thread_branch

# File lib/net/imap.rb, line 3048
      def thread_branch(token)
        rootmember = nil
        lastmember = nil

        while true
          shift_token    # ignore first T_LPAR
          token = lookahead

          case token.symbol
          when T_NUMBER
            # new member
            newmember = ThreadMember.new(number, [])
            if rootmember.nil?
              rootmember = newmember
            else
              lastmember.children << newmember
            end
            lastmember = newmember
          when T_SPACE
            # do nothing
          when T_LPAR
            if rootmember.nil?
              # dummy member
              lastmember = rootmember = ThreadMember.new(nil, [])
            end

            lastmember.children << thread_branch(token)
          when T_RPAR
            break
          end
        end

        return rootmember
      end