From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.1.3 (2006-06-01) on yquem.inria.fr X-Spam-Level: X-Spam-Status: No, score=0.0 required=5.0 tests=none autolearn=disabled version=3.1.3 X-Original-To: caml-list@yquem.inria.fr Delivered-To: caml-list@yquem.inria.fr Received: from mail3-relais-sop.national.inria.fr (mail3-relais-sop.national.inria.fr [192.134.164.104]) by yquem.inria.fr (Postfix) with ESMTP id A1C67BC69 for ; Wed, 3 Oct 2007 13:48:33 +0200 (CEST) X-IronPort-Anti-Spam-Filtered: true X-IronPort-Anti-Spam-Result: AgAAAIoeA0fAXQInemdsb2JhbACOOAEBCQo X-IronPort-AV: E=Sophos;i="4.21,224,1188770400"; d="scan'208";a="3695935" Received: from concorde.inria.fr ([192.93.2.39]) by mail3-smtp-sop.national.inria.fr with ESMTP; 03 Oct 2007 13:48:33 +0200 Received: from mail4-relais-sop.national.inria.fr (mail4-relais-sop.national.inria.fr [192.134.164.105]) by concorde.inria.fr (8.13.6/8.13.6) with ESMTP id l93BmUlJ017049 (version=TLSv1/SSLv3 cipher=RC4-SHA bits=128 verify=OK) for ; Wed, 3 Oct 2007 13:48:33 +0200 X-IronPort-AV: E=Sophos;i="4.21,224,1188770400"; d="scan'208";a="17235529" Received: from yquem.inria.fr ([128.93.8.37]) by mail4-relais-sop.national.inria.fr with ESMTP; 03 Oct 2007 13:48:32 +0200 Received: by yquem.inria.fr (Postfix, from userid 25991) id B508FBC69; Wed, 3 Oct 2007 13:48:32 +0200 (CEST) Date: Wed, 3 Oct 2007 13:48:32 +0200 From: Daniel de Rauglaudre To: caml-list@inria.fr Subject: Re: [Caml-list] Re: Locally-polymorphic exceptions [was: folding over a file] Message-ID: <20071003114832.GB23824@yquem.inria.fr> References: <20071003083529.40DA2A99F@Adric.metnet.fnmoc.navy.mil> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.9i X-Miltered: at concorde with ID 4703818E.000 by Joe's j-chkmail (http://j-chkmail . ensmp . fr)! X-Spam: no; 0.00; rauglaudre:01 rauglaudre:01 oleg:01 oleg:01 channel-:01 'a-:01 'b-:01 blabla:01 prev:01 val:01 val:01 prev:01 rec:01 exception:01 exception:01 Hi, > 2007/10/3, oleg@pobox.com : > > exception Done of 'a > > let fold_file (file: in_channel) > (read_func: in_channel->'a) > (elem_func: 'a->'b->'b) > (seed: 'b) = > [...] Personnally, I don't like exceptions because they generally control too much part of code. I often practice things like: match try Some (...) with [ Exception -> None ] with [ Some v -> blabla | None -> blublu ] I would write your function like this: value fold_file (file : in_channel) (read_func : in_channel -> 'a) (elem_func : 'a -> 'b -> 'b) (seed : 'b) = let rec loop prev_val = match try Some (read_func file) with [ End_of_file -> None ] with [ Some input -> let combined_val = elem_func input prev_val in loop combined_val | None -> prev_val ] in loop seed ; -- Daniel de Rauglaudre http://pauillac.inria.fr/~ddr/