Seven Obscure Languages in Seven Weeks

Discovering Recursion

Forth has a return stack and four types of loops. But does Forth have recursion? It depends on whom you ask. “Clean” FORTH-79 doesn’t directly support recursion. However, you can implement recursion yourself with the help of R>, >R, and similar words. It sounds like a cool do-it-yourself project. If you’re not much into DIY, consider using fig-Forth with the word RECUR (in some dialects, MYSELF)—or, better, revert to Gforth with RECURSIVE.

The word RECURSIVE immediately follows the name in a new word definition. It creates a temporary entry in the dictionary, to which the rest of the definition can refer. If you provide no such entry, attempting to use a word within its definition will cause an Undefined word error. ...