Streams

main (streams, print)

main()
    xs = [int: 1, 2, 3, 4, 5, 6]
    # stream(xs) borrows the list and yields its elements.
    evens = streams.filter(stream(xs), (x &int: x % 2 == 0))
    squares = streams.map(evens, (x &int: x * x))
    total = streams.sum(squares, 0)
    # A pipeline builds no intermediate list; collect when you want one.
    firstThree = streams.collect(streams.take(streams.range(1, 100), 3), [int:])
    print.line("{total} {len(firstThree)}")

56 3