partial_application_v2.rs

use partial_application::partial;

enum Ops {
    Add, Sub, Div, Mult
} 

fn calc(op: Ops, x: i32, y: i32) -> i32 {
    match op {
        Ops::Add => x + y,
        Ops::Sub => x - y,
        Ops::Div => x / y,
        Ops::Mult => x * y
    }
}

fn main() {
    let xs = [10, 30, 42, 4, 6];
    let qs: Vec<i32> = xs
        .iter()
        .cloned()
        .map(partial!(calc => Ops::Div, _, 2))
        .map(partial!(calc => Ops::Mult, _, 3))
        .collect();

    assert_eq!(qs, [15, 45, 63, 6, 9]);
}