From mboxrd@z Thu Jan 1 00:00:00 1970 Received: (from weis@localhost) by pauillac.inria.fr (8.7.6/8.7.3) id TAA14599 for caml-red; Thu, 14 Dec 2000 19:24:42 +0100 (MET) Received: from nez-perce.inria.fr (nez-perce.inria.fr [192.93.2.78]) by pauillac.inria.fr (8.7.6/8.7.3) with ESMTP id OAA20656 for ; Wed, 13 Dec 2000 14:41:04 +0100 (MET) Received: from mrwall.kal.com (mrwall.kal.com [194.193.14.236]) by nez-perce.inria.fr (8.11.1/8.10.0) with SMTP id eBDDf3L03481 for ; Wed, 13 Dec 2000 14:41:04 +0100 (MET) Received: from mrwall.kal.com [194.193.14.236] (HELO localhost) by mrwall.kal.com (AltaVista Mail V2.0J/2.0J BL25J listener) id 0000_0045_3a37_7cb0_5a7c; Wed, 13 Dec 2000 13:42:08 +0000 Received: from somewhere by smtpxd Message-ID: <3145774E67D8D111BE6E00C0DF418B6638D1D3@nt.kal.com> From: Dave Berry To: Chet Murthy , STARYNKEVITCH Basile Cc: caml-list@inria.fr Subject: RE: callcc/cps-style programming Date: Wed, 13 Dec 2000 13:44:20 -0000 MIME-Version: 1.0 X-Mailer: Internet Mail Service (5.0.1460.8) Content-Type: text/plain; charset="iso-8859-1" Sender: weis@pauillac.inria.fr Chet, I agree with you about the (lack of) utility of call/cc. (Although my agreement might stem from my complete inability to understand any program that uses it. It really is the functional equivalent of the goto -- in several ways). What caught my attention in your message was your comments about threads. Several people have found lightweight threads to be useful in GUI libraries, and in writing server programs (although for the latter application, OS threads offer advantages on multi-processors). Erlang has found success, and Erlang programs use a huge number of lightweight threads/processes. I would like to know more about the Ousterhout paper on events vs. threads. Does this paper put Erlang on the "events" side of the distinction, or the "threads" side? I.e. does "events" refer to separate processes communicating by sending values down channels, or to the sort of event loops found in many GUI libraries (and which are central to Windows and OS/2)? Please could you post the full citation (or even a URL) for the paper? Thanks, Dave. -----Original Message----- From: Chet Murthy [mailto:chet@watson.ibm.com] Sent: Saturday, December 09, 2000 18:49 To: STARYNKEVITCH Basile Cc: Joe Lisp; caml-list@inria.fr Subject: Re: callcc/cps-style programming As for lightweight threading, well, it's nice that you can implement them with continuations, but the real purpose of threading is to interface with some external source of events. Every such source (except for the lowest-level X windows protocol) requires operating system-level thread-contexts, so you'll end up needing heavyweight threads anyway. Finally, well, as Ousterhout noted in his seminal paper on events vs. threads, there are rarely any good reasons to use threads, if you have sufficient abstraction power (closures!) in your language.