1  
 2  contract Identity =
 3  
 4    function zip_with(f, xs, ys) =
 5      switch((xs, ys))
 6        (x :: xs, y :: ys) => f(x, y) :: zip_with(f, xs, ys)
 7        _ => []
 8  
 9    // Check that we can use zip_with at different types
10  
11    entrypoint foo() =
12      zip_with((x, y) => x + y, [1, 2, 3], [4, 5, 6, 7])
13  
14    entrypoint bar() =
15      zip_with((x, y) => if(x) y else 0, [true, false, true, false], [1, 2, 3])
16