match

# File lib/irb/slex.rb, line 167
      def match(chrs, op = "")
        D_DETAIL.print "match>: ", chrs, "op:", op, "\n"
        if chrs.empty?
          if @preproc.nil? || @preproc.call(op, chrs)
            DOUT.printf(D_DETAIL, "op1: %s\n", op)
            @postproc.call(op, chrs)
          else
            nil
          end
        else
          ch = chrs.shift
          if node = @Tree[ch]
            if ret = node.match(chrs, op+ch)
              return ret
            else
              chrs.unshift ch
              if @postproc and @preproc.nil? || @preproc.call(op, chrs)
                DOUT.printf(D_DETAIL, "op2: %s\n", op.inspect)
                ret = @postproc.call(op, chrs)
                return ret
              else
                return nil
              end
            end
          else
            chrs.unshift ch
            if @postproc and @preproc.nil? || @preproc.call(op, chrs)
              DOUT.printf(D_DETAIL, "op3: %s\n", op)
              @postproc.call(op, chrs)
              return ""
            else
              return nil
            end
          end
        end
      end