Recurse Center Symbolic Differentiation

main.rs

type Real = f32;

#[derive(Clone, Debug)]
struct Polynomial(Vec<Real>);

impl Polynomial {
    fn empty() -> Self {
        Self(vec![])
    }

    fn derive(&self) -> Self {
        if self.0.len() == 0 {
            Self::empty()
        } else {
            let new_coeffs = self.0[1..]
                .iter()
                .enumerate()
                .map(|(new_pow, &coeff)| coeff * (new_pow as Real + 1.0))
                .collect();
            Self(new_coeffs)
        }
    }
}

fn main() {
    // 3 + 4x + 5x^2 + 6x^3
    let mut expression = Polynomial(vec![3.0, 4.0, 5.0, 6.0]);
    for _ in 0..6 {
        println!("{:?}", expression);
        expression = expression.derive();
    }
}