Using Prolog for Transforming XML Documents Rene´ Haberland Technical University of Dresden, Free State of Saxony, Germany Saint Petersburg State University, Saint Petersburg, Russia email:
[email protected] (translation into English from 2007) Abstract—Proponents of the programming language Prolog all or with severe restrictions into hosting languages, like Java, share the opinion Prolog is more appropriate for transforming C++ or Pascal. XML documents than other well-established techniques and In order to resolve this problem, two strategies can be languages like XSLT. This work proposes a tuProlog-styled interpreter for parsing XML documents into Prolog-internal identified as most promising. First, integrate new features. The lists and vice versa for serialising lists into XML documents. language gets extended. However, this can only succeed if lingual concepts are universal enough w.r.t. lexemes, idioms. Based on this implementation, a comparison between XSLT Second, choose a federated approach. Depending on the imple- and Prolog follows. First, criteria are researched, such as con- mentation, the hosting language is simulated by introspection. sidered language features of XSLT, usability and expressibility. These criteria are validated. Second, it is assessed when Prolog Solely concepts remain untouched. distinguishes between input and output parameters towards The reasons against the first approach are a massive rise in reversible transformation. complexity and a notoriously incompatible paradigm. Hence, the federated approach is chosen to implement the transfor- I. INTRODUCTION mation language with Prolog being visible to the user. A. Preliminaries A transformation within XML is a mapping from XML onto B. Motivation XML. W.l.o.g. only XML as output is considered in this work.