Variations on an Invisible Theme

Abstract

InvisibleXML (iXML) is designed as a lightweight context-free grammar notation to describe a mapping between structured textual data and an XML representation of that structure. As such it is being used practically and several implementations of processors exist, for various execution environments. But one of the perhaps underexploited features of iXML is that an iXML grammar text can itself be parsed by the iXML grammar definition to produce an equivalent XML representation of that grammar (i.e. as a series of production rules). With the power of XSLT to analyse, modify and generate such an XML representation, there are a number of interesting possibilities for expanding the scope of Invisible XML by so doing. This paper describes some of the types of manipulation that can be achieved, giving examples ranging from multi-language support to tree-depth reduction, automated generation of a parser for XPath/XQuery and “round-tripping” via generated XSLT transforms, and outlines some of the practical problems encountered.