Path: utzoo!telly!attcan!uunet!saxony!dgil
From: dgil@pa.reuter.COM (Dave Gillett)
Newsgroups: comp.lang.misc
Subject: Re: He's not the only one at it again!
Message-ID: <287@saxony.pa.reuter.COM>
Date: 31 Jul 90 18:11:52 GMT
References: <25630@cs.yale.edu> <58091@lanl.gov> <3478@goanna.cs.rmit.oz.au> <25681@cs.yale.edu> <1990Jul30.143530.24295@phri.nyu.edu> <25684@cs.yale.edu>
Organization: Reuter:file Inc  (A Reuter Company) Palo Alto, CA
Lines: 27

In <25684@cs.yale.edu> zenith-steven@cs.yale.edu (Steven Ericsson Zenith) writes:

>In article <1990Jul30.143530.24295@phri.nyu.edu>, roy@phri.nyu.edu (Roy
>Smith) writes:
>|>zenith-steven@cs.yale.edu (Steven Ericsson Zenith) writes:
>|>> The use of := distinguishes assignment from equality [...] and IMHO is a
>|>> much nicer solution to the C hack == used to ovecome the same problem.
>|>
>|>why not "<-"?

>My objection to <- would be typographic. Fixed width font versions (widely used
>for program listing) make the visual distance between the < and dash
>exagerated. Functional languages often use -> (see ML, Haskell), 
>and indeed Ease uses -> for type constraint. But I don't really
>like the visual distance between dash and >. The problem is born from a 
>desire to maintain compatibility with the ASCII character set.

It's worth mentioning here that APL (a functional language) uses a symbol for
assignment that looks remarkably like "<-", except that it appears as a single
character.  (APL does not adhere to ASCII....)  This leaves "=" for its usual
role as a comparison predicate.  I have personally observed people learning the
language who found this completely straightforward; the same people had 
previously had difficulty with ":=", "==", and (worst of all!) Micorsoft
BASIC's "=" which means one or the other, depending on context (ouch).

I don't know what J, an ASCII-compatible descendent of APL, uses...
                                   Dave