gorf_blc/
lib.rs

1#![no_std]
2extern crate alloc;
3use alloc::boxed::Box;
4use core::iter::once;
5
6use lambda_calculus::Term;
7
8pub fn encode(a: &Term) -> Box<dyn Iterator<Item = bool> + '_> {
9    match a {
10        Term::Var(a) => Box::new((0..=*a).map(|_| true).chain(once(false))),
11        Term::Abs(term) => Box::new([false, false].into_iter().chain(encode(&term))),
12        Term::App(a) => {
13            let (a, b) = &**a;
14            return Box::new([false, true].into_iter().chain(encode(a)).chain(encode(b)));
15        }
16    }
17}
18pub fn decode(a: &mut (dyn Iterator<Item = bool> + '_)) -> Option<Term> {
19    Some(match a.next()? {
20        true => {
21            let mut i = 0;
22            while a.next()? {
23                i += 1
24            }
25            Term::Var(i)
26        }
27        false => match a.next()? {
28            false => Term::Abs(Box::new(decode(a)?)),
29            true => Term::App(Box::new((decode(a)?, decode(a)?))),
30        },
31    })
32}
gorf_blc/lib.rs

gorf_blc/
lib.rs
