Path: csiph.com!v102.xanadu-bbs.net!xanadu-bbs.net!feeder.erje.net!eu.feeder.erje.net!weretis.net!feeder1.news.weretis.net!news.szaf.org!news.gnuher.de!rz.uni-karlsruhe.de!feed.news.schlund.de!schlund.de!news.online.de!not-for-mail From: Bernd Paysan Newsgroups: comp.lang.forth Subject: Re: DOES> and flash Date: Sat, 18 Jan 2014 20:24:08 +0100 Organization: 1&1 Internet AG Lines: 26 Message-ID: References: <7xvby8f6md.fsf@ruckus.brouhaha.com> <2014Jan15.185210@mips.complang.tuwien.ac.at> <52d703e1.1937804717@news.demon.co.uk> <2014Jan16.103021@mips.complang.tuwien.ac.at> <2d2fa398-1a61-4f21-8d1b-67180cae2536@googlegroups.com> <2014Jan17.174343@mips.complang.tuwien.ac.at> <2014Jan18.125639@mips.complang.tuwien.ac.at> <2014Jan18.183619@mips.complang.tuwien.ac.at> NNTP-Posting-Host: p5dcd7b9d.dip0.t-ipconnect.de Mime-Version: 1.0 Content-Type: text/plain; charset="ISO-8859-1" Content-Transfer-Encoding: 7Bit X-Trace: online.de 1390073048 15384 93.205.123.157 (18 Jan 2014 19:24:08 GMT) X-Complaints-To: abuse@einsundeins.com NNTP-Posting-Date: Sat, 18 Jan 2014 19:24:08 +0000 (UTC) User-Agent: KNode/4.11.4 Xref: csiph.com comp.lang.forth:27940 Andrew Haley wrote: > Oh, I see. It depends on what form an XT takes; it doesn't have to be > a simple address. You can take it for granted that on a small embedded system it is a simple address. The traditional computer science tells you that every problem can be solved by another indirection, but at cost of speed and memory. And therefore, small embedded systems will not have these indirections. The BUILDS ( xt "name" -- ) proposal has another problem: A doer is not an xt, it is the content of an xt. With the two-cell code-field approach, this doesn't cause a problem: Your first cell, dobuilds, would simply take the second cell and execute it, after pushing the body on the stack, so : Value ['] @ builds , ; will work (with @ being a primitive). However, if the implementer likes to keep a one-cell code-field approach even for childs of builds, and use the doesjmp approach for implementing high-level doers, using an xt doesn't work. -- Bernd Paysan "If you want it done right, you have to do it yourself" http://bernd-paysan.de/