Rust code shared from the playground

playground.rs

macro_rules! siaf {
    (|$($parm:ident),* $(,)*| $body:expr) => {{
        /* ensure no captures */ let closure: fn($($parm: _),*)->_ = |$($parm),*| $body;
        (closure)($($parm),*)
    }}
}

fn compute_g(a: i32, b: i32, c: i32) -> i32 {
    let d = siaf!(|a, b| a + c);
    let (e, f) = siaf!(|d| (d - 1, d + 1));
    let g = siaf!(|c, e, f| c + e + f );
    g
}

fn main() {
    println!("{}", compute_g(1, 2, 3));
}