Title: Assisting the Design of XML Schema: Diagnosing Nondeterministic Content Models

Speaker: Prof. Haiming Chen (陈海明研究员)

Time: 3:00pm, May 12th (Thursday), 2011.

Place: Lecture Room, Level 3, Building No. 5, State Key Laboratory of Computer Science, ISCAS

Abstract:

One difficulty in the design of XML Schema is the restriction that the content models should be deterministic, i. e., the unique particle attribution (UPA) constraint, which means that the content models are deterministic regular expressions. This determinism is defined semantically without known syntactic  definition for it, thus making it difficult for users to design. Presently however, no work can provide diagnostic information if content models are nondeterministic, although this will be of great help for designers to understand and modify nondeterministic ones. In this talk we present algorithms that check if a regular expression is deterministic and provide diagnostic information if the expression is not deterministic. With the information provided by the algorithms, designers will be clearer about why an expression is not deterministic. Thus it contributes to reducing the difficulty of designing XML Schema. In particular we outline our new advances and in progress work on this topic. We also introduce a preliminary prototype tool named REAL demonstrating techniques which may be used to assist writing deterministic expressions in designing XML Schema and so on. Joint work with Ping Lu.