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From: xah lee <xahlee@gmail.com>
To: Stefan Monnier <monnier@iro.umontreal.ca>
Cc: Geoff Gole <geoffgole@gmail.com>, emacs-devel@gnu.org
Subject: Re: Idempotency of add-hook wrt lambda expressions
Date: Wed, 4 Mar 2009 12:13:08 -0800	[thread overview]
Message-ID: <aa6b5cbe0903041213s3df9d4c8h5c6a936aee8ffb16@mail.gmail.com> (raw)
In-Reply-To: <jwveixd5q69.fsf-monnier+emacs@gnu.org>

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On Wed, Mar 4, 2009 at 6:18 AM, Stefan Monnier <monnier@iro.umontreal.ca>wrote:

> > Say a file contains an add-hook form with a lambda argument:
> >   (add-hook 'foo-mode (lambda () (bar)))
> > Annoyingly, the function will be added to the hook twice if the file
> > is byte compiled, loaded, then reevaluated (such as with eval-buffer).
>
> As a general rule, you should not put a lambda but a function name
> (i.e. a symbol) instead, to avoid all those problems (and be able to
> replace the function with a newer version of it).  But occasionally
> a lambda is really exactly what you want, of course.
>

i prefer this be transparent to the user as Geoff Gole suggested.

My reason is that from a user point of view, lambda serves the same purpose
as function name, and one less thing to worry about problems that might come
from byte compiling.

if the code suggested does fix this without any other problems,  why not?

cheers,

  Xah

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  reply	other threads:[~2009-03-04 20:13 UTC|newest]

Thread overview: 24+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2009-03-04 12:10 Idempotency of add-hook wrt lambda expressions Geoff Gole
2009-03-04 14:18 ` Stefan Monnier
2009-03-04 20:13   ` xah lee [this message]
2009-03-04 21:23     ` Stefan Monnier
2009-03-04 21:27       ` Lennart Borgman
2009-03-05 17:22         ` M Jared Finder
2009-03-04 21:00   ` David Reitter
2009-03-05  1:27     ` Stephen J. Turnbull
2009-03-05  1:54     ` Stefan Monnier
2009-03-05  8:23       ` Geoff Gole
2009-03-05  9:49         ` David Kastrup
2009-03-05 11:41           ` tomas
2009-03-05 11:53           ` Geoff Gole
2009-03-05 16:45             ` Alan Mackenzie
2009-03-05 16:33               ` Helmut Eller
2009-03-05 16:38               ` Stefan Monnier
2009-03-05 16:50               ` Geoff Gole
2009-03-05 16:38           ` Alan Mackenzie
2009-03-05 20:44           ` Reiner Steib
2009-03-05 20:59             ` Edward O'Connor
2009-03-05 21:08               ` Reiner Steib
2009-03-06  9:36                 ` David Kastrup
2009-03-05 16:12 ` Alan Mackenzie
2009-03-05 16:37   ` Stefan Monnier

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