select_with_index

gistfile1.rb

module Enumerable
   def select_with_index
      i = 0
      self.select { |e|
        i += 1
        yield e, i
      }
   end
end

ary = *(?a..?z)
len = ary.length

ary.select_with_index { |e, i| puts e if i == len / 2 }