This cart is a barebones Forth implementation in 279 tokens. It could be smaller, it could be more usable, but I haven't really touched it in weeks, so here you go. Probably full of bugs.
Features
eval()function- Interpret and compile modes - extend syntax in Forth!
if/then(implemented in Forth)- A few useful comments, including some commented-out utility functions and basic smoke test.
Non-features / shortcomings
else(you can add this in Forth)- Arithmetic (you can add this for 11 tokens per binop, or 9 tokens if you're willing to use valid Lua identifiers as operator names)
- Looping (you can probably add this for the cost of a few arithmetic/comparison operators, then add the syntax in Forth for no token cost)
- Passing args or returning values when calling Lua functions from Forth (depending on how fancy you want to get, probably takes 20-50 tokens for a reasonable wrapper)
[and]are spelled_lband_rbfor some reason.- The inner interpreter works in a non-standard way that will make it hard to call arbitrary Forth from Lua outside of
eval- this is probably worth rethinking.
A few ways to make it smaller
- A few functions could probably be moved from Lua to the initial Forth definitions as-is, although since
:and;depend on them this will be a bit messy. - With the right Forth/Lua binding util, even more functions could probably be moved.
- With some internal representation changes, even
_interpandevalcould probably be (mostly) boostrapped.
Anyway, enjoy. This may not be useful for very much, but the question of how little material you need to bootstrap a reasonable eval is still kind of a fun question.
P#131852 2023-07-11 21:17 ( Edited 2023-07-11 21:23)
[Please log in to post a comment]
