A module system for scheme

Abstract

This paper presents a module system designed for largescale programming in Scheme. The module system separates specifications of objects from their implementations, permitting the separate development, compilation, and testing of modules. The module system also includes a robust macro facility.We discuss our design goals, the design of the module system, implementation issues, and our future plans.

First-class macros have types

“…As I remarked before, templates strongly resemble the interfaces found in other module systems [Mac84,CR90,Ree93], but without any name hiding mechanism. In this section we will use templates and their instances to represent the interfaces and modules in a fully functional module system.…”

“…A template is a bit like the "interfaces" found in some module systems [Mac84,CR90,Ree93], but without any name hiding mechanisms.…”

Extending the scope of syntactic abstraction

“…Our system is similar in some respects to systems described by Curtis and Rauen [2] and Rees [16]. Our system is based on simpler core module constructs, however, and derives its expressive power largely via syntactic abstraction.…”

“…Over the past several years there has been increasing interest in combining lexitally scoped macros and modules [2,16,171. Building on this work we present here the first fully implemented system that allows arbitrary composition of module and macro facilities, supports separate compilation, and supports fully general macro transformations while maintaining lexical scoping for all macros.…”

Modular object-oriented programming with units and mixins

“…Programmers can regard top-level expressions as "modules" that hide private definitions by using let or letrec. A number of Scheme systems have been developed that codify the module-via-top-level idea [8,10,36,35,44], but none of these satisfies the criteria in Section 5. In contrast, Kelsey's proposed module system [22] captures many of the same ideas as units.…”