Forthkit

Inspired by Lispkit, build your own Forth from scratch.

0. Learn what Forth is by building a pixel library and turtle graphics in gforth
   • Write a console Pixel library using Unicode Braille characters
   • Use this to do turtle graphics
1. Make register-based "hardware" (VM in Forth) and assembler
2. Use the assembler to build a kernel (and boot image)
3. Rewrite the VM in C and abandon gforth
4. TODO: Bootstrap the rest of the language
   • TODO: Port pixel library
   • TODO: Port turtle graphics (using fixed point)
   • TODO: Port kernel itself
   • TODO: Achieve meta-circularity! That is, build the kernel using gforth, then use that kernel to build a new (identical for now) kernel. Iterate.
   • TODO: Re-write kernel in more natural Forth syntax
5. TODO: Build an inner interpreter and replace calls
   • TODO: Experiment with direct/indirect threading
   • TODO: Experiment with using the return stack for locals and loop counters
   • TODO: Implement remaining Forth control structures
   • TODO: Explain does> in the context of direct/indirect threading
   • TODO: Discuss/implement token threading
   • TODO: Discuss separate headers (e.g. fall-through definitions, save memory, ...)
   • TODO: Discuss separate host/target (like Brief)
6. TODO: Make more new "hardware" - a stack machine this time
7. TODO: Port our Forth to this - see how the inner interpreter goes away
   • TODO: Use block-style disk I/O
8. TODO: Move to a colorForth style variant (less syntax, no immediate words, etc.)
9. TODO: Build a block editor and stop using Vim
   • TODO: We've now bootstrapped a whole "OS" for ourselves!
10. TODO: Discuss non-standard ideas:
    • Quotations ([: ... :]), combinators, (Factor, Joy, Brief, ...)
    • if as a combinator
    • Recursion as only control flow
11. TODO: Discuss other execution models (e.g. stack/continuation, XY, Brief, ...)
12. TODO: More ideas
    • VT100 library
    • Snake game
    • Tetris game
    • Discuss optimizing compilation