Appendix C: Regular Expression Primer

Overview

In This Appendix

• Regular expression syntax and tutorial

• The XMLSPY Regular Expression Builder

• Regular expression examples

The XML Schema specificationincludes a pattern-matching mechanism for placing additional restrictions on the permissible value space of XML Schema elements of type xsd:string. Regular expressions are a concise and flexible way to enforce virtually any string pattern, and their use within an XML Schema can save considerable time in writing custom validation modules. This appendix contains a tutorial explaining regular expression syntax, as well as how to use the XMLSPY Regular Expression Builder. Finally, a cheat sheet is included, containing regular expression syntax examples for various commonly encountered data patterns.