From: Pierre Chambart <pierre.chambart@laposte.net>
To: Goswin von Brederlow <goswin-v-b@web.de>, caml-list@inria.fr
Subject: Re: [Caml-list] Why List.map does not be implemented tail-recursively?
Date: Mon, 29 Sep 2014 16:02:11 +0200 [thread overview]
Message-ID: <54296663.8080902@laposte.net> (raw)
In-Reply-To: <20140929120817.GB20628@frosties>
On 29/09/2014 14:08, Goswin von Brederlow wrote:
> And I'll will do the same, reply anyway.
>
> You can't write List.map tail recursive unless:
>
> 1) You use List.rev (List.rev_map fn list).
>
> or
>
> 2) Use hacks to create a mutable list so you can grow it head to tail
> instead of tail to head.
>
> The fastest code seems to be when you do List.map recursively up to
> some limit (say 1000 items) and return the remainder. Repeat and glue
> the lists together into one large list using hacks.
>
> MfG
> Mrvn
>
Please, don't do that hack ! The compiler assumes immutable data are not
mutated and optimise knowing that.
--
Pierre
next prev parent reply other threads:[~2014-09-29 14:02 UTC|newest]
Thread overview: 25+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-09-28 19:31 Shuai Wang
2014-09-28 19:36 ` Gabriel Scherer
2014-09-28 19:45 ` Anthony Tavener
2014-09-29 12:08 ` Goswin von Brederlow
2014-09-29 14:02 ` Pierre Chambart [this message]
2014-09-29 15:44 ` Yaron Minsky
2014-09-29 21:00 ` Gabriel Scherer
2014-09-30 8:46 ` [Caml-list] Why List.map does not be implemented oleg
2014-09-30 9:07 ` Gabriel Scherer
2014-10-01 10:29 ` oleg
2014-10-01 12:00 ` Gerd Stolpmann
2014-10-29 10:11 ` Gabriel Scherer
2014-10-02 10:09 ` [Caml-list] Why List.map does not be implemented tail-recursively? Stephen Dolan
2015-06-01 12:02 ` Jon Harrop
2015-06-02 12:04 ` Stephen Dolan
2015-06-05 10:21 ` Goswin von Brederlow
2014-09-30 6:29 ` Goswin von Brederlow
-- strict thread matches above, loose matches on Subject: below --
2014-09-28 19:28 Shuai Wang
2014-09-28 19:45 ` Malcolm Matalka
2014-09-28 20:26 ` Yaron Minsky
2014-09-29 2:31 ` Shuai Wang
2014-09-29 4:09 ` Anthony Tavener
2014-09-29 5:40 ` Martin Jambon
2014-09-29 9:13 ` Erkki Seppala
2014-09-29 9:15 ` Erkki Seppala
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