From mboxrd@z Thu Jan 1 00:00:00 1970 Path: main.gmane.org!not-for-mail From: David Kastrup Newsgroups: gmane.emacs.help Subject: Re: Reading portions of large files Date: 11 Jan 2003 11:42:12 +0100 Organization: T-Online Sender: help-gnu-emacs-bounces+gnu-help-gnu-emacs=m.gmane.org@gnu.org Message-ID: References: NNTP-Posting-Host: main.gmane.org Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii X-Trace: main.gmane.org 1042281928 7997 80.91.224.249 (11 Jan 2003 10:45:28 GMT) X-Complaints-To: usenet@main.gmane.org NNTP-Posting-Date: Sat, 11 Jan 2003 10:45:28 +0000 (UTC) Return-path: Original-Received: from monty-python.gnu.org ([199.232.76.173]) by main.gmane.org with esmtp (Exim 3.35 #1 (Debian)) id 18XJ8p-00024q-00 for ; Sat, 11 Jan 2003 11:45:27 +0100 Original-Received: from localhost ([127.0.0.1] helo=monty-python.gnu.org) by monty-python.gnu.org with esmtp (Exim 4.10.13) id 18XJ9A-0004ZI-03 for gnu-help-gnu-emacs@m.gmane.org; Sat, 11 Jan 2003 05:45:48 -0500 Original-Path: shelby.stanford.edu!newsfeed.stanford.edu!news-spur1.maxwell.syr.edu!news.maxwell.syr.edu!feed.news.nacamar.de!newsfeed01.sul.t-online.de!newsmm00.sul.t-online.com!t-online.de!news.t-online.com!not-for-mail Original-Newsgroups: gnu.emacs.help Original-Lines: 47 Original-X-Trace: news.t-online.com 1042281733 04 14628 8nqFEkkbXVAUl4 030111 10:42:13 Original-X-Complaints-To: abuse@t-online.com X-Sender: 520018396234-0001@t-dialin.net X-Face: 2FEFf>]>q>2iw=B6,xrUubRI>pR&Ml9=ao@P@i)L:\urd*t9M~y1^:+Y]'C0~{mAl`oQuAl \!3KEIp?*w`|bL5qr,H)LFO6Q=qx~iH4DN;i"; /yuIsqbLLCh/!U#X[S~(5eZ41to5f%E@'ELIi$t^ Vc\LWP@J5p^rst0+('>Er0=^1{]M9!p?&:\z]|;&=NP3AhB!B_bi^]Pfkw User-Agent: Gnus/5.09 (Gnus v5.9.0) Emacs/21.3.50 Original-Xref: shelby.stanford.edu gnu.emacs.help:108835 Original-To: help-gnu-emacs@gnu.org X-BeenThere: help-gnu-emacs@gnu.org X-Mailman-Version: 2.1b5 Precedence: list List-Id: Users list for the GNU Emacs text editor List-Help: List-Post: List-Subscribe: , List-Archive: List-Unsubscribe: , Errors-To: help-gnu-emacs-bounces+gnu-help-gnu-emacs=m.gmane.org@gnu.org Xref: main.gmane.org gmane.emacs.help:5364 X-Report-Spam: http://spam.gmane.org/gmane.emacs.help:5364 "Eli Zaretskii" writes: > > From: David Kastrup > > Newsgroups: gnu.emacs.help > > Date: 10 Jan 2003 21:51:49 +0100 > > > > BTW, would it be terribly complicated to extend the range of Lisp > > integers to 31bit? > > It's not terribly hard, but IIRC the current consensus among the Emacs > maintainers is that it's not important enough to do that because > before long all machines will have 64-bit compilers. > > Perhaps this should be discussed again on the developers' list. > > > Integers don't need any garbage collection or tag bits per se. > > They need to be distinguishable from other Lisp types, so their tag > bitfield cannot have an arbitrary bit pattern. Yes, but a single bit is sufficient for that distinction. This could even speed up operations, since the sign bit is a candidate that can be rather quickly checked. Something like if (x < 0) will establish that something is an integer, (x + 0x40000000) will yield the value of the integer, and (x | 0x8000000) will convert an integer back to a Lisp number. I don't know whether an integer Lisp object needs to be identical to an integer. If it does, then the above needs an offset of 0x40000000 everywhere, of course. > > Emacs has a most-positive-fixnum of 134217727, while XEmacs has > > 1073741823, more than 8 times as much. So it would appear to be > > possible in theory. > > IIRC, the XEmacs way requires extensive changes in how Emacs works, > but I don't remember the details. No clue about that. -- David Kastrup, Kriemhildstr. 15, 44793 Bochum