From: Christophe TROESTLER <Christophe.Troestler+ocaml@umons.ac.be>
To: bhurt@spnz.org, jon@ffconsultancy.com, caml-list@yquem.inria.fr
Subject: Re: [Caml-list] stl?
Date: Wed, 04 Mar 2009 15:08:41 +0100 (CET) [thread overview]
Message-ID: <20090304.150841.990102838962322450.Christophe.Troestler+ocaml@umons.ac.be> (raw)
In-Reply-To: <alpine.DEB.2.00.0903032359570.7859@beast>
On Wed, 4 Mar 2009 01:11:18 -0500, Brian Hurt wrote:
>
> Try this. Let's reimplement Haskell's Fractional class, in Ocaml, and
> then do Newton's method using this new Fractional class. [...]
>
> module type Fractional = sig
> type t
> val ( +. ) : t -> t -> t
> val ( -. ) : t -> t -> t
> val ( *. ) : t -> t -> t
> val ( /. ) : t -> t -> t
> val fabs : t -> t
> (* other functions elided from brevity *)
> end;;
Small point: you forgot the comparison functions — they are necessary
for Ratio.
> [...] once you realize that the definitions of Fractional,
> FloatFractional, and RatioFractional all should be in the standard
> library (and the latter two should be just called Float and Ratio).
Well, they sort of are in the standard library already thanks to
Delimited Overloading! http://pa-do.forge.ocamlcore.org/
With it, your code can simply be written as a macro:
DEFINE NEWTON(M) = M.(
let rec newton epsilon f df x =
let x' = x - f x / df x in
if abs(x - x') < epsilon then x'
else newton epsilon f df x' in
newton)
let float_newton = NEWTON(Float)
let ratio_newton = NEWTON(Ratio)
(and with no performance lost at all for those concerned with clock
cycles).
I have released a new version of Delimited Overloading with that new
example (ad-hoc-newton.ml).
Enjoy,
ChriS
next prev parent reply other threads:[~2009-03-04 14:08 UTC|newest]
Thread overview: 72+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-03-03 21:40 stl? Raoul Duke
2009-03-03 22:31 ` [Caml-list] stl? Yoann Padioleau
2009-03-03 22:42 ` Till Varoquaux
2009-03-03 23:36 ` Jon Harrop
2009-03-04 0:13 ` Peng Zang
2009-03-04 0:58 ` Yoann Padioleau
2009-03-04 1:10 ` Raoul Duke
2009-03-04 1:19 ` Pal-Kristian Engstad
2009-03-04 1:21 ` Yoann Padioleau
2009-03-04 1:29 ` Jon Harrop
2009-03-04 14:26 ` Kuba Ober
2009-03-04 14:24 ` Kuba Ober
2009-03-03 23:42 ` Jon Harrop
2009-03-04 0:11 ` Brian Hurt
2009-03-04 1:05 ` Yoann Padioleau
2009-03-04 4:56 ` Brian Hurt
2009-03-04 20:11 ` Yoann Padioleau
2009-03-04 21:59 ` Brian Hurt
2009-03-04 22:42 ` Yoann Padioleau
2009-03-04 23:19 ` Jon Harrop
2009-03-04 23:03 ` Jon Harrop
2009-03-11 3:16 ` Brian Hurt
2009-03-11 5:57 ` David Rajchenbach-Teller
2009-03-11 6:11 ` David Rajchenbach-Teller
2009-03-04 1:59 ` Jon Harrop
2009-03-04 6:11 ` Brian Hurt
2009-03-04 14:08 ` Christophe TROESTLER [this message]
2009-03-04 14:19 ` Peng Zang
2009-03-04 16:14 ` Brian Hurt
2009-03-04 16:35 ` Andreas Rossberg
2009-03-04 16:40 ` Peng Zang
2009-03-04 21:43 ` Nicolas Pouillard
2009-03-05 11:24 ` Wolfgang Lux
2009-03-04 19:45 ` Jon Harrop
2009-03-04 21:23 ` Brian Hurt
2009-03-04 23:17 ` Jon Harrop
2009-03-05 2:26 ` stl? Stefan Monnier
2009-03-04 3:10 ` [Caml-list] stl? Martin Jambon
2009-03-04 6:18 ` Brian Hurt
2009-03-04 16:35 ` Mikkel Fahnøe Jørgensen
2009-03-04 16:48 ` Yoann Padioleau
2009-03-04 20:07 ` Jon Harrop
2009-03-04 20:31 ` Richard Jones
2009-03-04 20:49 ` Yoann Padioleau
2009-03-04 21:20 ` Andreas Rossberg
2009-03-04 21:51 ` Pal-Kristian Engstad
2009-03-04 22:50 ` Jon Harrop
2009-03-04 23:18 ` Pal-Kristian Engstad
2009-03-05 1:31 ` Jon Harrop
2009-03-05 2:15 ` Pal-Kristian Engstad
2009-03-05 3:26 ` Jon Harrop
2009-03-05 6:22 ` yoann padioleau
2009-03-05 7:02 ` Raoul Duke
2009-03-05 8:07 ` Erick Tryzelaar
2009-03-05 9:06 ` Richard Jones
2009-03-05 9:34 ` malc
2009-03-05 9:56 ` Richard Jones
2009-03-05 10:49 ` malc
2009-03-05 11:16 ` Richard Jones
2009-03-05 12:39 ` malc
2009-03-05 19:39 ` Jon Harrop
2009-03-05 21:10 ` Pal-Kristian Engstad
2009-03-05 22:41 ` Richard Jones
2009-03-05 22:53 ` malc
2009-03-05 8:59 ` Richard Jones
2009-03-05 17:50 ` Raoul Duke
2009-03-05 8:17 ` Kuba Ober
2009-03-05 1:06 ` Jon Harrop
2009-03-05 9:09 ` Richard Jones
2009-03-05 20:44 ` Jon Harrop
2009-03-05 20:50 ` Jake Donham
2009-03-05 21:28 ` [Caml-list] OCaml's intermediate representations Jon Harrop
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20090304.150841.990102838962322450.Christophe.Troestler+ocaml@umons.ac.be \
--to=christophe.troestler+ocaml@umons.ac.be \
--cc=bhurt@spnz.org \
--cc=caml-list@yquem.inria.fr \
--cc=jon@ffconsultancy.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).