Forth-With

In Volume 1, No. 5 of Sync Ware News I approached you with the idea of presenting an introductory/ tutorial column on the FORTH language. If you missed my introduction to FORTH article in Volume 1:3, I suggest you go back and read that. Contact Sync Ware News for back issue availability if you need to. It will give you some good background information, and help explain why and how the pieces fit.

“Forth is like Pascal because they are both structured, with none of the ‘can of worms’ GOTOs and GOSUBs of BASIC and Fortran.” True, except FORTH is structured bottom-up instead of top-down like Pascal. In FORTH you start with primitives (machine/assembler-like basic words) and define increasingly complex words from them until the last word defined is your program.

“FORTH is like C because they both are designer-type languages.” True, except FORTH is both extensible and interactive. In C, to use a new idiom you must link to it and recompile, whereas in FORTH you merely define the needed word. Further, FORTH is interactive. This means as you develop a new word you may test it in the interpreter mode just like you do in BASIC. You have no interpreted mode in C.

“FORTH is like LISP in that they are both used in artificial intelligence efforts.” True, but this is really a LISP stronghold. It must be noted, though, that SAVVY from Excalibur in Albuquerque, NM is the only commercial AI system available for micros – at least as far as I know – and it is written in FORTH. Why? Because FORTH is compact. LISP is memory intensive!

By now you are asking, “Just what is FORTH like?” FORTH is like FORTH and nothing else – it’s that simple. It has been shown that people who have never been exposed to a procedural language like BASIC, Fortran, Pascal, etc. grasp FORTH almost immediately. This is the one language, apparently, in which prior experience with other languages does not help – that experience may, in fact, hamper.

Since all Sync Ware News readers are ace BASIC users we are resorting, next installment probably, to presenting FORTH in terms of BASIC. A lot will depend on your response. Want to learn FORTH? Come on in, have a seat. If you have a FORTH kernel, make your Sinclair/ Tim ex a FORTH terminal and start playing with a very exciting language. Let me know what things you want me to bring to the party.

Thanks. Hope to hear from you soon.