Regular Expression Pattern

Regular Expression Pattern Matching - A Simpler Design

159-2011: Perl Regular Expression in SAS® Macro Programming

In this paper, the Perl regular expression facility that provides a concise and flexible means for matching strings of text is extended to the macro environment using three new macro functions. Consequently, this allows direct pattern matching and replacement in macro variables, facilitating the construction of flexible and customized functions through internally parsing patterned inputs. This ...

Generation of Pattern - Matching Algorithms by Extended Regular Expressions

It is dicult to express the denition of the comments of C language in a regular expression. However, the denition can be expressed by a simple regular expression by introducing a special symbol, called the any-symbol, that represents any single character, or by introducing a kind of negation symbol into regular expressions. In general, the problem of string pattern matching can be expressed as ...

An Improved Prefix-Free Regular-Expression Matching

We revisit the regular-expression matching problem with respect to prefix-freeness of the pattern. It is known that a prefix-free pattern gives only a linear number of matching substrings in the size of an input text. We improve the previous algorithm and suggest an efficient algorithm that finds all pairs (start, end) of start and end positions of all matching substrings with a single scan of ...

Probabilistic Pattern Matching and the Evolutionof Stochastic Regular

The use of genetic programming for probabilistic pattern matching is investigated. A stochastic regular expression language is used. The language features a statistically sound semantics, as well as a syntax that promotes eecient manipulation by genetic programming operators. An algorithm for eecient string recognition based on approaches in conventional regular language recognition is used. Wh...

Prefix-free regular languages and pattern matching

We explore the regular-expression matching problem with respect to prefix-freeness of the pattern. We prove that a prefix-free regular expression gives only a linear number of matching substrings in the size of a given text. Based on this observation, we propose an efficient algorithm for the prefix-free regular-expression matching problem. Furthermore, we suggest an algorithm to determine whet...