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From: Emanuel Berg <embe8573@student.uu.se>
To: help-gnu-emacs@gnu.org
Subject: Re: never use `eval' (was: Re: How to mapcar or across a list?)
Date: Thu, 16 Jul 2015 01:57:43 +0200	[thread overview]
Message-ID: <87bnfd2cug.fsf@nl106-137-147.student.uu.se> (raw)
In-Reply-To: CAOj2CQSEn6=TFX2tJmsuinCgefMz5p1wMTr+0XOXxv7a7TzRSw@mail.gmail.com

John Mastro <john.b.mastro@gmail.com> writes:

> I would use something like this:
>
> (defmacro ...

Macros never liked me, and that is mutual. Are they
really preferrable to `eval'?

> For this (and others like it)

... which are? Do you mean the eval + backquote combo?

> it looks like you could instead simply use e.g.
> (apply #'create-book nil title data)

This is what it looks like:

    (eval `(create-book nil ,title ,@data))

With `apply', won't the last "data" be a list, i.e.

    (a b ... n)

instead of

    a b ... n

?

-- 
underground experts united
http://user.it.uu.se/~embe8573




  reply	other threads:[~2015-07-15 23:57 UTC|newest]

Thread overview: 21+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-07-15 20:14 How to mapcar or across a list? Marcin Borkowski
2015-07-15 20:42 ` Rasmus
2015-07-15 20:55   ` Marcin Borkowski
2015-07-15 22:21 ` Emanuel Berg
2015-07-15 22:21 ` John Mastro
     [not found] ` <mailman.6977.1436998965.904.help-gnu-emacs@gnu.org>
2015-07-15 22:28   ` Pascal J. Bourguignon
2015-07-15 22:36     ` Emanuel Berg
2015-07-15 22:57     ` never use `eval' (was: Re: How to mapcar or across a list?) Emanuel Berg
2015-07-15 23:27       ` John Mastro
2015-07-15 23:57         ` Emanuel Berg [this message]
2015-07-16  0:18           ` John Mastro
     [not found]         ` <mailman.6984.1437004760.904.help-gnu-emacs@gnu.org>
2015-07-16  0:04           ` Barry Margolin
     [not found]     ` <mailman.6982.1437001117.904.help-gnu-emacs@gnu.org>
2015-07-16  0:01       ` Barry Margolin
2015-07-16  1:13         ` Emanuel Berg
2015-07-17  0:55           ` Emanuel Berg
     [not found]           ` <mailman.7027.1437094623.904.help-gnu-emacs@gnu.org>
2015-07-17  1:39             ` never use `eval' Pascal J. Bourguignon
2015-07-17  2:16               ` Emanuel Berg
2015-07-17  8:36               ` Barry Margolin
2015-07-17  8:55                 ` Pascal J. Bourguignon
2015-07-16  0:22       ` Pascal J. Bourguignon
2015-07-16  1:11         ` Emanuel Berg

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