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Ron,
Indeed, I had noticed the "pseudo" qualifier in the subject. I hadn't
had time to look at the code previously, but I still had to rise to
the bait. I knew whom you were trolling for! It was worth it just
to get the LOL.
But after a cursory look at the article, I would have to state this:
The authors are wrong that SAS does not have a stack and maintain
local and global variable assignments. OK, the base language does
not provide these services. But the macro language itself does
indeed provide these services. Thus, for some of the work which I do
in which I need to nest loop after loop after loop to depth specified
at runtime, the macro language does a terrific job of recursion.
But I am not manipulating data recursively. I am recursively
manipulating the code which manipulates the data. This is important
for anyone monitoring this thread to understand. I know that Ron
knows all this. For anyone new to SAS programming who is familiar
with recursion in other languages, recursion in SAS may not be as
useful. But in its proper place, there is room for macro recursion
in SAS. Unfortunately, the Observations article which Ron stumbled
on does not actually effect recursion, so the utility of macro
recursion is not really displayed.
But, maybe I'll convince you yet, Ron, that SAS does have true
recursive programming capability! At least you were interested in
looking at the Observations article. Still, it was probably the
pseudo qualifier which convinced you to take a look. (Sigh.)
Dale
--- "Fehd, Ronald J." <rjf2@CDC.GOV> wrote:
> > From: Dale McLerran [mailto:stringplayer_2@YAHOO.COM]
> > OK, who is the imposter who has hacked Ron's account?! It couldn't
> > be the macro-meister himself who posts something positive about
> > recursion in the SAS language! ;)
>
> LOL I knew I'd flush you out, Dale.
> as the subject says: PSEUDO-recursive
> Fascinating article, as he says:
> "... implement some of that [razzle-dazzle] stuff
> they showed you in Pascal."
>
> I wonder if we could put in a loop for the labels
> and make it work with any depth?
>
> > --- "Fehd, Ronald J." <rjf2@CDC.GOV> wrote:
> > > Whilst cruising the SAS website recently I came across this gem.
> > > Who was I taking to task a while back for writing a recursive
> macro?
> > > Observations
> > > A Pseudo-Recursive SAS Macro
> > > William E. Benjamin , Jr.
> > >
> >
>
http://www.sas.com/service/library/periodicals/obs/obswww18/index.html
> > >
> > > Ron Fehd the macro maven CDC Atlanta GA USA RJF2@cdc.gov
> >
=====
---------------------------------------
Dale McLerran
Fred Hutchinson Cancer Research Center
mailto: dmclerra@fhcrc.org
Ph: (206) 667-2926
Fax: (206) 667-5977
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