2sp Online Sessions through Java Servlets

This paper presents a new, coprocess-based service for servlet-enabled web servers that allows for establishing online client sessions with an interactive program on the server computer. This service, implemented by an HTTP Java servlet, is designed for experimenting online with prototypical implementations of the interactive program. It provides an enhanced support for research interactions via the WWW by allowing clients to rapidly try, evaluate, and test the program without installing it locally. It is focussed on a speciic implementation of this service for creating Two-Stage Programming (2sp) online sessions. 2sp is a new, mixed-paradigm experimental coordination language for producing both reliable and eecient programs. The current prototypical implementation of 2sp is an interpreter running under SML of New Jersey (SML'97). The coprocess-based service enables time-eecient, easy-to-use, online 2sp sessions for experimenting with 2sp. In addition, it demonstrates how functional programs can be interactively presented on the Web.