An Application Framework for Compositional Modularity

This dissertation presents a framework for the application of compositional modularity a module model that facilitates extensive reuse of highly decomposed software Compositional modularity supports not only the traditional notions of program decomposition and encapsulation but also e ective mechanisms for module recom position Based on a previously developed model a suite of operators individually achieve e ects of adaptation and combination on a simple notion of modules viewed as self referential namespaces This dissertation extends the previous model by introducing the notion of hierarchical nesting as a composition operation Fur thermore this work shows that compositional modularity is unifying in scope Important e ects and idioms of advanced modularity including several varieties of inheritance in object oriented programming nd convenient expression within this model Compositional modularity can be applied within a wide range of systems that manipulate self referential namespaces To demonstrate four distinctively di ering systems based on the model are presented an interpreter for a module extension to the programming language Scheme a programmable linker for composing compiled object les a compiler front end for a compositional interface de nition language and a compositional document processing system It is shown that systems such as the above derive important bene ts from incorporating compositional modularity To facilitate the application of compositional modularity the model is itself realized as a generic reusable software architecture an object oriented appli cation framework named Etyma Etyma comprises a collection of interacting classes corresponding to the essential concepts of the model The framework may be reused to e ciently build completions i e tools for compositionally modular systems Three of the four systems mentioned previously were built as direct completions of Etyma and the fourth evolved in parallel with the framework Signi cant design and code reuse was achieved in the construction of these system prototypes as completions of the framework