Scala Language Streams Using a Stream to Generate a Random Sequence
Example
genRandom creates a stream of random numbers that has a one in four chance of terminating each time it's called.
def genRandom: Stream[String] = {
val random = scala.util.Random.nextFloat()
println(s"Random value is: $random")
if (random < 0.25) {
Stream.empty[String]
} else {
("%.3f : A random number" format random) #:: genRandom
}
}
lazy val randos = genRandom // getRandom is lazily evaluated as randos is iterated through
for {
x <- randos
} println(x) // The number of times this prints is effectively randomized.
Note the #:: construct, which lazily recurses: because it is prepending the current random number to a stream, it does not evaluate the remainder of the stream until it is iterated through.
