search

# File lib/irb/slex.rb, line 103
      def search(chrs, opt = nil)
        return self if chrs.empty?
        ch = chrs.shift
        if node = @Tree[ch]
          node.search(chrs, opt)
        else
          if opt
            chrs.unshift ch
            self.create_subnode(chrs)
          else
            SLex.fail ErrNodeNothing
          end
        end
      end