How would one code an application in Forth (or Factor)?

Question

I'm potentially interested in exploring a stack-based language like Forth (or Factor). What I'd like to see is how an application might be built from the ground up, step by step. The tutorials I've found are rudimentary and are not helping me to understand the bigger picture. It's confusing to think of how one might manage the stack when dealing with lots of parts.

I've always thought (maybe wrongly) that a good way to learn a language would be to use it to write a Roguelike game. I'm having trouble trying figure out how one would juggle a lot of things on a stack: a maze, dozens of creatures, treasures, character stats, etc.

Answer 1

I'd point you to Factor rather than pure Forth; there are plenty of sample apps, GUIs, web apps, etc. If you're specifically interested in a web framework, look at Furnace.

Ultimately I don't understand the question; what does being stack-based have to do with getting anything done? Back in the old days it was the language of choice for embedded systems; I wrote everything from cereal boxing robots to calculators to... well, mostly everything.

Answer 2

In some sense, all languages are equivalent; you write a program by breaking a problem down into smaller pieces, then you code up those pieces and make them all work together. Forth has unusual syntax features, but it's still a programming language.

In fact, Forth places a great deal of power at your fingertips, much as Lisp does. In Lisp, using "macros", you can write your own control structures that are just as good as anything built-in; in Forth, you can do the same.

If you are interested in finding out more about Forth, I suggest you get the classic books Starting Forth and Thinking Forth by Leo Brodie.

Oh! Google just told me that both books are available free online now:

http://www.forth.com/starting-forth/

http://thinking-forth.sourceforge.net/