A step beyond Rust's pattern matching(radiki.dev)

  while matches!(iterator.next(), Some((a, b)) if a + 1 == b) {
      println!("Hello!");
  }

  while match iterator.next() {
      Some((a, b)) if a + 1 == b => {
          println!("{a}, {b}");
          true
      },
      _ => false
  } {}

  1> (match (@a @(= (+ a 1))) '(1 3) a)
  ** match: (@a @(= (+ a 1))) failed to match object (1 3)
  1> (match (@a @(= (+ a 1))) '(1 2) a)
  1

  2> (match (@a @(+ a 1)) '(1 3) a)
  1

  3> (match (@a @(< a @b)) '(1 3) (list a b))
  (1 3)

  4> (match (@a @(< a @b)) '(1 0) (list a b))
  ** match: (@a @(< a @b)) failed to match object (1 0)

  1> (defmatch + (. args) ^@(= (+ ,*args)))
  +

  2> (match (@a @(+ a 1)) '(1 2) a)
  1
  3> (match (@a @(+ a 1)) '(1 3) a)
  ** match: (@a @(+ a 1)) failed to match object (1 3)

    match user {
       ImportUser{id, account: {AccountData: email, ..}, ..
    } => println({id}: {Some(email)}),
        _ => println("Not an ImportUser or has no mail")
    }

  fn infallible() -> Result<u8, !>{
      Ok(1)
  }
  
  fn match_infallible(){
      let Ok(x) = infallible();
  }

    let the_data = vec![
      (1, 2),
      (2, 2)
      (2, 3),
      (5, 7),
      (8, 8)];

    for (a, b) in the_data {
        println!("({}, {})", a, b);
    }
    
    // prints
    // (1, 2)
    // (2, 3)
    // (5, 7)
    // (8, 8)

  while let Some((a, a + 1)) = iterator.next() {
    println!("({}, {})", a, b);
}