Compilation of Generic Regular Path Expressions Using C++ Class Templates

• Published in: Compiler Construction pp. 27 - 42
• Main Author: Padovani, Luca
• Format: Book Chapter Conference Proceeding
• Language: English
• Published: Berlin, Heidelberg Springer Berlin Heidelberg 2005; Springer
• Series: Lecture Notes in Computer Science
• Subjects: Applied sciences; Computer science; control theory; systems; Denotational Semantic; Exact sciences and technology; Path Expression; Programming languages; Software; Tree Automaton; Walk Method; XPath Expression; Compiler; Coordination language; Compilation; Navigation; Automaton; Regular expression; Distributed system; Backtracking; Data path; Message passing; Programming language; Semantics; Data structure; Data link; Indexing; Hyperlink
• ISBN: 9783540254119; 3540254110
• ISSN: 0302-9743; 1611-3349
• DOI: 10.1007/978-3-540-31985-6_3

Various techniques for the navigation and matching of data structures using path expressions have been the subject of extensive investigations. No matter whether such techniques are based on type information, indexing, automata, it is desirable to synthesize implementations automatically, starting from a high-level description of the path expressions to be traversed. In this paper we present a library of C++ templates for the representation of regular path expressions and their compilation into efficient backtracking algorithms. The resulting code can be used to implement visitors, pattern matchers, node collectors on regular paths over possibly heterogeneous, linked data structures. The point of the paper is on the path compilation technique, which was inspired by a continuation-passing, functional semantics of the path expressions. We rely on some peculiar aspects of C++ templates to create a compilation framework that closely follows the given semantics.