Scala Language Streams Infinite self-referent stream
Example
// Generate stream that references itself in its evaluation
lazy val primes: Stream[Int] =
2 #:: Stream.from(3, 2)
.filter { i => primes.takeWhile(p => p * p <= i).forall(i % _ != 0) }
.takeWhile(_ > 0) // prevent overflowing
// Get list of 10 primes
assert(primes.take(10).toList == List(2, 3, 5, 7, 11, 13, 17, 19, 23, 29))
// Previously calculated values were memoized, as shown by toString
assert(primes.toString == "Stream(2, 3, 5, 7, 11, 13, 17, 19, 23, 29, ?)")
