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From: billw@hpcvra.cv.hp.com. (William C Wickes)
Newsgroups: comp.sys.handhelds
Subject: Re: progamming question
Message-ID: <25590133@hpcvra.cv.hp.com.>
Date: 11 Apr 91 23:13:31 GMT
References: <1991Apr10.191353.18942@bigsur.uucp>
Organization: Hewlett-Packard Co., Corvallis, OR, USA
Lines: 20

Given x and F on the stack, where x is any argument, and F is a
function of one argument (user-defined or built-in), the following
program returns 'F(x)':

%%HP: T(3)A(R)F(.);
@ x F -> 'F(x)'
\<< SWAP -> a
   \<< 'a' SWAP EVAL                   @ 'F(a)'
       'a' a 2 \->LIST \|^MATCH DROP   @ 'F(x)'
   \>>
\>>

To put a built-in function F on the stack, execute { F } 1 GET.  You
can also build this logic into the program above, and use { F } as the
argument.

For user-defined functions, you also can use SWAP 1 \->LIST SWAP APPLY.

Bill Wickes
HP Corvallis