1. A method, comprising: parsing a programmed source file to generate an in-memory graph of a syntactical structure of the source file, wherein the in-memory graph is a syntactic representation of the programmed source file; generating an XML (Extensible Markup Language) document from the syntactic representation of the programmed source file; validating the XML document with an XML schema; searching for a first Extensible Stylesheet Language (XSL) transform, wherein the first XSL transform is designated in the programmed source file as a first module-level attribute, the first module-level attribute being user-defined such that the XML-based preprocessor recognizes the first module-level attribute and a source file compiler does not; applying the first XSL transform to the XML document to generate a modified XML document; validating the modified XML document with the XML schema; searching for a second XSL transform, wherein the second XSL transform is designated in the programmed source file as a second module-level attribute, the second module-level attribute being user-defined such that the XML-based preprocessor recognizes the attribute and the source file compiler does not; and generating an output file from the modified XML document in a format of the programmed source file.