From: Martin Jambon <martin.jambon@ens-lyon.org>
To: "Daniel Bünzli" <daniel.buenzli@erratique.ch>
Cc: caml-list@inria.fr
Subject: Re: [Caml-list] Unboxed float tuples
Date: Sun, 08 Nov 2009 18:29:17 +0100 [thread overview]
Message-ID: <4AF6FFED.2060900@ens-lyon.org> (raw)
In-Reply-To: <91a3da520911080801w6637b652w94a717a830b1c5bd@mail.gmail.com>
Daniel Bünzli wrote:
> Tuples and records are represented the same way. However when it comes
> to records with only floats fields we get a special unboxed
> representation.
>
> Why don't we get that for tuples of floats only ?
Because polymorphic functions like fst would break (or would require extra
runtime checking).
Note that ('a * 'b) is pretty much the same as:
type ('a, 'b) tuple = { a : 'a; b : 'b }
# Obj.tag (Obj.repr { a = 1.0; b = 1.0 });;
- : int = 0
# Obj.tag (Obj.repr (1.0, 1.0));;
- : int = 0
whereas:
# Obj.tag (Obj.repr { Complex.re = 1.0; im = 1.0 });;
- : int = 254
Martin
--
http://mjambon.com/
next prev parent reply other threads:[~2009-11-08 17:29 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-11-08 16:01 Daniel Bünzli
2009-11-08 16:46 ` [Caml-list] " Jon Harrop
2009-11-08 17:29 ` Martin Jambon [this message]
2009-11-08 19:39 ` Brian Hurt
2009-11-08 20:36 ` Jon Harrop
2009-11-08 20:09 ` Richard Jones
2009-11-08 20:58 ` Christophe Raffalli
2009-11-08 21:25 ` Lukasz Stafiniak
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