Article View: comp.lang.misc
Article #2563Re: ^ considered mysterious
From: David A Keldsen
Date: Wed, 02 Jan 1991 20:08
Date: Wed, 02 Jan 1991 20:08
49 lines
2412 bytes
2412 bytes
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
Technical Details
Message-ID:
<1991Jan2.200832.15723@sq.sq.com>Path:
arc1-ca.pugleaf.net!utzoo!censor!geac!sq!dakReferences:
<21900003@inmet>Show Full Headers
Complete Article Headers
Newsgroups: comp.lang.misc Path: arc1-ca.pugleaf.net!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