import support::test

private fun fibo(n: i32, x1: i32, x2: i32): i32 = {
  if (n > 0) {
    fibo(n - 1, x2, x1 + x2)
  } else {
    x1
  }
}

private fun fiboPatternMatching(n: i32, a: i32, b: i32): i32 =
  match n {
    case 0 -> a
    case 1 -> b
    else   -> fibo(n - 1, b, a + b)
  }


fun fib(n: i32): i32 = fibo(n, 0, 1)
fun fibPatternMatching(n: i32): i32 = fiboPatternMatching(n, 0, 1)

fun factorial(n: i32): i32 =
  if (n >= 1)
    n * factorial(n - 1)
  else
    1




#[export] fun main(): void = {
  START("fibonacci")

  mustEqual(fib(46), 1836311903, "fib(46) must be 1836311903")
  mustEqual(fibPatternMatching(46), 1836311903, "fibPatternMatching(46) must be 1836311903")

  END()

  START("factorial")

  mustEqual(factorial(10), 3628800, "factorial(10) must be 3628800")

  END()
}