MDMI_ — Handling purely syntactic fields

The current specification does not adequately deal with Semantic Elements that are represented by a multi-field, complex datatype. While the current specification, in theory, could be used to provide a complete MessageSyntaxModel, the location and format languages would have to be unduly complex and non-standard. The MDMI specification should be enriched so that the components of a complex datatype, which are, by definition, purely syntactic, can be mapped.

A modeled MDMI complex datatype is composed of classes, where the classes themselves can be complex datatypes or a class with a single valued simple datatype. Ultimately, all complex datatypes resolve to a set of simple datatypes that correspond to fields (or subfields) in a message format. Therefore, to accommodate Semantic Elements that are complex datatypes, a "fieldname" attribute will be added to the Node abstract class, which holds the name of the simple datatype class. For computational efficiency, a derived Boolean attribute is also added that says this node contains a syntactic element that is part of a complex datatype.