Towards safe and flexible object adaptation

In this paper, a programming language NextEJ is proposed. NextEJ is based on Epsilon model, which realizes object adaptation to contexts. The novelty of Epsilon model is its ability to make objects be able to freely enter or leave contexts dynamically and belong to multiple contexts at a time. However, such kind of flexibility also easily brings type-unsafety. NextEJ tackles this problem by introduc-ing a new feature called context activation scope. Inside a context activation scope, it is assured that an object is al-ways bound with the role activated so that no method-not-understood errors occur at run-time. Furthermore, context activation scope can be nested so that multiple contexts can be activated at a time. A role instance has a pre-defined field thisContext which refers to its enclosing context instance. In the case of multiple context activations, the reference of thisContext is interpreted as a composite context whose behavior is determined by the order of activations

Loosely Connected RPC: An Approach for Extendable Interface of Web Services

To make distributed software systems evolve easily, it is desirable to make connections between services and clients loose. The recent success of Web based technologies may be attributed to the core characteristic, i.e. being more loosely connected than the traditional RPC technologies such as CORBA, DCOM and Java RMI. Web services are distributed systems built on the Web based technologies; however, in many cases the programming model used in Web services is similar with the traditional RPC that leads to tight connections between services and clients. For example, in many cases the return value must have the exact type that the client expects. To tackle this problem, we propose an approach for extendable interface of remote objects. For this purpose, we apply XML pattern matching to a SOAP message to extract data it conveys. Because XML pattern matching is applied only to a fragment of information provided by a SOAP message and does not require the whole information of objects it conveys, the client programs equipped with XML pattern matching still work correctly even when the service evolves

Embedding XML Processing Toolkit on General Purpose Programming Language

Many methods for XML processing have been proposed in the last few years. One popular approach is to process XML documents by using existing programming languages. Another popular approach is to create a new programming language specialized to the domain of XML processing. We propose a new approach of constructing XML processors: embedding XML processing language on Lisp. Owing to this approach, we may seamlessly invoke the functions of XML-specific language from Lisp