In [13] we defined the λ&-calculus, a simple extension of the typed λcalculus to model typed object-oriented languages. This paper is the continuation or, rather, the companion of [13] since it analyzes the practical counterpart of the theoretical issues introduced there. Indeed, to develop a formal study of type systems for object-oriented languages we define a meta-language based on λ& and we...

Two object-oriented programming language paradigms— dynamic, prototype-based languages and multi-method languages— provide orthogonal benefits to software engineers. These two paradigms appear to be in conflict, however, preventing engineers from realizing the benefits of both technologies in one system. This paper introduces a novel object model, prototypes with multiple dispatch (PMD), which ...

Common to many high-level, declarative and object oriented languages are the use of dynamic dispatch and garbage collection. Dynamic dispatch is the mechanism by which the selection of a method to run, based on both its signature, and the type of one or more of its arguments, is made. A garbage collector is responsible for efficient ‘recycling’ of memory that is no longer needed, termed ‘garbag...

We have implemented a new method for eliminating reference parameter aliases. This method allows procedure calls with overlapping call-by-reference parameters, but at the same time guarantees that procedure bodies are alias-free. The method involves writing multiple bodies for a procedure: one per aliasing combination. Calls are automatically dispatched to the appropriate procedure body based o...

Goals of flexibility and re-usability in typed object-oriented languages suggest the requirement of double dispatch, i.e., the mechanism of dynamically selecting a method not only according to the run-time type of the receiver (single dispatch), but also to the run-time type of the argument. However, many mainstream languages, such as, e.g., C++ and Java, do not provide it, resorting to only si...

Original scientific paper Economic Load Dispatch problem has been previously solved successfully with swarm techniques. However, power systems with complex behaviours still await a robust algorithm to be developed for their optimization more precisely. Economic Dispatch problem with constraints such as generator limits, total power demand, ramp rate limits and prohibited operating zones, makes ...

The factory is a complex dynamic environment and scheduling operations for such an environment is a challenging problem. In practice, dispatch scheduling policies are commonly employed, as they offer an efficient and robust solution. However, dispatch scheduling policies are generally myopic, and as such they are susceptible to sub-optimal decision-making. In this paper, we attempt to improve u...