lbForth VS subleq

Forth compiler in 159 lines of Lisp and C

Probably what I would do is write a minimal forth interpreter in C, and then use that and a few core words to bootstrap the rest of the system. It is a bit more complex than that, but here is the software which does it.https://github.com/larsbrinkhoff/lbForth

I wrote a Forth interpreter for a SUBLEQ machine (https://github.com/howerj/subleq), and for a bit-serial machine (https://github.com/howerj/bit-serial), both of which do not have a function call stack which is a requirement of Forth. SUBLEQ also does not allow indirect loading and stores as well and requires self-modifying code to do anything non-trivial. The approach I took for both machines was to build a virtual machine that could do those things, along with cooperative multithreading. The heap, if required, is written in Forth, along with a floating point word-set (various MCUs not having instructions for floating point numbers is still fairly common, and can be implemented as calls to software functions that implement them instead).

I would imagine that other compilers took a similar approach which wasn't mentioned.

I've already posted about the implementation on Forth, but you might want to see how such a system is created in detail along with the design decisions and compromises. The source code can be freely viewed at https://github.com/howerj/subleq.