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From: "Mattias Engdegård" <mattias@virtutech.se>
To: p.donadeo@gmail.com
Cc: caml-list@yquem.inria.fr
Subject: Re: [Caml-list] Strange behaviour of string_of_float
Date: Mon, 23 Jun 2008 10:32:54 +0200 (CEST)	[thread overview]
Message-ID: <20080623083254.7901F82040@kicki.hq.vtech> (raw)
In-Reply-To: <4b5157c30806221345p9be5daeqc65b3f6cfb3219b3@mail.gmail.com> (p.donadeo@gmail.com)

>My intent is to extract an ASCII representation of an OCaml float
>value so that it can be used to recreate *exactly* the same value, at
>least on the same architecture.

A somewhat more portable (and readable, maybe) representation of
floating-point numbers is in hex (a la C99). It is independent of the
precision and binary format used. Unfortunately, ocaml's Printf has
already appropriated %a for a different purpose, but it remains a good
option for those willing to do some manual work.

I have used it in the past to good effect in text-based interchange
formats between applications written in C.

Of course the decimal notation can unambiguously represent any
(binary) floating-point number, so that representation is fine if you
have confidence in the output and reading routines. See, for instance,
William Clinger's _How to Read Floating Point Numbers Accurately_
(http://ftp.ccs.neu.edu/pub/people/will/retrospective.pdf).
But decimal handling will always be a little slower.


  parent reply	other threads:[~2008-06-23  8:32 UTC|newest]

Thread overview: 15+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2008-06-22 16:56 Paolo Donadeo
2008-06-22 19:58 ` [Caml-list] " Richard Jones
2008-06-22 20:45   ` Paolo Donadeo
2008-06-23  1:25     ` Brian Hurt
2008-06-23  7:50       ` Paolo Donadeo
2008-06-23  8:32     ` Mattias Engdegård [this message]
2008-06-23  8:50       ` Olivier Andrieu
2008-06-23  8:35   ` Jon Harrop
2008-06-22 20:32 ` Daniel Bünzli
2008-06-22 20:50   ` Paolo Donadeo
2008-06-23  8:45     ` David Allsopp
2008-06-23  8:55       ` Olivier Andrieu
2008-06-23 12:06         ` David Allsopp
2008-06-23  1:06   ` Brian Hurt
2008-06-23  7:58     ` Xavier Leroy

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