Author Description

This dissertation, "Static Type Analysis of XQuery Expressions Using Rewriting Calculus" by Zhen, Wang, , was obtained from The University of Hong Kong (Pokfulam, Hong Kong) and is being sold pursuant to Creative Commons: Attribution 3.0 Hong Kong License. The content of this dissertation has not been altered in any way. We have altered the formatting in order to facilitate the ease of printing and reading of the dissertation. All rights not granted by the above license are retained by the author.<br> Abstract:<br> Abstract of thesis entitled "Static Type Analysis of XQuery Expressions Using Rewriting Calculus" Submitted by Zhen WANG for the degree of Master of Philosophy at The University of Hong Kong in May 2007 As the the popularity of the Extensible Markup Language (XML) increases as a standard for information storage and exchange on the Web, demand has grown for eective and ecient XML query languages. XQuery, proposed by W3C, hasbeenwidelyacceptedforitscapacitytomakequeriesconciseandeasily understood. Many studies have been dedicated to dierent topics in processing XQuery expressions. Static type analysis has been recognized as an interesting research problem in the last few years, because it allows early detection of errors at compile-time, and generates type information for the intermediate and nal results of a query, which could serve as a basis of query optimization and other query manipulations. In thisthesis, we proposea newapproach to typeXQuery expressionsbased on XML Schema, using a relatively young but powerful calculus, rewriting cal- culus (ρ-calculus). ρ-calculus integrates Term Rewriting and Lambda Calculus uniformly, and also provides exible typing facilities. We adopt the rst-order ρ-calculus with its type system, and extend the type system in order to meet the requirementsforprocessingXMLdatavalues, XMLSchemasandXQueryexpres- sions. We import the type information from XML Schemas into our approach to generate context as one input. The other inp