Path: utzoo!mnetor!uunet!husc6!ut-sally!utah-cs!defun.utah.edu!shebs
From: shebs%defun.utah.edu.uucp@utah-cs.UUCP (Stanley T. Shebs)
Newsgroups: comp.lang.prolog
Subject: Re: BSI standards
Message-ID: <5337@utah-cs.UUCP>
Date: 10 Mar 88 15:12:29 GMT
References: <8803082357.AA01587@decwrl.dec.com> <5334@utah-cs.UUCP> <751@cresswell.quintus.UUCP>
Sender: news@utah-cs.UUCP
Reply-To: shebs%defun.utah.edu.UUCP@utah-cs.UUCP (Stanley T. Shebs)
Organization: PASS Research Group
Lines: 30

In article <751@cresswell.quintus.UUCP> ok@quintus.UUCP (Richard A. O'Keefe) writes:

>	the lack of a _notation_ for characters other than the numbers.
>	PopLog has `x`, DEC-10 Prolog, (some versions of) C Prolog, and
>	Quintus Prolog have 0'x (yes, it's a hack, but there weren't
>	any characters left over),

Notation works for input, but fails for output.  Not so bad for batch
programming, but you get garbage (= mysterious numbers) when listing
a predicate.

>For once I'm not going to express an opinion!  Comparing Pascal code I've
>seen with C suggests that using ORD and CHR a lot isn't a good idea either.

What was it that made it a bad idea?  This is the first time I've heard
this view expressed by a non-assembly programmer.

>I've used Interlisp enough to know that I *definitely* don't want to use
>atoms to represent characters, but I haven't used Common Lisp enough to
>know whether that's better.

In my opinion, character objects is one of the few things that Common Lisp
can't be faulted on!  The first time you get back #\s instead of 115 is
enough to convince anyone that hasn't memorized the ASCII table.  Also we
should not neglect the sense of security gained, when a function refuses to
use a character as an index, or to multiply two characters together (there
are char<->int conversion functions if needed).

							stan shebs
							shebs@cs.utah.edu