XML and Multilingual Document Authoring: Convergent Trends

XML and Multilingual Document Authoring: Convergent Trends Marc Dymetman Veronika Lux Xerox Research Centre Europe 6, chemin de Maupertuis 38240 Meylan, France {dymetman,lux}@xrce.xerox.com Aarne Ranta Department of Computing Science Chalmers University of Technology and Göteborg University S-412 96 Göteborg, Sweden aarne@cs.chalmers.se Abstract Typical approaches to XML authoring view a XML doc- ument as a mixture of structure (the tags) and surface (text between the tags). We advocate a radical approach where the surface disappears from the XML document altogether to be handled exclusively by rendering mech- anisms. This move is based on the view that the author’s choices when authoring XML documents are best seen as language-neutral semantic decisions, that the struc- ture can then be viewed as interlingual content, and that the textual output should be derived from this content by language-specific realization mechanisms, thus assimi- lating XML authoringto MultilingualDocument Author- ing. However, standard XML tools have important limi- tations when used for such a purpose: (1) they are weak at propagating semantic dependencies between different parts of the structure, and, (2) current XML rendering tools are ill-suited for handling the grammatical combi- nation of textual units. We present two related proposals for overcoming these limitations: one (GF) originating in the tradition of mathematical proof editors and con- structive type theory, the other (IG), a specialization of Definite Clause Grammars strongly inspired by GF. 1 Introduction The typical approach to XML authoring views an XML document as a mixture of tree-like structure, expressed through balanced labelled parentheses (the tags), and of surface, expressed through free text interspersed be- tween the tags (PCDATA). A Document Type Defini- tion (DTD) is roughly similar to a context-free gram- mar1 with exactly one predefined terminal. It defines a set of well-formed structures, that is, a language over trees, where each nonterminal node can dominate either the empty string, or a sequence of occurrences of nonter- minal nodes and of the terminal node pcdata. The ter- minal pcdata has a special status: it can in turn dominate any character string (subject to certain restrictions on the characters allowed). Authoring is typically seen as a top- down interactive process of step-wise refinement of the root nonterminal (corresponding to the whole document) where the author iteratively chooses a rule for expanding 1But see (Prescod, 1998) for an interesting discussion of the differ- ences. a nonterminal already present in the tree,2 and where in addition the author can choose an arbitrary sequence of characters (roughly) for expanding the pcdata node. One can observe the following trends in the XML world: � A move towards more typing of the surface: Schemas (W3C, 1999a), which are an influential proposal for the replacement of DTD’s, provide for types such as float, boolean, uri, etc., instead of the single type pcdata; � A move, already constitutive of the main purpose of XML as opposed to HTML for instance, towards clearer separation between content and form, where the original XML document is responsible for con- tent, and powerful styling mechanisms (e.g. XSLT …

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