Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Path: utzoo!watmath!clyde!burl!hou3c!hocda!houxm!vax135!cornell!uw-beaver!tektronix!hplabs!sri-unix!O'KeefeHPS From: O'KeefeHPS@sri-unix.UUCP Newsgroups: net.lang.prolog Subject: A Hack for DEC-10 Prolog Input Message-ID: <12130@sri-arpa.UUCP> Date: Mon, 17-Sep-84 08:01:48 EDT Article-I.D.: sri-arpa.12130 Posted: Mon Sep 17 08:01:48 1984 Date-Received: Tue, 25-Sep-84 20:39:45 EDT Lines: 41 From: O'Keefe HPS (on ERCC DEC-10) I've often moaned about the "fact" that DEC-10 Prolog doesn't let you have more than one channel reading from the same file. While I had realised that in C-Prolog I could say see('fred') for channel A see('./fred') for channel B see('../fred') for channel C and so on (just stick N "./"s after the last "/"), I didn't realise that something similar could be done in DEC-10 Prolog. But it can! Use see('fred') for channel A see('Fred') for channel B see('FRED') for channel C and so on. The Bottoms-10 operating system ignores case, but DEC-10 Prolog doesn't! Myself, I class this as a hack, but if you have a program which has to keep its channels intact despite the user opening and closing things at least you can use all upper case yourself and force the user's file names to lower case. I discovered this while working on the input/output section of my "draft standard for Prolog built in predicates". I've come up with a new set of basic operations which should be generally implementable and which have some nice properties, and to excuse this decided to write a backwards compatibility library. While testing this, I tried out a number of strange things, such as tell(a+b). (It just fails.) I'm prepared to defend almost any aspect of DEC-10 Prolog at length, but not the file handling commands. ***Sender closed connection*** === Network Mail from host su-score.arpa on Tue Sep 18 02:44:24 ===