Simplify the Design of XML Schemas by Type Dependencies

In XML Schema, the type definition mechanism is responsible for defining types as well as passing contextual information, which may cause some design problems such as artificial types. This paper proposes a new kind of XML schema called Type Dependencies (TD) schema to realize the separation of those two tasks. A TD schema includes two parts, a set of type dependencies which is responsible for passing contextual information and a complete competition grammar which is only responsible for defining types. It can help users to design better schemas more easily, since there are no problems related to Element Declarations Consistent (EDC) rule and artificial types in TD schemas. Furthermore, the expressiveness of TD schemas is more powerful than XML Schema and it also satisfies the semantic concept of 1-pass preorder typing, which make it more suitable for streaming data.