改进的上下文无关文法及其语法分析

Advantaged context-free grammar and it's parsing

针对一些语言的实际应用情况,对标准的上下文无关文法作了改进,将标准的上下文无关文法定义中的非终结符集合和终结符集合进行细化,使得单词推导和句子推导可以使用同一个过程,即词法分析和语法分析可以在同一个语法分析过程完成。还给出了改进后文法的分析算法及算法的时间复杂度分析,证明用这种改进的方法进行语言文法定义更直观、简洁,其分析算法的时间复杂度优于标准上下文无关文法的分析算法。

This paper improves the standard context-free grammar deal with some program language, and made analyze in greater detail to unterminal sign set and terminal sign set, so that the word deduce and the sentence deduce can be made in the same procedure,it means that we can make the lexical analysis and the syntax analysis in the same parsing program, the paper also gives an analysing algorithm, and complexity for the algorithm, thus proves this improving is corect and effective.