Designing for change

Abstract

Invisible XML (ixml) is a method for treating non-XML documents as if they were XML. The 1.0 specification for Invisible XML was announced in June of this year. No technology foresees all of its use cases, especially in 1.0. How can ixml allow experimentation, and channel experimentation in useful ways, to allow ideas to be expressed in ixml grammars that go beyond what is foreseen, without compromising interoperability or the value of strict conformance to the specification? Many programming languages (C, JavaScript, Pascal, XQuery, etc.) address this question with pragmas. A pragma is a semi-formal way to instruct a processor/compiler/interpreter how it should operate. Typical pragmas extend a specification but are not a part of it. We propose pragmas as an optional add-on to ixml to allow implementation of non-standardized functionality in a way that does not interfere with standard ixml processing. We describe our general framework for pragmas, some specific pragmas (to illustrate how pragmas can be used), and a few pragmatic implementations.