Newsgroups: comp.lang.apl
Path: watmath!ljdickey
From: ljdickey@math.uwaterloo.ca (L.J. Dickey)
Subject: Re: branching in proposed ISO standard
Message-ID: <C19BBx.4vC@math.uwaterloo.ca>
Keywords: branching goto ISO APL flow control structure:w
Organization: University of Waterloo
References: <abalje47.727565873@ursa> <1993Jan21.155458.21218@nntpd2.cxo.dec.com> <1993Jan22.001626.10902@csi.jpl.nasa.gov>
Date: Fri, 22 Jan 1993 13:11:56 GMT

In article <1993Jan22.001626.10902@csi.jpl.nasa.gov> sam@csi.jpl.nasa.gov (Sam Sirlin) writes:
>
>In article <1993Jan21.155458.21218@nntpd2.cxo.dec.com>, mark@11srus.enet.dec.com (Mark Eklof) writes:
>|> 	If you mean things like if-then-else, and such, they aren't intended
>|> to be there.  I'm not aware of any APL implementations that include them, and
>|> I don't recall proposals for them.

>Actually there have been some in the literature. I like the ideas of
>FHD van Batenburg, APL91 regarding dyadic .goto. J has some as well.

Yes, that fine article has received a lot of attention, and it is not
the is not the only one on the subject.  But I think that the meaning
of "proposal" intended by Mark in this context is somewhat more
formal.  The work of the ISO APL Working Group in the development of
Committee Draft 1, (now available by anonymous ftp from
watserv1.uwaterloo.ca), has been to work from proposals that were
submissions from various national standards bodies.  I suspect that it
was these proposals that Mark was referring to.  Readers will likely be
interested to know that the ISO APL Working Group restricted itself to
adding only features to the previous standard that exit in current
implementations.  This is not a rule that other programming language
standards groups have stuck to, and it is not clear that the APL group
will stick to it in the future.  So, in this context, and with the
exception of Quad-EA, there were no proposals on "if-then-else" or
"while-do", or other control structures.

I would like add that the subject of structuring APL code is currently
one of great interest, and that several people have been working and
writing on it.  I believe that it is likely that more than one
paper presented at APL93 will be on this topic.

Lee Dickey

-- 
Prof. Leroy J. Dickey, Faculty of Mathematics, U of Waterloo, Canada  N2L 3G1
   Internet:      ljdickey@math.UWaterloo.ca
                  ljdickey@math.waterloo.edu
   UUCP:          ljdickey@watmath.UUCP
