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From: Thierry Volpiatto <thierry.volpiatto@gmail.com>
To: Florian Beck <abstraktion@t-online.de>
Cc: help-gnu-emacs@gnu.org
Subject: Re: Problem with position and find (cl)
Date: Sat, 21 Jun 2008 06:57:32 +0200	[thread overview]
Message-ID: <87abhf2xmr.fsf@thievol.homelinux.org> (raw)
In-Reply-To: <87abhfg0mn.fsf@sophokles.streitblatt.de> (Florian Beck's message of "Sat, 21 Jun 2008 01:14:24 +0200")

Florian Beck <abstraktion@t-online.de> writes:

> Thierry Volpiatto <thierry.volpiatto@gmail.com> writes:
>
>
>> position default test is 'eq, try 'equal
>
> Indeed, many cl-tests default to 'eq.
>
> BTW, what is the reason for this (apart from being a language convention)?
>
> When I try
>
> (let ((start-time (current-time)))
>   (dotimes (i 1000000)
>     (position '(1) '((2) (5) (2) 2 x  4 fer fer f r e wqf (1) fr r) :test 'eq))
>   (format-time-string "%S" (time-since start-time)))
>
> with 'eq and 'equal I get the same result. So 'eq is not more efficent,
> is it?
eq compare two objects and say if they are the same.
equal compare two objects and say if the value of these object is the
same.

,----
| ELISP> (setq A '(1 2))
| (1 2)
| 
| ELISP> (setq B '(1 2))
| (1 2)
| 
| ELISP> (eq A B)
| nil
| ELISP> (equal A B)
| t
`----

-- 
A + Thierry
Pub key: http://pgp.mit.edu




  parent reply	other threads:[~2008-06-21  4:57 UTC|newest]

Thread overview: 12+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2008-06-20 18:30 Problem with position and find (cl) Marc Tfardy
2008-06-20 19:58 ` Marc Tfardy
2008-06-20 20:14   ` Florian Beck
2008-06-20 21:24     ` Thierry Volpiatto
     [not found]     ` <mailman.13619.1213996704.18990.help-gnu-emacs@gnu.org>
2008-06-20 23:14       ` Florian Beck
2008-06-21  2:04         ` Barry Margolin
2008-06-21  4:31           ` Florian Beck
2008-06-21  4:57         ` Thierry Volpiatto [this message]
2008-06-21 10:07       ` Marc Tfardy
2008-06-21 10:38         ` Marc Tfardy
2008-06-21 12:38           ` Thierry Volpiatto
2008-06-20 21:16 ` Thien-Thi Nguyen

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