The things you listed may form a monad, but your list/iterator transformation doesn't use monadic composition. > list.select { |x| x.foo > 10 }.map { |x| x.ba

The things you listed may form a monad, but your list/iterator transformation doesn't use monadic composition. > list.select { |x| x.foo > 10 }.map { |x| x.bar } Where's `bind` or `join` in that example?