Path: utzoo!attcan!uunet!lll-winken!lll-lcc!ames!mailrus!purdue!decwrl!labrea!Portia!Jessica!alderson
From: alderson@Jessica.stanford.edu (Rich Alderson)
Newsgroups: comp.lang.misc
Subject: Re: Algol-style assignment operators
Summary: 30 years old
Message-ID: <4437@Portia.Stanford.EDU>
Date: 22 Dec 88 01:21:36 GMT
References: <1126@etive.ed.ac.uk> <208100002@s.cs.uiuc.edu> <868@mcrware.UUCP> <8008@aw.sei.cmu.edu> <GARY.88Dec15142623@milo.mcs.clarkson.edu> <88Dec16.100919est.4327@turing.toronto.edu> <9235@ihlpb.ATT.COM> <2185@eos.UUCP>
Sender: news@Portia.Stanford.EDU
Reply-To: alderson@Jessica.stanford.edu (Rich Alderson)
Organization: Stanford University
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In article <2185@eos.UUCP> eugene@eos.UUCP (Eugene Miya) writes:

>On ":=" versus "=": Altos had an backward arrow assignment key, not "<-" for
>Mesa.  (this could correspond to other language arrows (UP) ^ and (RIGHT)
>"->".)  Just standardize some extra characters.  8-) It will never happen.

The original Algol specification was for TWO languages: The one most people
think of as Algol 60 was intended as the machine-readable version, using
current ("IBM") keypunches.  The other, intended for algorithm specification in
print, used a different character set.

Specifically, the assignment operator in the latter was an arrow pointing to
the left.  The two-character form ":=" was chosen to disambiguate assignment
from the Boolean equality operator "=".