Path: utzoo!attcan!uunet!ncrlnk!ncr-sd!hp-sdd!hplabs!hpfcdc!hpldola!hpctdlb!hpctdls!rbk
From: rbk@hpctdls.HP.COM (Richard Katz)
Newsgroups: comp.lang.misc
Subject: Re: colon-equal vs equal
Message-ID: <3290002@hpctdls.HP.COM>
Date: 22 Dec 88 18:09:12 GMT
References: <3300001@uxg.cso.uiuc.edu>
Organization: Hewlett-Packard CTD, Colo. Spgs.
Lines: 28

>/ hpctdls:comp.lang.misc / phil@uxg.cso.uiuc.edu /  2:36 pm  Dec 20, 1988 /

>How did the := come into being in languages like Algol, Pascal, and Ada?
>I still prefer the way it is in C (and a little lesser so in Rexx and
>Fortran).  My second beef against := is the extra character.  My FIRST
>beef against := is the KeYbOaRd ShIfTiNg I hAvE tO kEeP dOiNg FoR iT.
----------

I don't know how the := came into being, but I don't have any beef
about it.  In fact, I think Pascal use of it is good.  Pascal uses =
as a boolean operator and := as asignment.  First, := seems better
since  i = i + 1 looks real funny.  Also, a nice feature is that
'if ( i := 10 )' will produce a syntax error in Pascal while
'if ( i =  10 )' will produce an assignment in C, usually not
intended.  FORTRAN uses .EQ. to make sure that there is no mixup
between the assignment operator and the comparison operator.  Perhaps 
i <- 10 would make more sense than := although it is slightly more
awkward to type.  Typing the extra character is not that hard and more
than pays for itself by eliminating the occasional typo in Boolean
expressions.

rich katz
hewlett packard
p o box 7050
colorado springs, co
80933-7050

email: rbk@hpctdlb.hp.com