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From: mwm@pa.dec.com (Mike (My Watch Has Windows) Meyer)
Newsgroups: comp.lang.rexx
Subject: Re: Iterating on Stems
Message-ID: <MWM.91Mar11140036@raven.pa.dec.com>
Date: 11 Mar 91 20:00:36 GMT
References: <1991Mar9.215906.4976@ssd.kodak.com>
Sender: news@pa.dec.com (News)
Followup-To: comp.lang.rexx
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Lines: 45
In-Reply-To: jeffv@bisco.kodak.com's message of 9 Mar 91 21:59:06 GMT

In article <1991Mar9.215906.4976@ssd.kodak.com> jeffv@bisco.kodak.com (Jeff Van Epps) writes:
   I solved it by storing the keys at the same time as the data, in a more
   normal array (keys.1  keys.2  keys.3  etc.), with a count of how many keys
   have been processed so far.  But this strikes me as a kludgy workaround for
   a missing language feature.  Does the language feature exist and I just
   missed it??

That's pretty much the canonical way to do things. When I asked an
implementer about this, the answer was:

	"Because it's not a simple problem".

In Perl, it's simple - you have a one dimensional array, and are done
with it. In Rexx, you have multi-diminsional arrays. It's not uncommon
to do things like, though this is extreme):

array.index			/* Type information */
array.index.name		/* print name */
array.index.function		/* Name of function to invoke */
array.index.number		/* Numeric value */
array.index.string		/* String value */
array.index.multivalue		/* Multivalued object. */
array.index.multivalue.1	/* Type for this value */
array.index.multivalue.1.{function,number,string,multivalue}
array.index.multivalue.2
etc.

So, what would you have a Rexx version of "each(months)" return? The
list of values index can take on? That gives you all named objects,
but makes dealing with the multi-valued objects somewhat harder. The
list of all complete stems? That gives you everything, but requires
filtering them after the fact.

BTW, if you can come up with a good solution, I believe that people
who are on - or have the ear of people who are on - the ANSI Rexx
committee are listening in. So it may show up in a later version.

	<mike


--
He was your reason for living				Mike Meyer
So you once said					mwm@pa.dec.com
Now your reason for living				decwrl!mwm
Has left you half dead