忽略yacc/lex中的错误 [英] Ignoring errors in yacc/lex

问题描述

我是yacc/lex的新手，我正在研究由其他人编写的解析器.我注意到，当找到未定义的标记时，解析器将返回错误并停止.有没有一种简单的方法可以让它完全忽略它无法解析的行，而直接移到下一行?

I'm new to yacc/lex and I'm working on a parser that was written by someone else. I notice that when an undefined token is found, the parser returns an error and stops. Is there a simple way to just make it ignore completely lines that it cannot parse and just move on to the next one?

推荐答案

只需添加一个类似于

. {
  // do nothing
}

位于所有规则的底部，它只会忽略碰到的所有不符合先前任何规则的东西.

at the bottom of all of your rules, and it will just ignore everything it comes across that doesn't fit any of the previous rules.

如果您有多个状态，则可以在任何状态下工作的包罗万象:

if you have multiple states, then a catch-all that works in any state would then look like:

<*>. {

}

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