词法分析器生成器的设计与实现

Lexical Analysis Generator Design and Realization

当构造词法分析器时,根据单词的正规式定义首先构造与正规式等价的NFA,之后用子集法将NFA转换成DFA,并用此DFA进行词法分析。对词法分析器生成器的设计算法进行了研究,即构造等价于给定正规式非确定有限自动机,并用一种高级语言(C语言)在计算机上实现。

To construct Lexieal analysis, the NFA （Nondeterministie Finite Automata） equivalent to the regular expression should be constructed firstly according to the regular expression definition of words. Then the DFA（ deterministic finite - state automata） used to do the Lexical analysis was acquired with subset method. The algorithm for designing the Lexical analysis generator was introduced, i. e. constructing the NFA equivalent to a given regular expression, furthermore, this algorithm was realized by computer programming of an advanced language（ C language）.