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use num_traits::Pow;
pub type FracSize = u16;
#[derive(Debug)]
pub struct Program {
pub fractions: Vec<(FracSize, FracSize)>,
pub initial: u64,
}
impl Program {
// http://lomont.org/posts/2017/fractran/
// A lesser known Conway FRACTRAN program is FIBONACCIGAME:
// `{17/65, 133/34, 17/19, 23/17, 2233/69, 23/29, 31/23, 74/341, 31/37, 41/31, 129/287, 41/43, 13/41, 1/13, 1/3}`
// Starting with `78*5^(n-1)`, it halts on `2^Fn` where Fn is the nth [Fibonacci number]
pub fn fibonacci(i: u32) -> Program {
Program {
fractions: vec![
(17, 65),
(133, 34),
(17, 19),
(23, 17),
(2233, 69),
(23, 29),
(31, 23),
(74, 341),
(31, 37),
(41, 31),
(129, 287),
(41, 43),
(13, 41),
(1, 13),
(1, 3),
],
initial: 78 * 5u64.pow(i),
}
}
}
pub trait FractranEngine<Value>: IntoIterator<Item = Value>
where
Value: From<u64>,
{
}
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