def p_qreg_decl(self, program):
        """
           qreg_decl : QREG indexed_id
        """
        program[0] = node.Qreg([program[2]])
        if program[2].name in self.external_functions:
            raise QasmError("QREG names cannot be reserved words. "
                            + "Received '" + program[2].name + "'")
        if program[2].index == 0:
            raise QasmError("QREG size must be positive")
        self.update_symtab(program[0])
qreg_decl : QREG indexed_id