Newsgroups: comp.lang.misc
Path: utzoo!censor!geac!sq!dak
From: dak@sq.sq.com (David A Keldsen)
Subject: Re: ^ considered mysterious
Message-ID: <1991Jan2.200832.15723@sq.sq.com>
Organization: SoftQuad Inc.
References: <21900003@inmet>
Date: Wed, 2 Jan 91 20:08:32 GMT
Lines: 50

stt@inmet.inmet.com writes:

[a far too lucid explanation, so I'll clutter it up a bit]

>Algol 60, Basic, and many other languages have used the
>circumflex, or up-arrow (as it used to print on some teletypes)
>to indicate exponentiation.  It has the obvious superscript
>connotation, and so is very natural.  

Algol 60 is very particular about this (see the "Report on the Algorithmic
Language Algol 60" CACM 6, 1, 1963 1-17.)

The "reference language" specifies an "up arrow" and the "publication
language" was supposed to use superscripts; as stt says, the
connotation is obvious and natural.  Implementors were permitted to use
other mappings; again, the circumflex was typical and and obvious
substitute for the up-arrow.  This falls under the "hardware
representations:"

	1. Each one of these is a condensation of the reference language 
	   enforced by the limited number of characters on standard input 
	   equipment.
	2. Each one of these uses the character set of a particular computer 
	   and is the language accepted by a translator for that computer.
	3. Each one of thesemust be accompanied by a special set of rules for 
	   transliterating from Publication or Reference language.
(from the Report, p. 3)

Other troublesome operators in Algol 60 include multiplication (who has
that big elementary-school X available?) subset-of, logical-and, logical-or,
not...

>The fact that circumflex
>doesn't appear on 026 and 029 keypunches (if my memory
>serves me) must have inhibited its use in the US for 
>card-oriented languages like Fortran.  It also doesn't
>appear on IBM 3270 terminals, which are essentially
>glass-029s (:-o).

In their favor, IBM did at least have a negation operator that looks just
like the one in the Algol 60 reference language.  Ah, well.  Nostalgia
isn't what it used to be...

Regards,
Dak
-- 
David A. 'Dak' Keldsen of SoftQuad, Inc. email: dak@sq.com  phone: 416-963-8337
"It's a poor sort of memory that only works backwards," the Queen remarked.
    -- _Through the Looking Glass & What Alice Found There_ by Lewis Carroll