From: Paul Rubin <no.email@nospam.invalid>
Subject: Re: Introductory Presentations, especially aimed at C++ programmers!
Date: Thu, 15 Dec 2016 23:41:00 -0800
Date: 2016-12-15T23:41:00-08:00 [thread overview]
Message-ID: <87a8bw1fub.fsf@nightsong.com> (raw)
In-Reply-To: o2uu9g$oq5$1@dont-email.me
"Jeffrey R. Carter" <spam.jrcarter.not@spam.not.acm.org> writes:
> list_length ([]) ->
> 0;
> list_length ([First | Rest]) ->
> 1 + list_length (Rest).
> is considered tail recursion and is required to be optimized away, so
> that's how I was using the term.
That's not tail recursion because after the recursive call, the result
has to be passed to +. You'd write it tail recursively something like:
list_length(X) -> go(X, 0).
go([], n) -> n;
go([First|Rest], n) -> go(Rest, n+1).
That lets the compiler transform the recursive call into a jump. I
don't remember the name of this trick of using an extra argument to make
something tail recursive, but it's idiomatic in functional programming.
next prev parent reply other threads:[~2016-12-16 7:41 UTC|newest]
Thread overview: 52+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-07-10 12:24 Introductory Presentations, especially aimed at C++ programmers! John McCabe
2009-07-10 21:49 ` jimmaureenrogers
2009-07-10 23:37 ` wwilson
2009-07-11 0:07 ` jimmaureenrogers
2009-07-12 4:00 ` wwilson
2009-07-11 8:15 ` Stephen Leake
2009-07-15 6:43 ` Jean-Pierre Rosen
2016-12-07 17:06 ` john
2016-12-07 17:44 ` Luke A. Guest
2016-12-07 18:35 ` Jeffrey R. Carter
2016-12-07 23:03 ` Randy Brukardt
2016-12-07 23:47 ` Jeffrey R. Carter
2016-12-08 0:08 ` Paul Rubin
2016-12-09 22:01 ` Randy Brukardt
2016-12-09 22:18 ` Jeffrey R. Carter
2016-12-13 0:53 ` Randy Brukardt
2016-12-13 3:21 ` Jeffrey R. Carter
2016-12-13 21:15 ` Robert A Duff
2016-12-13 22:05 ` Jeffrey R. Carter
2016-12-13 22:52 ` Robert A Duff
2016-12-14 0:02 ` Jeffrey R. Carter
2016-12-13 23:05 ` Randy Brukardt
2016-12-14 0:13 ` Jeffrey R. Carter
2016-12-14 22:48 ` Randy Brukardt
2016-12-15 0:00 ` Jeffrey R. Carter
2016-12-15 10:46 ` Maciej Sobczak
2016-12-16 7:37 ` Paul Rubin
2016-12-15 20:14 ` Niklas Holsti
2016-12-15 20:27 ` Jeffrey R. Carter
2016-12-15 21:04 ` Niklas Holsti
2016-12-15 21:40 ` Jeffrey R. Carter
2016-12-16 7:41 ` Paul Rubin [this message]
2016-12-13 22:50 ` Randy Brukardt
2016-12-14 0:08 ` Jeffrey R. Carter
2016-12-14 1:01 ` Shark8
2016-12-08 8:08 ` Maciej Sobczak
2016-12-08 8:38 ` Dmitry A. Kazakov
2016-12-08 10:25 ` Paul Rubin
2016-12-08 13:39 ` Maciej Sobczak
2016-12-09 1:30 ` Paul Rubin
2016-12-09 8:31 ` J-P. Rosen
2016-12-09 8:58 ` Paul Rubin
2016-12-09 9:18 ` J-P. Rosen
2016-12-09 9:27 ` Paul Rubin
2016-12-09 10:49 ` J-P. Rosen
2016-12-09 19:58 ` Jeffrey R. Carter
2016-12-09 8:35 ` G.B.
2016-12-09 8:57 ` Paul Rubin
2016-12-09 22:15 ` Randy Brukardt
2016-12-09 21:58 ` Randy Brukardt
2016-12-08 8:23 ` Maciej Sobczak
2016-12-08 18:54 ` Adam Jensen
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