From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <pierre.weis@inria.fr>
Received: from concorde.inria.fr (concorde.inria.fr [192.93.2.39])
	by yquem.inria.fr (Postfix) with ESMTP id E7408BC8A
	for <caml-list@yquem.inria.fr>; Sun, 30 Jan 2005 10:51:15 +0100 (CET)
Received: from pauillac.inria.fr (pauillac.inria.fr [128.93.11.35])
	by concorde.inria.fr (8.13.0/8.13.0) with ESMTP id j0U9pFoV018740
	for <caml-list@yquem.inria.fr>; Sun, 30 Jan 2005 10:51:15 +0100
Received: from concorde.inria.fr (concorde.inria.fr [192.93.2.39]) by pauillac.inria.fr (8.7.6/8.7.3) with ESMTP id KAA13374 for <caml-list@pauillac.inria.fr>; Sun, 30 Jan 2005 10:51:15 +0100 (MET)
Received: from smtp1.wanadoo.fr (smtp1.wanadoo.fr [193.252.22.30])
	by concorde.inria.fr (8.13.0/8.13.0) with ESMTP id j0U9pERu018735
	for <caml-list@inria.fr>; Sun, 30 Jan 2005 10:51:15 +0100
Received: from me-wanadoo.net (localhost [127.0.0.1])
	by mwinf0107.wanadoo.fr (SMTP Server) with ESMTP id D73C9A00018A
	for <caml-list@inria.fr>; Sun, 30 Jan 2005 10:51:14 +0100 (CET)
Received: from nono (ARouen-106-1-9-53.w80-14.abo.wanadoo.fr [80.14.114.53])
	by mwinf0107.wanadoo.fr (SMTP Server) with SMTP id 8D96DA000188
	for <caml-list@inria.fr>; Sun, 30 Jan 2005 10:51:14 +0100 (CET)
X-ME-UUID: 20050130095114580.8D96DA000188@mwinf0107.wanadoo.fr
Message-ID: <001901c506b1$7d89fb60$0100a8c0@mshome.net>
From: =?iso-8859-1?Q?Fr=E9d=E9ric_Gava?= <frederic.gava@wanadoo.fr>
To: <caml-list@inria.fr>
Subject: Fw: [Caml-list] Missing a function
Date: Sun, 30 Jan 2005 10:53:02 +0100
MIME-Version: 1.0
Content-Type: text/plain;
	charset="iso-8859-1"
Content-Transfer-Encoding: 8bit
X-Priority: 3
X-MSMail-Priority: Normal
X-Mailer: Microsoft Outlook Express 5.50.4133.2400
X-MimeOLE: Produced By Microsoft MimeOLE V5.50.4133.2400
X-Miltered: at concorde with ID 41FCAE13.000 by Joe's j-chkmail (http://j-chkmail.ensmp.fr)!
X-Miltered: at concorde with ID 41FCAE12.001 by Joe's j-chkmail (http://j-chkmail.ensmp.fr)!
X-Spam: no; 0.00; gava:01 gava:01 caml-list:01 stdlib:01 functor:01 functor:01 ord:01 struct:01 ord:01 sig:01 val:01 expansive:01 ....:98 ...:98 int:01 
X-Spam-Checker-Version: SpamAssassin 3.0.0 (2004-09-13) on yquem.inria.fr
X-Spam-Status: No, score=0.0 required=5.0 tests=none autolearn=disabled 
	version=3.0.0
X-Spam-Level: 

Hi,
>
> > Another option is to build on top of the stdlib Map functor another
> > functor that keeps track of the cardinal of a map :
> >
> > module CMap = functor (Ord : Map.OrderedType) ->
> >   (struct
> >     module M = Map.Make (Ord)
> >
> >     type key = M.key
> >     type 'a t = int * 'a M.t
> >
> >     let cardinal = fst
> >
> >     let empty = 0, M.empty
> >
> >     let add k v (n, m) = (n + 1, M.add k v m)
> >
> >     let find k (_, m) = M.find k m
> >
> > ....
> >    : sig
> >        include Map.S
> >        val cardinal : 'a t -> int
> >      end)
> >
Hum. To remove an element, you have to test is its exists or not before
decrease n. It could be to much cost expansive...no ?

Regards,
Frédéric Gava