Metalevel building blocks for modular systems

Abstract

The formal definition of any namespace device found in a programming language can be given in terms of transformations on a semantic environment. It is worthwhile, therefore, to consider the implications of incorporating environments as bona fide data objects in a programming system. In this article, we propose a treatment of environments and the mechanism by which they are reified and manipulated, that addresses these concerns. The language described below (Rascal) permits environments to be reified into data structures, and data structures to be reflected into environments, but gives users great flexibility to constrain the extent and scope of these processes. We argue that the techniques and operators developed define a cohesive basis for building large-scale modular systems using reflective programming techniques.