module Mail::DateTime

def _nt_primary
  start_index = index
  if node_cache[:primary].has_key?(index)
    cached = node_cache[:primary][index]
    if cached
      cached = SyntaxNode.new(input, index...(index + 1)) if cached == true
      @index = cached.interval.end
    end
    return cached
  end
  i0, s0 = index, []
  i2, s2 = index, []
  r3 = _nt_day_of_week
  s2 << r3
  if r3
    if has_terminal?(",", false, index)
      r4 = instantiate_node(SyntaxNode,input, index...(index + 1))
      @index += 1
    else
      terminal_parse_failure(",")
      r4 = nil
    end
    s2 << r4
  end
  if s2.last
    r2 = instantiate_node(SyntaxNode,input, i2...index, s2)
    r2.extend(Primary0)
  else
    @index = i2
    r2 = nil
  end
  if r2
    r1 = r2
  else
    r1 = instantiate_node(SyntaxNode,input, index...index)
  end
  s0 << r1
  if r1
    r5 = _nt_date
    s0 << r5
    if r5
      r6 = _nt_FWS
      s0 << r6
      if r6
        r7 = _nt_time
        s0 << r7
        if r7
          r9 = _nt_CFWS
          if r9
            r8 = r9
          else
            r8 = instantiate_node(SyntaxNode,input, index...index)
          end
          s0 << r8
        end
      end
    end
  end
  if s0.last
    r0 = instantiate_node(SyntaxNode,input, i0...index, s0)
    r0.extend(Primary1)
  else
    @index = i0
    r0 = nil
  end
  node_cache[:primary][start_index] = r0
  r0
end

def root
  @root ||= :primary
end