def copy
      cop = Word.new( self.length )
      index = 0
      while( index < self.length )
        cop.set_char(index , self.get_char(index))
        index = index + 1
      end
      cop
    end
def copy
      cop = Word.new( self.length )
      index = 0
      while( index < self.length )
        cop.set_char(index , self.get_char(index))
        index = index + 1
      end
      cop
    end
initialize with length. For now we try to keep all non-parfait (including String) out
 String will contain spaces for non-zero length
 Risc provides methods to create Parfait objects from ruby
 return a copy of self