From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Delivered-To: caml-list@yquem.inria.fr Received: from nez-perce.inria.fr (nez-perce.inria.fr [192.93.2.78]) by yquem.inria.fr (Postfix) with ESMTP id D2B06BC88 for ; Mon, 7 Feb 2005 18:24:44 +0100 (CET) Received: from will.iki.fi (will.iki.fi [217.169.64.20]) by nez-perce.inria.fr (8.13.0/8.13.0) with ESMTP id j17HOiaU013769 for ; Mon, 7 Feb 2005 18:24:44 +0100 Received: from ZMXLVII.dsl.saunalahti.fi (ZMXLVII.dsl.saunalahti.fi [85.76.70.148]) by will.iki.fi (Postfix) with ESMTP id 09C5468; Mon, 7 Feb 2005 19:24:44 +0200 (EET) Subject: Re: [Caml-list] The boon of static type checking From: Ville-Pertti Keinonen To: skaller@users.sourceforge.net Cc: Brian Hurt , Jon , caml-list@yquem.inria.fr In-Reply-To: <1107795520.13571.118.camel@pelican.wigram> References: <1107773824.654.43.camel@localhost> <1107795520.13571.118.camel@pelican.wigram> Content-Type: text/plain Date: Mon, 07 Feb 2005 19:24:42 +0200 Message-Id: <1107797082.655.14.camel@localhost> Mime-Version: 1.0 X-Mailer: Evolution 2.0.3 FreeBSD GNOME Team Port Content-Transfer-Encoding: 7bit X-Miltered: at nez-perce with ID 4207A45C.000 by Joe's j-chkmail (http://j-chkmail.ensmp.fr)! X-Spam: no; 0.00; caml-list:01 wrote:01 wrote:01 iirc:01 transformed:01 transformed:01 cps:01 cps:01 functions:01 imperative:01 checking:01 purely:02 compiling:02 functional:02 functional:02 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: On Tue, 2005-02-08 at 03:58 +1100, skaller wrote: > On Mon, 2005-02-07 at 21:57, Ville-Pertti Keinonen wrote: > > > > While the single-assignment aspect of SSA could be considered > > "functional", representing control flow using blocks and branches can't. > > Yeah it can, it has been proven SSA is equivalent to > a purely functional representation. Branches are done with CPS. > Sorry I can't find the paper: the paper was actually written > to explain *why* SSA is easy to analyse. It's kind of equivalent (IIRC SSA can be transformed to CPS, but (full) CPS can't be transformed trivially into SSA), but I still think SSA is not functional in style. Blocks are an imperative concept. SSA also does nothing to address the interesting parts of compiling functional languages - dealing with functions and calls.