James H.Cloos Jr. on Sun, 12 Oct 2003 19:14:54 -0400

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Re: reverse polish

>>>>> "Bill" == Bill Allombert <allomber@math.u-bordeaux.fr> writes:

Bill> FWIW, there is a complete HP48 emulator available.

Of course, but I want something easier to extend and that runs native
on the various platforms rather than in emulated saturn.

Bill> GP has functions taking variables number of argument and this is
Bill> not compatible with rpn.

The 48's user-lang and system rpl both also have functions that take
a variable number of args.  The trick is to have the top arg on a
grow-down stack (or the bottom arg on a grow-up stack) be a count of
how many more args to pop.

There will be a bit of work to determine which functions are affected
and create a syntax that Does The Right Thing in each case, of course,
but that is not itself a contraindication.

Bill> Outside that, interfacing a rpn with
Bill> libpari is easy to do once you understand how PARI works,
Bill> especially the way memory is handled.

Cool.  I'll start reading through the library then and see what I can
put together.