rudus/src/main.rs

// an implementation of Ludus

// curently left undone (and not adding for a while yet):
// * sets
// * interpolated strings & string patterns
// * pkgs, namespaces, imports, `use` forms
// * with forms
// * test forms
// * ignored words

// todo:
// * [x] rewrite fn parser to use chumsky::Recursive::declare/define
//   - [x] do this to extract/simplify/DRY things like tuple patterns, fn clauses, etc.
// * [x] Work around chumsky::Stream::from_iter().spanned disappearing in most recent version
// * [x] investigate using labels (which is behind a compiler flag, somehow)
// * [ ] wire up Ariadne parsing errors
// * [ ] validation
// * [x] break this out into multiple files
// * [x] write a tree-walk VM
//   - [x] learn how to deal with lifetimes
//   - [x] with stack mechanics and refcounting
//   - [ ] with tail-call optimization (nb: this may not be possible w/ a TW-VM)
//   - [ ] with all the necessary forms for current Ludus
//     * [ ] guards in match clauses
//     * [x] `as` patterns
//     * [ ] splat patterns in tuples, lists, dicts
//     * [ ] splats in list and dict literals
//     * [ ] `loop` and `recur`
//     * [ ] string patterns
//     * [ ] string interpolation
// * [~] write `base` in Rust
// * [ ] turn this into a library function
// * [ ] compile this into WASM
// * [ ] perf testing

use chumsky::{input::Stream, prelude::*};
use std::rc::Rc;

mod spans;

mod lexer;
use crate::lexer::*;

mod value;
use crate::value::*;

mod parser;
use crate::parser::*;

mod vm;
use crate::vm::*;

mod base;
use crate::base::*;

pub fn main() {
    let src = "
fn fancy_add {
    () -> 0
    (n as :number) -> n
    (x as :number, y as :number) -> add (x, y)
}

fn fancy_sub {
    () -> 0
    (n as :number) -> n
    (x as :number, y as :number) -> sub (x, y)
}

fn fib {
   (1) -> 1
   (2) -> 1
   (n) -> fancy_add(
       fib (fancy_sub (n, 1))
       fib (fancy_sub (n, 2))
   ) 
}

fib (30)
    ";
    let (tokens, lex_errs) = lexer().parse(src).into_output_errors();
    if lex_errs.len() > 0 {
        println!("{:?}", lex_errs);
        return ();
    }
    let tokens = tokens.unwrap();
    let to_parse = tokens.clone();
    // for (token, _) in tokens {
    //     println!("{}", token)
    // }
    let (ast, _) = parser()
        .parse(Stream::from_iter(to_parse).map((0..src.len()).into(), |(t, s)| (t, s)))
        .unwrap();
    // println!("{}", ast);

    let mut ctx = base();

    let result = eval(&ast, &mut ctx).unwrap();

    println!("{}", result);
}