From: Stefan Monnier <monnier@iro.umontreal.ca>
Subject: Re: Canonical add-hook idiom
Date: Sun, 16 Nov 2003 23:26:29 GMT [thread overview]
Message-ID: <jwvoevbucje.fsf-monnier+gnu.emacs.help@vor.iro.umontreal.ca> (raw)
In-Reply-To: GWitb.1387$n56.744@newsread1.news.pas.earthlink.net
> What is the preferred approach given these examples:
> 1). (add-hook 'some-mode-hook (lambda () [...]
> 2). (add-hook 'some-mode-hook '(lambda () [...]
> 3). (add-hook 'some-mode-hook (function (lambda () [...]
> 4). None of the above -- please explain.
The '(lambda form is to be avoided: the ' says "what follows
is pure data" whereas what follows is actually code, so it's
confusing (I expect humans won't get confused, but byte-compilers
do get confused).
`lambda' is a macro that expands to (function (lambda so the two are
pretty much interchangeable. As for #'(lambda, it is a shorthand
for (function (lambda.
I thus recommend (lambda since it's the shortest and ask people to stay away
from '(lambda since it poses problems to the byte-compiler (as well as to
other code-walkers such as some fancy CL macros (typically
`lexical-let')). But if you prefer #(lambda or (function (lambda,
that's OK: you won't burn in hell for it.
Stefan
prev parent reply other threads:[~2003-11-16 23:26 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2003-11-15 5:35 Canonical add-hook idiom Bob Nelson
2003-11-15 8:25 ` Oliver Scholz
2003-11-15 18:27 ` Henrik Enberg
2003-11-15 16:55 ` Jesper Harder
2003-11-16 23:26 ` Stefan Monnier [this message]
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