期刊名称：International Journal of Computer Trends and Technology
电子版ISSN：2231-2803
出版年度：2013
卷号：4
期号：9-2
页码：3151-3156 September Issue 2013 .ISSN 2231
出版社：Seventh Sense Research Group
摘要：A Regular expression is a sequence of text characters, some of which are understood to be meta characters with symbolic meaning, and some of which have their literal meaning, that together can automatically identify textual material of a given pattern, or process a number of instances of it that can vary from a precise equality to a very general similarity of the pattern. The pattern sequence itself is an expression that is a statement in a language designed specifically to represent prescribed targets in the most concise and flexible way to direct the automation of text processing of general text files, specific textual forms, or of random input strings .Regular expressions (RE) are getting popular still under developed stage of their inherent complexity that limits the total number of RE that can be known by using a single chip. This limit on the number of RE doesn’t pair with the scalability of present RE detection systems. Existing schemes is limited in the old detection paradigm based on per characterstate working and also state transition detection. Keeps concentrate on optimizing the count of states and the need transitions, but not on concept of optimizing the suboptimal characterbased detection method .The advantages of allowing outofsequence detection, rather than detecting components of a RE in order of appearance, have not been explored. LaFA needs less memory due to these three aspects providing specialized and optimized detection modules, systematically reordering the RE detection sequence and sharing states among automata for different RE’s
关键词：Finite States Optimization on Look-Ahead Deterministic Finite Automation
