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Subject: Re: [Caml-list] Strange performances
From: Benjamin Canou <benjamin.canou@gmail.com>
To: caml-list@yquem.inria.fr
Cc: Jon Harrop <jon@ffconsultancy.com>
In-Reply-To: <200801181743.22912.jon@ffconsultancy.com>
References: <1200619933.6383.47.camel@benjamin-laptop>
	 <20080118.181206.85503086.garrigue@math.nagoya-u.ac.jp>
	 <1200675314.6345.32.camel@benjamin-laptop>
	 <200801181743.22912.jon@ffconsultancy.com>
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Date: Fri, 18 Jan 2008 20:53:19 +0100
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X-Spam: no; 0.00; mutable:01 downto:01 imho:01 rec:01 caml-list:01 unsafe:01 imperative:01 benjamin:01 benjamin:01 data:02 structures:02 string:02 string:02 vendredi:03 naive:03 

Le vendredi 18 janvier 2008 à 17:43 +0000, Jon Harrop a écrit :
> As an aside, I would recommend using an imperative style with mutable data 
> structures like "string" are involved:
> 
>   let list_of_string string =
>     let list = ref [] in
>     for i = String.length string - 1 downto 0 do
>       list := string.[i] :: !list
>     done;
>     !list;;
> 

Actually, and as I said in my first message, it was a really naive
implementation, for which I used the more compact and quick to write
code.

Imho, I would not add references and write the function like this :

let list_of_string str =
  let rec aux i acc =
    if i < 0 then acc
    else aux (i - 1) (String.unsafe_get str i :: acc)
  in aux (String.length str - 1) []

But we are digressing...

  Benjamin.