GNU bug report logs - #812
frame-local-variable documentation

Previous Next

To add a comment to this bug, you must first unarchive it, by sending
a message to control AT debbugs.gnu.org, with unarchive 812 in the body.
You can then email your comments to 812 AT debbugs.gnu.org in the normal way.

Toggle the display of automated, internal messages from the tracker.

Message #5 received at submit <at> emacsbugs.donarmstrong.com (full text, mbox):

From: Nikolaj Schumacher <me <at> nschum.de>
To: bug-gnu-emacs <at> gnu.org
Subject: frame-local-variable documentation
Date: Thu, 28 Aug 2008 23:23:21 +0200

As far as I can tell frame-local variables have been (or are about to
be) removed and currently don't work.  Given that, I find the
documentation slightly misleading.

`modify-frame-parameters' still contains this paragraph:

> The value of frame parameter FOO can also be accessed
> as a frame-local binding for the variable FOO, if you have
> enabled such bindings for that variable with
> `make-variable-frame-local'.

That should be removed, I think.


`make-variable-frame-local' has this note:

> This function is obsolete since 22.2;
> use a frame-parameter instead.

I think those two carry the notion that it's still possible to access a
frame-parameter as a variable, just by using modify-frame-parameters.

The explanation in the NEWS file is more clear in this regard:

> They can easily be emulated.  Rather than calling
> `make-variable-frame-local' and accessing the variable value directly,
> explicitly check for a frame-parameter


But I think removing the first one should avoid any confusion.


regards,
Nikolaj Schumacher

Message #8 received at 812 <at> emacsbugs.donarmstrong.com (full text, mbox):

From: Glenn Morris <rgm <at> gnu.org>
To: Nikolaj Schumacher <me <at> nschum.de>
Cc: 812 <at> debbugs.gnu.org
Subject: Re: bug#812: frame-local-variable documentation
Date: Sat, 30 Aug 2008 18:56:55 -0400

Nikolaj Schumacher wrote:

> As far as I can tell frame-local variables have been (or are about to
> be) removed and currently don't work.

They haven't been removed and will still be in 23.1, except:
"Variables cannot be both buffer-local and frame-local any more."

However, something seems broken. This works as it should:

emacs -Q
(setq foo 'bar)

(make-variable-frame-local 'foo)
     ; [1]
(set-frame-parameter nil 'foo t)

foo  ; -> t [2]

(make-frame)

foo  ; -> bar in new frame, still t in old frame [3]


If you add an extra evaluation of `foo' at point [1] (after making it
frame local, but before adding a frame parameter), then at point [2]
you get 'bar rather than t. After you make a new frame, it starts
working (at [3]).

> `modify-frame-parameters' still contains this paragraph:
>
>> The value of frame parameter FOO can also be accessed
>> as a frame-local binding for the variable FOO, if you have
>> enabled such bindings for that variable with
>> `make-variable-frame-local'.
>
> That should be removed, I think.

I mentioned it's obsolete.

> `make-variable-frame-local' has this note:
>
>> This function is obsolete since 22.2;
>> use a frame-parameter instead.

I tweaked it.

Previous Next

GNU bug tracking system
Copyright (C) 1999 Darren O. Benham, 1997,2003 nCipher Corporation Ltd, 1994-97 Ian Jackson.