Integrating XPath with the Functional-Logic Language Toy

摘要

This paper presents a programming framework for incorporating XPath queries into the functional-logic language TOy. The proposal exploits the language characteristics, including non-determinism, logic variables, and higher-order functions and patterns. Our setting covers a wide range of standard XPath axes and tests. In particular reverse axes are implemented thanks to the double nature of XPath queries, which are both higher-order functions and data terms in our setting. The combination of these two different worlds, the functional-logic paradigm and the XML query language XPath, is very enriching for both of them. From the point of view of functional-logic programming, the language is now able to deal with XML documents in a very simple way. From the point of view of XPath, our approach presents several nice properties as the generation of XML test-cases for XPath queries, which can be useful for finding bugs in erroneous queries.