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@bmarcot
Last active December 16, 2015 03:48
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trait List[T] {
def isEmpty: Boolean
def head: T
def tail: List[T]
}
class Cons[T](val head: T, val tail: List[T]) extends List[T] {
def isEmpty: Boolean = false
}
class Nil[T] extends List[T] {
def isEmpty: Boolean = true
def head: Nothing = throw NoSuchElementException("Nil.head")
def tail: Nothing = throw NoSuchElementException("Nil.tail")
}
def nth[T](n: Int, xs: List[T]): T = {
if (xs.isEmpty) throw IndexOutOfBoundsException
else if (n == 0) xs.head
else nth(n - 1, xs.tail)
}
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