Coercion as a metaphor for computation

Abstract

Consideration is given to a generalization of coercion that permits structured transformations between program and data structures. The nature of these coercions goes significantly beyond what is found in most modern programming languages. The intent is to develop a programming model that permits the expression of a wide range of superficially diverse modularity constructs within a simple and unified framework. The design of this model is based on the observation that a variety of program structures found in modern programming languages are represented fundamentally in terms of an environment. Given suitable transformations that map the environment representation of a program structure into a data object, it is possible to enable the programmer to gain explicit control over the naming environment. An investigation is made of the semantics of program/data coercion in the presence of a non-strict parallel evaluation semantics for environments. Parallelism and program/data coercion form an interesting symbiosis and it is the investigation of this interaction that forms the primary focus of this work. >