streams

prime-stream.scala

lazy val primes: Stream[Int] =
  2 #:: Stream.from(3).filter(n => primes.takeWhile(p => p * p <= n).forall(p => n % p > 0))

lazy val fib: Stream[BigInt] = 0 #:: 1 #:: fib.zip(fib.tail).map { case(x,y) => x + y }