed if that if it's
mentioned in the manual then it's standard.  If some of the variables that
I've added aren't appropriate then I'll move then to the @ignore section at
the end so that, in future, everyone can see that their omission is deliberate.

To clarfiy the concept of buffer local variables for myself:

In gdb-ui.el (as in many other files, I often just copy current practice), I
have constructs like

  (set (make-local-variable 'font-lock-defaults)
       '(gdb-memory-font-lock-keywords))

but I could just do

  (setq font-lock-defaults '(gdb-memory-font-lock-keywords))

?

-- 
Nick                                           http://www.inet.net.nz/~nickrob


*** locals.texi	07 Feb 2006 10:14:44 +1300	1.23
--- locals.texi	29 Jun 2006 10:35:36 +1200	
*************** mode variables will not be listed here.
*** 65,70 ****
--- 65,73 ----
  @item buffer-offer-save
  @xref{Killing Buffers}.
  
+ @item buffer-save-without-query
+ @xref{Killing Buffers}.
+ 
  @item buffer-read-only
  @xref{Read Only Buffers}.
  
*************** mode variables will not be listed here.
*** 86,91 ****
--- 89,97 ----
  @item cursor-type
  @xref{Cursor Parameters}.
  
+ @item cursor-in-non-selected-windows
+ @xref{Basic Windows}.
+ 
  @item comment-column
  @xref{Comments,,, emacs, The GNU Emacs Manual}.
  
*************** Does not work yet.
*** 109,114 ****
--- 115,132 ----
  @item fill-column
  @xref{Margins}.
  
+ @item fill-prefix
+ @xref{Margins}.
+ 
+ @item font-lock-defaults
+ @xref{Font Lock Basics}.
+ 
+ @item fringe-cursor-alist
+ @xref{Fringe Cursors}.
+ 
+ @item fringe-indicator-alist
+ @xref{Fringe Indicators}.
+ 
  @item fringes-outside-margins
  @xref{Fringes}.
  
*************** Used for communication between mouse com
*** 172,177 ****
--- 190,198 ----
  @item right-margin-width
  @xref{Display Margins}.
  
+ @item save-buffer-coding-system
+ @xref{Encoding and I/O}.
+ 
  @item scroll-bar-width
  @xref{Scroll Bars}.
  
*************** Used for communication between mouse com
*** 195,202 ****
--- 216,238 ----
  
  @item vertical-scroll-bar
  @xref{Scroll Bars}.
+ 
+ @item window-size-fixed
+ @xref{Resizing Windows}.
+ 
+ @item write-contents-functions
+ @xref{Saving Buffers}.
  @end table
  
  @ignore
+ Buffer local variables mentioned in manual but not considered worth
+ mentioning here:
+ 
+ left-fringe-width
+ right-fringe-width
+ @end ignore
+ 
+ 
+ @ignore
     arch-tag: 6baae835-b667-4447-91e2-9829ae1cf543
  @end ignore

Re: locals.texi

[Richard Stallman]

    In gdb-ui.el (as in many other files, I often just copy current practice), I
    have constructs like

      (set (make-local-variable 'font-lock-defaults)
	   '(gdb-memory-font-lock-keywords))

1. It is always cleaner to use separate calls to make-local-variable
   and setq.

2. When the variable is automatically local, it is ok to
   delete the call to make-local-variable.  A major mode
   normally doesn't set any variable that isn't local.

Re: locals.texi

[Stefan Monnier]

>       (set (make-local-variable 'font-lock-defaults)
> 	   '(gdb-memory-font-lock-keywords))

> 1. It is always cleaner to use separate calls to make-local-variable
>    and setq.

That's not true.  *You* may always find it cleaner, but it's far from
a general truth.  E.g. I strongly prefer to keep the two together (actually
I'd like to introduce a setq-local macro for it).


        Stefan

Re: locals.texi

[Richard Stallman]

    > 1. It is always cleaner to use separate calls to make-local-variable
    >    and setq.

    That's not true.  *You* may always find it cleaner, but it's far from
    a general truth.

I think that separate calls are always cleaner.
You're entitled to your opinion, of course.

Re: locals.texi

[Nick Roberts]

Richard Stallman writes:
 >     > 1. It is always cleaner to use separate calls to make-local-variable
 >     >    and setq.
 > 
 >     That's not true.  *You* may always find it cleaner, but it's far from
 >     a general truth.
 > 
 > I think that separate calls are always cleaner.
 > You're entitled to your opinion, of course.

I guess if the make-local-variable and setq get separated then it might
not be immediately obvious that the variable is buffer-local.

However, my original question was that with a variable like
font-lock-defaults, that automatically becomes buffer-local in each buffer, I
presumably don't need to use make-local-variable at all?

-- 
Nick                                           http://www.inet.net.nz/~nickrob

Re: locals.texi

[Richard Stallman]

    However, my original question was that with a variable like
    font-lock-defaults, that automatically becomes buffer-local in each buffer, I
    presumably don't need to use make-local-variable at all?

Yes.

Re: locals.texi

[Stefan Monnier]

> However, my original question was that with a variable like
> font-lock-defaults, that automatically becomes buffer-local in each buffer, I
> presumably don't need to use make-local-variable at all?

That's only true if you're 100% sure that the call to
make-variable-buffer-local will always have been made before your code runs.

In the case of font-lock-defaults it's currently true (since it's in
font-core.el which is preloaded), but it wasn't true in older Emacsen.


        Stefan