语法分析阶段的主要任务是组词成句。每一种语言都有一组文法。按照这些文法，可以由单词组成语法单位，如短语、语句、过程和程序。语法分析就是通过语法分解，确定整个输入串能否构成语法上正确的句子和程序等。-The main task of the parsing stage is a group of words into a sentence. Each language has a set of grammar. These grammars can be composed by the word grammar units, such as phrases, statements, processes, and procedures. Parsing syntax decomposition, to determine whether the entire input string can form grammatically correct sentences and procedures.