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From: Jon Harrop <jon@jdh30.plus.com>
Organization: University of Cambridge
To: caml-list@yquem.inria.fr
Subject: Re: [Caml-list] String to list to string
Date: Thu, 10 Feb 2005 03:41:46 +0000
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On Thursday 10 February 2005 02:10, Juancarlo A=F1ez wrote:
> Why aren't there functions in the standard library to convert strings to
> lists of characters and back?

Outrageously, the core library fails to provide an arbitrary number of=20
arbitrary functions. This exact question came up recently. The answer was=20
essentially: Why string -> char list and not string -> char array? Why stri=
ng=20
=2D> char list and not string -> string list? And so on.

If you want succinct implementations then I'd go for:

let char_list_of_string s =3D
  let l =3D ref [] in
  String.iter (fun c -> l :=3D c :: !l) s;
  List.rev !l

let string_of_char_list l =3D
  String.concat "" (List.map (String.make 1) l)

> Haskell treats strings as lists of chars by default.

I see an optimisation...

=2D-=20
Dr Jon D Harrop, Flying Frog Consultancy Ltd.