From: Tassilo Horn <tsdh@gnu.org>
To: help-gnu-emacs@gnu.org
Subject: Re: Concern around use of eval
Date: Thu, 19 Mar 2015 09:31:17 +0100 [thread overview]
Message-ID: <87d2458k2y.fsf@gnu.org> (raw)
In-Reply-To: <slrnmgl16k.6n4.joost.m.kremers@j.kremers4.news.arnhem.chello.nl> (Joost Kremers's message of "19 Mar 2015 08:12:04 GMT")
Joost Kremers <joost.m.kremers@gmail.com> writes:
> Why not do it at the top level directly? E.g.:
>
> ,----
> | (defvar lh/labels '("label1" "label2" "label3"))
> |
> | (defmacro lh/gen-predicate (label)
> | `(defun ,(intern (concat "lh/" label "-p")) ()
> | (member ,label *lh/system-label-store*)))
> |
> | (mapc (lambda (label)
> | (lh/gen-predicate label))
> | lh/labels)
> `----
That won't work because. When reading the mapc form, emacs sees that
`lh/gen-predicate' is a macro and tries to expand it with the symbol
label as argument. The macroexpansion takes place before the actual
execution of the code.
Bye,
Tassilo
next prev parent reply other threads:[~2015-03-19 8:31 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-03-19 6:53 Concern around use of eval Les Harris
2015-03-19 8:00 ` Tassilo Horn
[not found] ` <mailman.2302.1426752018.31049.help-gnu-emacs@gnu.org>
2015-03-19 8:12 ` Joost Kremers
2015-03-19 8:31 ` Tassilo Horn [this message]
[not found] ` <mailman.2305.1426753885.31049.help-gnu-emacs@gnu.org>
2015-03-20 19:54 ` Joost Kremers
2015-03-19 14:07 ` Stefan Monnier
2015-03-20 15:17 ` Thierry Volpiatto
2015-03-20 17:19 ` Bug in Elisp font-locking (was: Concern around use of eval) Tassilo Horn
2015-03-20 17:31 ` Bug in Elisp font-locking Stefan Monnier
2015-03-20 17:43 ` Drew Adams
2015-03-20 18:47 ` Tassilo Horn
2015-03-20 20:38 ` Stefan Monnier
2015-03-20 22:45 ` Tassilo Horn
2015-03-21 2:33 ` Stefan Monnier
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