GNU bug report logs - #13609
24.2.92; completion-list-insert-choice-function

Previous Next

Full log

View this message in rfc822 format

From: help-debbugs <at> gnu.org (GNU bug Tracking System)
To: "Roland Winkler" <winkler <at> gnu.org>
Cc: tracker <at> debbugs.gnu.org
Subject: bug#13609: closed (24.2.92; completion-list-insert-choice-function)
Date: Sun, 03 Feb 2013 15:48:02 +0000

[Message part 1 (text/plain, inline)]

Your message dated Sun, 3 Feb 2013 09:46:49 -0600
with message-id <20750.34409.832682.449021 <at> gargle.gargle.HOWL>
and subject line Re: bug#13609: 24.2.92; completion-list-insert-choice-function
has caused the debbugs.gnu.org bug report #13609,
regarding 24.2.92; completion-list-insert-choice-function
to be marked as done.

(If you believe you have received this mail in error, please contact
help-debbugs <at> gnu.org.)


-- 
13609: http://debbugs.gnu.org/cgi/bugreport.cgi?bug=13609
GNU Bug Tracking System
Contact help-debbugs <at> gnu.org with problems

[Message part 2 (message/rfc822, inline)]

From: "Roland Winkler" <winkler <at> gnu.org>
To: bug-gnu-emacs <at> gnu.org
Subject: 24.2.92; completion-list-insert-choice-function
Date: Sat, 02 Feb 2013 10:24:57 -0600

The default value of completion-list-insert-choice-function
is completion--replace.  The `--' in the name of completion--replace
suggests to me that this is an internal function other code
should not rely on.  Yet isn't it a common scenario to bind
completion-list-insert-choice-function to a function which
calls completion--replace, plus it does something else?
(This is what bbdb-complete-mail does in BBDB v3.)

So I suggest to rename completion--replace to completion-replace
to make it clear that other code may use this function.
(Or solve this problem in some other way that other code may rely upon.)


In GNU Emacs 24.2.92.1 (x86_64-unknown-linux-gnu, GTK+ Version 2.20.1)
 of 2013-01-10 on regnitz
Windowing system distributor `The X.Org Foundation', version 11.0.10706000
System Description:	Ubuntu 10.04.4 LTS

[Message part 3 (message/rfc822, inline)]

From: "Roland Winkler" <winkler <at> gnu.org>
To: Stefan Monnier <monnier <at> iro.umontreal.ca>
Cc: 13609-done <at> debbugs.gnu.org
Subject: Re: bug#13609: 24.2.92; completion-list-insert-choice-function
Date: Sun, 3 Feb 2013 09:46:49 -0600

On Sun Feb 3 2013 Stefan Monnier wrote:
> > So I suggest to rename completion--replace to completion-replace
> > to make it clear that other code may use this function.
> 
> No, because some other package may already have changed
> completion-list-insert-choice-function, so you should really read the
> current value of completion-list-insert-choice-function, and then call
> that (via `funcall') rather than hard-coding completion--replace.

Thank you, that makes sense, it solves my problem.

Possibly, such a strategy could even be mentioned in the docstring of
completion-list-insert-choice-function.  How about adding the
following sentences?

  If you want to bind this variable to a function calling the default
  value of this variable as part of its job, do not hard-code this value
  in your code as it may change in future versions of Emacs.
  Instead, read the current value of completion-list-insert-choice-function,
  then call that via `funcall'.

Of course, this is a generic issue with any foo-function variables
that come with a default.  Merely, I do not know where to put such
a more generic remark into the elisp manual so that you find it
when you need it.

> > (Or solve this problem in some other way that other code may rely upon.)
> 
> As a matter of fact there's a new feature in trunk that does just that:
> `add-function'.

Great, though I'll keep this for future versions of BBDB.  Right now
I want to keep BBDB 3 compatible with GNU Emacs 23 and 24.
(Sometimes this is hard when you have to ignore cool new stuff...)

Roland

Previous Next

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