Towards a Unified Framework for Declarative Structured Communications

We present a unified framework for the declarative analysis of structured communications. By relying on a (timed) concurrent constraint programming language, we show that in addition to the usual operational techniques from process calculi, the analysis of structured communications can elegantly exploit logic-based reasoning techniques. We introduce a declarative interpretation of the language for structured communications proposed by Honda, Vasconcelos, and Kubo. Distinguishing features of our approach are: the possibility of including partial information (constraints) in the session model; the use of explicit time for reasoning about session duration and expiration; a tight correspondence with logic, which formally relates session execution and linear-time temporal logic formulas

Concurrency Annotations and Reusability

Widespread acceptance of concurrent object-oriented programming in the field can only be expected if smooth integration with sequential programming is achieved. This means that a common language base has to be used, where the concurrent syntax differs as little as possible from the sequential one but is associated with a "natural" concurrent semantics that makes library support for concurrency superfluous. In addition, not only should sequential classes be reusable in a concurrent context, but concurrent classes should also be reusable in a sequential context. It is suggested that concurrency annotations be inserted into otherwise sequential code. They are ignored by a sequential compiler, but a compiler for the extended concurrent language will recognize them and generate the appropriate concurrent code. The concurrent version of the language supports active and concurrent objects and favours a declarative approach to synchronization and locking which solves typical concurrency problems in an easier and more readable way than previous approaches. Concurrency annotations are introduced using Eiffel as the sequential base

An Integrated Development Environment for Declarative Multi-Paradigm Programming

In this paper we present CIDER (Curry Integrated Development EnviRonment), an analysis and programming environment for the declarative multi-paradigm language Curry. CIDER is a graphical environment to support the development of Curry programs by providing integrated tools for the analysis and visualization of programs. CIDER is completely implemented in Curry using libraries for GUI programming (based on Tcl/Tk) and meta-programming. An important aspect of our environment is the possible adaptation of the development environment to other declarative source languages (e.g., Prolog or Haskell) and the extensibility w.r.t. new analysis methods. To support the latter feature, the lazy evaluation strategy of the underlying implementation language Curry becomes quite useful.Comment: In A. Kusalik (ed), proceedings of the Eleventh International Workshop on Logic Programming Environments (WLPE'01), December 1, 2001, Paphos, Cyprus. cs.PL/011104