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From: darrelj@sdcrdcf.UUCP (Darrel VanBuer)
Newsgroups: net.works
Subject: Re: Time for keyword parameters for prog. lang's
Message-ID: <987@sdcrdcf.UUCP>
Date: Wed, 11-Apr-84 09:20:21 EST
Article-I.D.: sdcrdcf.987
Posted: Wed Apr 11 09:20:21 1984
Date-Received: Fri, 13-Apr-84 20:40:16 EST
References: <3783@utcsrgv.UUCP>
Reply-To: darrelj@sdcrdcf.UUCP (Darrel VanBuer)
Organization: System Development Corporation, Santa Monica
Lines: 18

MIT Lisp Machine Lisp (available in commercial versions from Symbolics and
LMI) has a mixture of positional and keyword parms (so did JCL and assembler
macros in IBM 360 and successors).  Generally the convention is that the
arguments used all the time (and thus somewhat well known) are usually
positional, while the usually large number of "optional" arguments are
done with keywords.  The value of missing arguments defaults to NIL or
to a value which is part of the procedure declaration (defaults in 360
macros were zero and the null string unless specified as DSORG=PS or
DENSITY=2 etc).  

-- 
Darrel J. Van Buer, PhD
System Development Corp.
2500 Colorado Ave
Santa Monica, CA 90406
(213)820-4111 x5449
...{allegra,burdvax,cbosgd,hplabs,ihnp4,sdccsu3,trw-unix}!sdcrdcf!darrelj
VANBUER@USC-ECL.ARPA