词法分析器的命名约定是什么？
function yy_r9_1($yy_subpatterns)
{
$this->token = Smarty_Internal_Templateparser::TP_PHP_CODE;
$this->yypopstate();
}
以上来自PHP中smarty的词法分析器，有人知道yy_r9_1是什么意思吗？
function yy_r9_1($yy_subpatterns)
{
$this->token = Smarty_Internal_Templateparser::TP_PHP_CODE;
$this->yypopstate();
}
The above is from the lexer of smarty in PHP,anyone knows what yy_r9_1 means?
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yy是YACC的前缀，以避免冲突。回到 YACC 构建的时代，没有命名空间或类，甚至没有结构。实际上YACC最初是用B编写的，C的前身。r9可能代表规则号9，1可能是需要处理多个函数的规则的增量前缀。然而，即使我错了并且这些字符串有其他含义，我怀疑您是否可以利用这些信息。这需要深入理解词法分析器和解析器的内部结构以及最后但并非最不重要的语法规则。如果您理解语法，您也可以更改它并重新生成词法分析器，而不是使用甚至操作它的子例程。
yyis YACC's prefix to avoid collisions. Back in the days when YACC was built, there were no namespaces or classes, not even structs. Actually YACC was initially written in B, the predecessor of C.r9probably stands for rule number 9 and1may be an incremental prefix for rules that require multiple functions to be processed.However, even if I'm wrong and these strings mean something else, I doubt you can make any use of this information. This would require deep understanding of the internals of the lexer and parser and last but not least of the grammar rules. If you understand the grammar, you could as well change it and re-generate the lexer instead of using or even manipulating it's subroutines.