pseudo-lisp-in-rust.rs

macro_rules! foo {
    ($a: literal ) => {
      $a
    };
    ($op:tt $a:literal $b:tt) => {
        foo!($op ($a) $b)
    };
    ($op:tt $a:tt $b:literal) => {
        foo!($op $a ($b))
    };
    ($op:tt $a:tt $b:tt) => {
        foo!$a $op foo!$b
    };
}
fn main() {
let a = foo!(5);
  let a = foo!(
      * (+ (+ 1 1) (* 2 3)) 4
  );
  println!("kotek = {}", a);
}