is_even = where(lambda x: x % 2 == 0) sum(fib() | is_even | take_while(lambda x: x < 4000000)
[1] https://github.com/JulienPalard/Pipe
Like maybe bitshifting strings into streams wasn't the right syntax, Bjarne
[1] https://github.com/JulienPalard/Pipe