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From: Jeremy Yallop <jeremy.yallop@ed.ac.uk>
To: Fabrice Marchant <fabricemarchant@free.fr>
Cc: caml-list@yquem.inria.fr
Subject: Re: [Caml-list] functions' recursive construction
Date: Mon, 07 Jul 2008 21:40:36 +0100	[thread overview]
Message-ID: <48727F44.8010500@ed.ac.uk> (raw)
In-Reply-To: <20080707202839.272a4b0b@free.fr>

Fabrice Marchant wrote:
> After Coq, maybe could we program this in Lisp ?

Yes, although this is rather off-topic.  Here are two solutions in 
(rather rusty) Scheme, both zero-based again.  A curried version:

   (define (f n)
     (cond
      ((zero? n) (lambda (x) x))
      (#t        (lambda (_) (f (- n 1))))))

Now

   > ((f 0) 1)
   1
   > (((((f 3) 1) 2) 3) 4)
   4

An uncurried version:

   (define (f n)
     (lambda args (list-ref args n)))

Now

   > ((f 0) 1)
   1
   > ((f 3) 1 2 3 4)
   4

Jeremy.


  reply	other threads:[~2008-07-07 20:40 UTC|newest]

Thread overview: 14+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2007-05-22 23:17 Damien Lefortier
2007-05-22 23:21 ` [Caml-list] " Jon Harrop
2007-05-22 23:31   ` Lukasz Stafiniak
2007-05-22 23:32     ` Lukasz Stafiniak
2007-05-22 23:41       ` Jon Harrop
2007-05-23  6:25     ` Jean-Christophe Filliatre
2008-07-07 18:01 ` Fabrice Marchant
     [not found]   ` <a58674cc0807071304x1640d670sde3045a0920a5922@mail.gmail.com>
2008-07-07 18:28     ` Fabrice Marchant
2008-07-07 20:40       ` Jeremy Yallop [this message]
     [not found]   ` <C3DD7276-23D5-41BE-A272-7579586A5559@gmail.com>
2008-07-07 18:36     ` Fabrice Marchant
2008-07-07 20:25   ` Jeremy Yallop
2008-07-07 19:11     ` Fabrice Marchant
2008-07-07 22:48       ` asmadeus77
2008-07-08  9:24       ` Daniel Bünzli

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