Unnecessary extra case for takeViaUnfold

[georgms]

The special case for handling n = 1 in the implementation of takeViaUnfold is not necessary:

fpinscala/answerkey/laziness/13.answer.scala

Lines 7 to 12 in 71a7931

	def takeViaUnfold(n: Int): Stream[A] =
	unfold((this,n)) {
	case (Cons(h,t), 1) => Some((h(), (empty, 0)))
	case (Cons(h,t), n) if n > 1 => Some((h(), (t(), n-1)))
	case _ => None
	}

It's already covered by the general case:

case (Cons(h,t), n) if n > 1 => Some((h(), (t(), n-1)))

Test:

test("takeUnfold") {
  assertEquals(Stream(1, 2, 3).takeUnfold(0).toList, List.empty)
  assertEquals(Stream(1, 2, 3).takeUnfold(1).toList, List(1))
  assertEquals(Stream(1, 2, 3).takeUnfold(2).toList, List(1, 2))
  assertEquals(Stream(1, 2, 3).takeUnfold(5).toList, List(1, 2, 3))
}