code: def p_portlist_io(self, p):
          'portlist : LPAREN ioports RPAREN SEMICOLON'
          p[0] = Portlist(ports=p[2], lineno=p.lineno(1))
          p.set_lineno(0, p.lineno(1)f p_portlist_io(self, p):
          'portlist : LPAREN ioports RPAREN SEMICOLON'
          p[0] = Portlist(ports=p[2], lineno=p.lineno(1))
          p.set_lineno(0, p.lineno(1))
docs: portlist : LPAREN ioports RPAREN SEMICOLON