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From: toma@tekgvs.LABS.TEK.COM (Tom Almy)
Newsgroups: comp.lang.misc,comp.software-eng
Subject: Re: :=
Message-ID: <6054@tekgvs.LABS.TEK.COM>
Date: 4 Oct 89 14:58:03 GMT
References: <1989Oct3.182931.518@jarvis.csri.toronto.edu>
Reply-To: toma@tekgvs.LABS.TEK.COM (Tom Almy)
Followup-To: comp.lang.misc
Organization: Tektronix, Inc., Beaverton,  OR.
Lines: 22

In article <1989Oct3.182931.518@jarvis.csri.toronto.edu> malton@csri.toronto.edu (Andrew Malton) writes:
>Apparently := to express the assignment operation was used faute de mieux
>in Algol since the arrow <--- originally chosen for this purpose wasn't
>available on teletypes. Does anyone know a reference for this story?

I used Teletypes (TM) that had the left arrow, and I remember it being on
some early ASCII charts. At one point the ASCII standard was revised and the
left arrow became an underscore.

I used an HP Algol on an early HP minicomputer (2114?) and used the left
arrow for assignment. Also Smalltalk-80 uses the left arrow for assignment;
when you look at the character code, it is the underscore. The APL character
set has a left arrow for assignment as well.

I personally would like to see the left arrow back. It makes more sense
than colon equal (gag, why couldn't they at least have used <- ?) and both
of these are easier to explain than the use of just the equals sign for
assignment.

Tom Almy
toma@tekgvs.labs.tek.com
Standard Disclaimers Apply