A Graph - Based Speci cation Language forObject - Oriented

Object-oriented programs often have a regular structure where methods are propagated to classes following the part-of and is-a relationships between classes. To abbreviate the description of programs we propose a graph-based propagation notation, called propagation patterns. In addition, we suggest a method for programming with propagation patterns. A propagation pattern consists of an interface speciication of a method, and a set of classes. Together, these two elements induce a larger set of classes to which the speciied interface gets propagated in the form of methods that follow the structure of the underlying class hierarchy. The induced set of classes can be tailored to the speciic needs of the problem at hand and the generated methods can be overridden to customize their implementation.