gistfile1.txt

require 'pp'

def fib(n) n < 2 ? n : fib(n-1)+fib(n-2); end # Lousy Fibonacci calculator <- heavy job

input  = (0 .. 10).to_enum

enums   = [input]
threads = []
mutex   = Mutex.new

10.times do |i|
  thread = Thread.new(enums[i]) do |input|
    mutex.synchronize do
      enums[i + 1] = Enumerator.new do |yielder|
        input.each { |e| yielder << (e + 1); fib(30) }
      end.lazy
    end
  end
end

enums.last.each { |e| p e }