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From: wagner@pucc.Princeton.EDU (John Wagner)
Newsgroups: comp.lang.rexx
Subject: Re: A Suggestion For Adding Function Pointers To REXX
Message-ID: <13725@phoenix.Princeton.EDU>
Date: 9 Feb 90 00:28:12 GMT
References: <26705@cup.portal.com> <26534@cup.portal.com> <25545@cup.portal.com>
Sender: news@phoenix.Princeton.EDU
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Will, A piece of information  you may not know:

In the pre-VM/SP version of REXX (the IBM internal use only version also
available to some groups doing joint research with IBM) included an interface that could have been used to create call by value and call by reference.  It was a piece of the EXECCOMM interface that was removed
by development when the product was released.

You can still do call by value using the VALUE() function.  Call by
reference would require a handle that it is no longer possible to create
in SAA without modifying the interpreter.  Since the interpreter is now
entirely without source code (and disassembly is explicityly disallowed
by the license agreement signed by the site) it is unlikely that an user
site will make the effort to implement what you are looking for even if
they think it is a good idea.

This leaves you with the option of convincing IBM to do it, convincing
some third party vendor with an existing implementation to do it, or
writing your own interpreter.  While the last option might be fun, unless
someone is really willing to push it in the IBM world, it is likely to fail
irrespective of the quality of the product.

I keep wondering why you aren't looking at PL/I.  Your goal (given that
INTERPRET is not to be used) is effectively making REXX into PL/I.
Or as an alternative, libraries of REXX functions that are included 
into the code by a macro processor style operation (some companies have
developed procedures in this direction).