While the availability of commercial systems from several vendors indicates maturity in object database management technology, there are numerous issues which remain. This panel will attempt to expose and discuss several of these issues.

Part of the ...

Queries in object-oriented databases can return non-homogeneous sets of objects when no type restrictions are placed on the inputs to the query. The tradition has been to force homogeneity on the result by restricting the types of the inputs. This ...

Programmers informally reason about object-oriented programs by using subtype relationships to classify the behavior of objects of different types and by letting supertypes stand for all their subtypes. We describe formal specification and verification ...

Behavioral compositions, groups of interdependent objects cooperating to accomplish tasks, are an important feature of object-oriented systems. This paper introduces Contracts, a new technique for specifying behavioral compositions and the obligations ...

This paper shows that inheritance and subtyping can be introduced advantageously into a parallel object-oriented language, POOL-I. These concepts are clearly distinguished, because they deal with different aspects of programming. In this way several ...

Genericity allows the substitution of types in a class. This is usually obtained through parameterized classes, although they are inflexible since any class can be inherited but is not in itself parameterized. We suggest a new genericity mechanism, type ...

This paper is concerned with the relation between subtyping and subclassing and their influence on programming language design. Traditionally subclassing as introduced by Simula has also been used for defining a hierarchical type system. The type system ...

A new theory of concurrent objects is presented. The theory has the important advantage of being based directly on a logic called rewriting logic in which concurrent object-oriented computation exactly corresponds to logical deduction. This deduction is ...

Kaleidoscope is an object-oriented language being designed to integrate the traditional imperative object-oriented paradigm with the less traditional declarative constraint paradigm. Imperative state changes provide sequencing while declarative ...

Saraswat recently introduced the framework of concurrent constraint programming [14]. The essence of the framework is that computations consist of concurrent agents interacting by communicating constraints. Several concurrent constraint programming ...

We introduce a novel concurrent logic programming language, which we call LO, based on an extension of Horn logic. This language enhances the process view of objects implementable in Horn-based concurrent logic programming languages with powerful ...