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From: Jon Harrop <jon@ffconsultancy.com>
Organization: Flying Frog Consultancy Ltd.
To: caml-list@yquem.inria.fr
Subject: Re: [Caml-list] Strings
Date: Sat, 4 Apr 2009 18:26:00 +0100
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X-Spam: no; 0.00; bunzli:01 val:01 mutable:01 const:01 2009:98 frog:98 char:01 wrote:01 wrote:01 unix:01 unix:01 caml-list:01 strings:01 strings:01 data:02 

On Saturday 04 April 2009 18:11:20 Kuba Ober wrote:
> On Apr 3, 2009, at 1:50 PM, Daniel B=FCnzli wrote:
> > In fact I find the result of the following sequence of operations
> > very disappointing for a functional programming language :
> >
> >        Objective Caml version 3.11.0
> >
> > # Sys.os_type;;
> > - : string =3D "Unix"
> > # let s =3D Sys.os_type;;
> > val s : string =3D "Unix"
> > # s.[0] <- 'a';;
> > - : unit =3D ()
> > # Sys.os_type;;
> > - : string =3D "anix"
>
> Perhaps mutable data of any type should be markable as const, with the
> marking being permanent.

Would a phantom type parameter be sufficient:

  [`RO|`RW] string

> That's where I like C++/Qt copy-on-write strings a lot. They make life
> easy.

Just as long as they don't copy the entire string when I mutate a single ch=
ar!

=2D-=20
Dr Jon Harrop, Flying Frog Consultancy Ltd.
http://www.ffconsultancy.com/?e