ANTLR中的解析器规则和词法分析器规则之间的实际区别? [英] Practical difference between parser rules and lexer rules in ANTLR?

问题描述

我了解理论上将解析器规则和词法分析器规则分开的理论，但是ANTLR中这两个语句之间的实际区别是什么:

I understand the theory behind separating parser rules and lexer rules in theory, but what are the practical differences between these two statements in ANTLR:

my_rule: ... ;

MY_RULE: ... ;

它们是否导致不同的AST树?不同的表现?潜在的歧义?

Do they result in different AST trees? Different performance? Potential ambiguities?

推荐答案

Jen撰写:

...这两个语句在ANTLR中有什么实际区别...

... what are the practical differences between these two statements in ANTLR ...

MY_RULE将用于标记输入源.它代表了您语言的基本组成部分.

MY_RULE will be used to tokenize your input source. It represents a fundamental building block of your language.

my_rule是从解析器中调用的，它由零个或多个其他解析器规则或词法分析器生成的标记组成.

my_rule is called from the parser, it consists of zero or more other parser rules or tokens produced by the lexer.

那是不同的.

Jen撰写:

它们是否导致不同的AST树?不同的表现? ...

Do they result in different AST trees? Different performance? ...

解析器使用词法分析器生成的令牌来构建AST，因此这些问题对我而言毫无意义.词法分析器仅向解析器馈送"一维令牌流.

The parser builds the AST using tokens produced by the lexer, so the questions make no sense (to me). A lexer merely "feeds" the parser a 1 dimensional stream of tokens.

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