Generic Programming by Program Composition (position Paper)

Recently, generic programming becomes of a major interest in several programming paradigms. A recurrent idea to achieve genericity is to abstract computations from their representative data structures. This allows these generic speciications to be instantiated onto a large number of neighboring data structures. Moreover the program can be adapted when the data structures have to evolve. Polytypic programming, adaptive programming and generic attribute grammars are generic programming methods related to this approach. Their comparison leads us to propose a common framework for generic programming: automatic generation of programs that compute morphisms between data structures, and program composition. Thanks to this compositional approach, the complete specialization of generic programs could be advantageously delegated to some powerful and general deforestation method.