Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Posting-Version: version B 2.10.2 9/18/84; site ucla-cs.ARPA Path: utzoo!watmath!clyde!burl!ulysses!allegra!mit-eddie!genrad!teddy!panda!talcott!harvard!seismo!hao!hplabs!sdcrdcf!trwrb!trwrba!cepu!ucla-cs!dimare From: dimare@ucla-cs.UUCP Newsgroups: net.lang,net.lang.pascal Subject: Comparing pointers in Pascal Message-ID: <3161@ucla-cs.ARPA> Date: Fri, 11-Jan-85 02:42:05 EST Article-I.D.: ucla-cs.3161 Posted: Fri Jan 11 02:42:05 1985 Date-Received: Sun, 13-Jan-85 09:02:11 EST Organization: UCLA Computer Science Department Lines: 30 Xref: watmath net.lang:1237 net.lang.pascal:183 I just ran into a problem with pointers in Pascal: I have two lists of pointers, and I need to find the intersection of them. Due to the nature of the problem, it's cheaper to keep these lists ordered. However, Pascal complains when I try to campare two pointer variables with operators different than = and <>: > Script started on Thu Jan 10 23:30:45 1985 > Warning: no access to tty; thus no job control in this shell... > e[2:1] c p.p; pi p.p > program blah (input, output); > var > x,y: ^integer; > begin > new(x); > if xend. > Thu Jan 10 23:27 1985 p.p: > E 6 - < not allowed on pointers - only allow = and <> > e[2:2] > script done on Thu Jan 10 23:31:03 1985 I'm not trying to do arithmetic with pointers, I only need to order them. I think this restriction is excessive. Is there a good reason for it? Would Modula-2 behave in the same way? Is it that Berkely Pascal is a wacko? Adolfo ///