generator example

require 'generator'# Generator from an Enumerable objectg = Generator.new(['A', 'B', 'C', 'Z'])while g.next?  puts g.nextend# Generator from a blockg = Generator.new { |g|  for i in 'A'..'C'    g.yield i  end  g.yield 'Z'}# The same result as abovewhile g.next?  puts g.nextend