From:	sands AT clipper DOT ens DOT fr (Duncan Sands)
Subject:	RE: User defined functions
To:	djgpp AT sun DOT soe DOT clarkson DOT edu (djgpp)
Date:	Thu, 15 Sep 94 18:11:12 MET DST

A big thanks to everyone who replied to my question about user defined
functions.  I was ( and still am ) overwhelmed by the helpfulness and
especially by the rapidity of the responses.  These were of three types.

1) use an existing language.  Thanks to DJ, John Davis and Guarionex Morales
   for suggesting bc, slang and tcl respectively.  At first glance slang seems
   to me to offer more: it resembles bc but has many more features; it can be
   embedded easily into a program; like bc what you type is byte compiled, so
   fairly fast.  Unlike bc it only has finite precision arithmetic, but for
   me that's an advantage: it's all I want and is faster than infinite
   precision arithmetic.  Recursive function definitions aren't allowed,
   unlike bc ( am I right John? ).  I haven't looked closely at tcl but John
   tells me slang is about 10 times faster than tcl.  However Guarionex describes
   tcl as being stuffed with useful features, and better than bison wrestling.
   tcl and slang compile under djgpp; I don't know whether bc has been ported
   to msdos.
   - bc is available from prep.ai.mit.edu and other GNU mirrors.
   - slang is available from amy.tch.harvard.edu
   - tcl is available from harbor.ecn.purdue.edu

2) gut an existing program.  The favorite candidate for evisceration was
   gnuplot, suggested by Andy++ "bonne chance" ( merci pour l'encouragement! )
   Rothfusz and Gordon Hogenson.  Since no other program got a vote I guess
   this shows the love ( hate? ) people have for gnuplot.  Unfortunately the
   guts of gnuplot are fairly twisted; I doubt I have the courage to operate.
   gnuplot is available for msdos.  There is a makefile for djgpp, but apparently
   problems with using the result.
   - gnuplot is available from prep.ai.mit.edu and other GNU mirrors.

3) use a custom mathematical function parser.  Christian Burger suggested
   formu200.zip, available from SimTel.  Michail Rozman also suggested SimTel.
   I found mathfc23.zip, parser21.zip and tsfunc13.zip; I have no idea what
   these are ( the same goes for formu200 ): I haven't even unzipped them yet!
   Kevin Rogovin (kwr AT risc DOT rockwell DOT com) has a parser written in C++ which he's
   offered to send me.  Tilmann Haeberle (til AT zentrum DOT phys DOT chemie DOT tu-muenchen DOT de)
   also has a parser, originally from a Turbo C demo and extended by him.
   - mathfc23.zip, parser21.zip and tsfunc13.zip are available from SimTel,
     sorry, I've forgotten which subdirectories.  oak.oakland.edu is the primary
     SimTel mirror.
   - formu200.zip should be available from SimTel in the "c" subdirectory but it
     doesn't seem to be there.  An archie search got it though.  It is listed in
     the index of the "c" subdirectory but not in the main index.

Thanks again,

Duncan Sands.

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