Rudimentary Forth environment, heavily based on Jonesforth.

The Rust VM has 45 opcodes corresponding to Forth words, mostly for arithmetic, memory manipulation and code generation. The rest of the vocabulary (a further 88 words at present, including the non-primitive stack manipulation operations, logical operators, control structures and string handling) is implemented in Forth.

This was a learning project and is unlikely to be useful for any practical purpose. In particular, error handling is pretty minimal and only ASCII is supported.

You can try it out by running the following:

." Hello, world!"

: fac dup 1 > if dup 1- recurse * then ;
10 fac .

Or, if you prefer iteration to recursion:

: fac 1 swap begin dup 1 > while tuck * swap 1- repeat drop ;
10 fac .