From: Jon Harrop <jon@ffconsultancy.com>
To: caml-list@yquem.inria.fr
Subject: Re: [Caml-list] Variants & structural ordering
Date: Tue, 5 Feb 2008 15:04:38 +0000 [thread overview]
Message-ID: <200802051504.38263.jon@ffconsultancy.com> (raw)
In-Reply-To: <20080205081845.2D24D1C02531@mwinf2341.orange.fr>
On Tuesday 05 February 2008 08:21:21 Damien Guichard wrote:
> Hi everybody,
>
> Typically, when you declare:
>
> type card =
>
> | Card of int
> | Jack
> | Queen
> | King
> | Ace
>
> ;;
>
> The relation you wish is:
>
> Card(2) < ...< Card(10) < Jack < Queen < King < Ace
>
> And that's what you get when using F#.
Comparison is OCaml's achilles heel and this is one (minor) manifestation of
that. The ability to develop a program and break a use of polymorphic
comparison buried within it without knowing is far more serious and has
caused many people untold grief in the past.
SML's equality types are a slight improvement but F# and Haskell's solutions
are the best way forward AFAICT. OCaml will never be fixed in this sense but,
hopefully, a next-generation FPL implementation will solve these problems
without sacrificing OCaml's other benefits.
--
Dr Jon D Harrop, Flying Frog Consultancy Ltd.
http://www.ffconsultancy.com/products/?e
next prev parent reply other threads:[~2008-02-05 15:09 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2008-02-05 8:21 Damien Guichard
2008-02-05 9:47 ` [Caml-list] " Berke Durak
2008-02-05 9:48 ` Oliver Bandel
2008-02-05 15:04 ` Jon Harrop [this message]
2008-02-06 8:21 ` Michaël Grünewald
2008-02-07 15:50 ` Damien Doligez
2008-02-05 16:59 Damien Guichard
2008-02-05 17:25 ` Stéphane Lescuyer
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