From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Delivered-To: caml-list@yquem.inria.fr Received: from concorde.inria.fr (concorde.inria.fr [192.93.2.39]) by yquem.inria.fr (Postfix) with ESMTP id BBF27BC75 for ; Mon, 14 Feb 2005 18:23:19 +0100 (CET) Received: from mail.dcs.qmul.ac.uk (vicar.dcs.qmul.ac.uk [138.37.95.146]) by concorde.inria.fr (8.13.0/8.13.0) with ESMTP id j1EHNJv2026913 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO) for ; Mon, 14 Feb 2005 18:23:19 +0100 Received: from xenografia.plus.com ([212.159.85.26] helo=[192.168.7.2]) by mail.dcs.qmul.ac.uk with esmtpsa (TLSv1:DHE-RSA-AES256-SHA:256) (Exim 4.44) id 1D0jwM-0004oA-2i; Mon, 14 Feb 2005 17:23:18 +0000 Message-ID: <4210DFE1.5030208@dcs.qmul.ac.uk> Date: Mon, 14 Feb 2005 17:29:05 +0000 From: Martin Berger User-Agent: Mozilla Thunderbird 1.0 (X11/20041207) X-Accept-Language: en-us, en MIME-Version: 1.0 To: Thomas Fischbacher Cc: caml-list@yquem.inria.fr Subject: Re: [Caml-list] The boon of static type checking References: <877e9a17050206221653d14456@mail.gmail.com> <200502131451.02231.edgin@slingshot.co.nz> <20050213112630.73930e19@hobbes> <877e9a1705021312525337a907@mail.gmail.com> <877e9a1705021314512ff095b9@mail.gmail.com> <877e9a1705021316114d4e10f0@mail.gmail.com> In-Reply-To: Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit X-DCS-Interface-Port: 465 X-DCS-Auth-User: martinb X-DCS-clamav-result: clean (1D0jwM-0004oA-2i) X-DCS-uvscan-result: clean (1D0jwM-0004oA-2i) X-Miltered: at concorde with ID 4210DE87.001 by Joe's j-chkmail (http://j-chkmail.ensmp.fr)! X-Spam: no; 0.00; dcs:01 qmul:01 caml-list:01 branching:01 abstractions:01 high-level:01 semantics:01 convincing:01 ml-like:01 logics:01 lambda:01 computation:01 interaction:01 passing:01 checking:01 X-Spam-Checker-Version: SpamAssassin 3.0.2 (2004-11-16) on yquem.inria.fr X-Spam-Status: No, score=0.0 required=5.0 tests=none autolearn=disabled version=3.0.2 X-Spam-Level: > That's how it's supposed to be. Especially scheme tries to be nothing else > but just the minimal "functional assembly language". So one can put other > languages on top of it. the words "functional" and "minimal" may be considered contradictory as the basic primitive of functional programming, beta reduction, is a very heavy operation that can successfully be decomposed into more lightweight operations like: - state change + conditional branching. - continuation passing - name-passing interaction. (of those the third is the most elementary and general and encompasses the others). putting any of those on top of beta-reduction generally leads to something ugly. functional abstractions are extremely useful in many computational situations, but they are high-level, not something one can use successfully as a foundation to start from. several decades of failed attempts at founding (the semantics of) computation on lambda calculus shows this. the difficulties of finding convincing hoare-logics for ML-like languages, a problem that has really only been solved this year, and on the basis of pi-calculus, is another indication in this direction. as an aside, are there any good program logics for languages with macro-facilities like lisp-dialects? martin