Scl: A Simple, Uniform and Operational Language for Component-Oriented Programming in Smalltalk

Unanticipated connection of independently developed components is one of the key issues in component-oriented programming. While a variety of component-oriented languages have been proposed, none of them has achieved a breakthrough yet. In this paper, we present Scl a simple language dedicated to component-oriented programming. Scl integrates well-known features such as component class, component, interface, port or service. All these well-known features are presented, discussed and compared to existing approaches because they vary quite widely from one language to another. But, these features are not enough to build a component language. Indeed, most approaches use language primitives and shared interfaces to connect components. But shared interfaces are in contradiction with the philosophy of independently developed components. To this issue, Scl provides new features such as a uniform component composition model based on connectors. Connectors represent interactions between independently developed components. Scl also integrates component properties which enable connections based on component state changes with no requirements of specific code in components.