old threaded languages, was Re: Symbolics

Allison J Parent <allisonp(a)world.std.com> wrote: Hi Forth and PostScript are quite similar but I wouldn't say that LISP was a stack based language. It uses stacks but most languages use stacks. In Forth, you have direct control of two stacks as necessary for the language. The differences that contrast the languages are post-fixed versus pre-fixed. Both of these are actually better than in-fixed that is used by most popular languages( flame bate ). Parsing rules are always the same, with no special cases to deal with or ambiguous implementation depended rules. Forth has the advantage that action is read left to right or "Do-it As You See It". LISP has the ability to concatenate several of similar operations like (+ ). LISP has the advantage over Forth in that all parameters are specific in the text. Both can do recursion with equal ease although many early Forth's did not explicitly define it. One of the big advantages of Forth and that is it has flexibility to add new capabilities in high level Forth or low level code and make it seem as though it were part of the language. LISP has a similar ability but the explicit parameter passing often makes the usefulness of this lost in the coding. Oh well, each to there own. IMHO Dwight