From: Ken Raeburn <raeburn@raeburn.org>
To: Daniel Colascione <daniel@censorshipresearch.org>
Cc: Emacs development discussions <emacs-devel@gnu.org>
Subject: Re: [PATCH] use tail pointer for LOOP (Was: Re: O(N^2) behavior in LOOP)
Date: Sat, 29 May 2010 20:45:28 -0400 [thread overview]
Message-ID: <9718A5AD-7A74-470B-A32D-DA14266506A3@raeburn.org> (raw)
In-Reply-To: <4C01AA28.6030002@censorshipresearch.org>
On May 29, 2010, at 19:58, Daniel Colascione wrote:
> We do this only for the anonymous-variable case, but it's still an
> improvement.
If it's only in the anonymous case, where (if I understand correctly) the value isn't accessible until the loop construct returns a value, why not keep it simple and build the list in reverse, doing an nreverse call at the end? It doesn't need to be "in order" in the intermediate states. Is it any faster to build the list in order? (Simply avoiding nreverse obviously makes things a little faster, but are you doing more work each time around the loop to maintain and use the tail pointer?)
Ken
next prev parent reply other threads:[~2010-05-30 0:45 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 [this message]
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
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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