From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!not-for-mail From: Emanuel Berg Newsgroups: gmane.emacs.help Subject: Re: Emacs history, and "Is Emacs difficult to learn?" Date: Thu, 01 Aug 2013 22:48:42 +0200 Organization: Aioe.org NNTP Server Message-ID: <87fvut16j9.fsf@VLAN-3434.student.uu.se> References: <87y58pplcp.fsf@VLAN-3434.student.uu.se> <87fvuwgsv0.fsf@VLAN-3434.student.uu.se> <075751cf-97a3-4d01-8fb1-4ffbc0180f3f@googlegroups.com> <878v0oxfdw.fsf@VLAN-3434.student.uu.se> <87a9l4rs76.fsf@VLAN-3434.student.uu.se> <39e6407d-c4fd-4dc1-b47f-a1ba4119c7cb@googlegroups.com> <87iozqzjjq.fsf@VLAN-3434.student.uu.se> <871u6dpjar.fsf@VLAN-3434.student.uu.se> <14bebcfe-2311-4bb3-8154-4cc803962c71@googlegroups.com> <6be5c9a9-ba78-4169-8020-aa9e4c30a759@googlegroups.com> NNTP-Posting-Host: plane.gmane.org Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii X-Trace: ger.gmane.org 1375390221 22999 80.91.229.3 (1 Aug 2013 20:50:21 GMT) X-Complaints-To: usenet@ger.gmane.org NNTP-Posting-Date: Thu, 1 Aug 2013 20:50:21 +0000 (UTC) To: help-gnu-emacs@gnu.org Original-X-From: help-gnu-emacs-bounces+geh-help-gnu-emacs=m.gmane.org@gnu.org Thu Aug 01 22:50:23 2013 Return-path: Envelope-to: geh-help-gnu-emacs@m.gmane.org Original-Received: from lists.gnu.org ([208.118.235.17]) by plane.gmane.org with esmtp (Exim 4.69) (envelope-from ) id 1V4zpG-0007zi-7s for geh-help-gnu-emacs@m.gmane.org; Thu, 01 Aug 2013 22:50:22 +0200 Original-Received: from localhost ([::1]:53898 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1V4zpF-0000cd-SL for geh-help-gnu-emacs@m.gmane.org; Thu, 01 Aug 2013 16:50:21 -0400 Original-Path: usenet.stanford.edu!news.kjsl.com!feeder.erje.net!eu.feeder.erje.net!newsfeed.datemas.de!rt.uk.eu.org!aioe.org!.POSTED!not-for-mail Original-Newsgroups: gnu.emacs.help Original-Lines: 42 Original-NNTP-Posting-Host: SWN/nubmpQxYKwY7hPy4YA.user.speranza.aioe.org Original-X-Complaints-To: abuse@aioe.org User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/23.4 (gnu/linux) X-Notice: Filtered by postfilter v. 0.8.2 Cancel-Lock: sha1:fedK2UYq7aLc0hbt4fiSJ4oAwko= Original-Xref: usenet.stanford.edu gnu.emacs.help:200376 X-BeenThere: help-gnu-emacs@gnu.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: Users list for the GNU Emacs text editor List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: help-gnu-emacs-bounces+geh-help-gnu-emacs=m.gmane.org@gnu.org Original-Sender: help-gnu-emacs-bounces+geh-help-gnu-emacs=m.gmane.org@gnu.org Xref: news.gmane.org gmane.emacs.help:92642 Archived-At: Stefan Monnier writes: > But yes, jumping in the middle of an instruction can be useful, > if the "tail" of the byte-sequence encoding that instruction > "happens" to be a valid instruction. E.g. back in the 68000, to > skip a 4B instruction you could either use a jump, or (more > efficient) place that 4B instruction in the "immediate constant" > part of a CMP (compare) instruction whose result you just don't > use (i.e. this CMP instruction was just used as a 6B no-op whose > last 4B was free for you to choose as you please). So, jump = compare(... jump ...), in that case? Interesting. For sure, that is *far* from FP! What would you gain with the compare method, um, "compared" to just jumping? By the way, I think *this* (and the C pointers) is the monk stuff. And a bit of the point with C is that you have memory addressing, the binary arithmetic, etc., *if* you need it. You can get as close as you wish. Not the least for programming for a specific, peculiar platform... (embedded systems, etc.) Yes, Lisp (and FP in general) is much more gentle. But let's not get carried away: if a decent programmer (to begin with) does C for say, one year, just because it is not FP does not mean the code is without discipline, not modular, etc. And there are no overflows due to pointers! That guy will be a very self-confident juggler. > self-modify the code ? > Or to use some of the instruction bytes as data-constants (in > case they happen to contain the same bit-pattern). This is what I said (almost)! I guess there were no assigned bitstring to append as a prefix to "quote" such constants? (Not enough room?) -- Emanuel Berg - programmer (hire me! CV below) computer projects: http://user.it.uu.se/~embe8573 internet activity: http://home.student.uu.se/embe8573