Jane Street OCaml Challenge: Pattern Matching

match ... with lets us compare values to patterns.

let is_superman x = match x with | "Clark Kent" -> true | _ -> false

You can also match on multiple values at once:

let is_same_person x y = match x, y with | "Clark Kent", "Superman" | "Peter Parker", "Spiderman" -> true | _ -> false

Your Turn

Write a function using pattern matching that returns true if a number is non-zero.

let non_zero x = failwith "For you to implement"

let%test "Testing non_zero..." = Bool.( = ) false (non_zero 0)

let%test "Testing non_zero..." = Bool.( = ) true (non_zero 500)

let%test "Testing non_zero..." = Bool.( = ) true (non_zero (-400))

Write a function that returns true if both inputs are non-zero.

let both_non_zero x y = failwith "For you to implement"

let%test "Testing both_positive..." = Bool.( = ) false (both_non_zero 0 0)

let%test "Testing both_positive..." = Bool.( = ) false (both_non_zero 0 1)

let%test "Testing both_positive..." = Bool.( = ) false (both_non_zero (-20) 0)

let%test "Testing both_positive..." = Bool.( = ) true (both_non_zero 400 (-5))