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From: Thien-Thi Nguyen <ttn@gnuvola.org>
To: tomas@tuxteam.de
Cc: emacs-devel@gnu.org
Subject: Re: [PATCH] use tail pointer for LOOP
Date: Thu, 17 Jun 2010 09:18:28 +0200	[thread overview]
Message-ID: <87mxuu5dq3.fsf@ambire.localdomain> (raw)
In-Reply-To: <20100617051021.GA26623@tomas> (tomas@tuxteam.de's message of "Thu, 17 Jun 2010 07:10:21 +0200")

() tomas@tuxteam.de
() Thu, 17 Jun 2010 07:10:21 +0200

   Still, reversing seems to be worth it (by some 30 percent).
   Unless we find some way to streamline the tail pointer better.

How does this variant fare?

(defun copy3 (lst)
  "Return a copy of LST."
  (let* ((box (list nil))
         (tp box))
    (while lst
      (setq tp (cdr (nconc tp (list (pop lst))))))
    (cdr box)))

thi



  reply	other threads:[~2010-06-17  7:18 UTC|newest]

Thread overview: 21+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2010-05-29 21:56 O(N^2) behavior in LOOP Daniel Colascione
2010-05-29 22:06 ` Daniel Colascione
2010-05-29 22:14   ` Lennart Borgman
2010-05-29 22:35   ` Geoff Gole
2010-05-29 23:58     ` [PATCH] use tail pointer for LOOP (Was: Re: O(N^2) behavior in LOOP) Daniel Colascione
2010-05-30  0:45       ` Ken Raeburn
2010-05-30  0:49         ` Daniel Colascione
2010-06-16 17:44           ` tomas
2010-06-16 18:10             ` [PATCH] use tail pointer for LOOP David Kastrup
2010-06-17  5:10               ` tomas
2010-06-17  7:18                 ` Thien-Thi Nguyen [this message]
2010-06-17  9:22                   ` tomas
2010-06-17 10:03                     ` Thien-Thi Nguyen
2010-06-17 14:05                       ` tomas
2010-06-17 15:16                         ` Thien-Thi Nguyen
2010-06-17 10:12                     ` Thien-Thi Nguyen
2010-06-17 20:48                 ` Stefan Monnier
2010-06-18  7:07                   ` David Kastrup
2010-06-18 13:40                     ` Stefan Monnier
2010-05-30 17:05       ` Štěpán Němec
2010-05-30 17:09         ` Daniel Colascione

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