Composition Languages for Black-Box Components

Supporting reuse of existing pieces of code is one of the main goals of software engineering. In the name of reuse, module-based programming languages came to be, only to be surpassed by object-oriented technology. With the same motivation component-based solutions are overtaking object-oriented solutions. However, the delegation-only focus of component-based programming risks of resulting in the same problems that modular-based approaches ran into. To counter this, we claim that one of th e important problems that should be addressed by component languages is the composition of components. More specifically, we see component languages where components are black-box abstractions, and with (one or more) composition languages to glue them tog ether. As an example we show a functional (Piccola) and a logic (QSoul) composition approach.