First-Class Structures for Standard ML

Claudio V. Russo


Standard ML is a statically typed programming language that is suited for the construction of both small and large programs. ``Programming in the small'' is captured by Standard ML's Core language. ``Programming in the large'' is captured by Standard ML's Modules language that provides constructs for organising related Core language definitions into self-contained modules with descriptive interfaces. While the Core is used to express details of algorithms and data structures, Modules is used to express the overall architecture of a software system. The Modules and Core languages are stratified in the sense that modules may not be manipulated as ordinary values of the Core. This is a limitation, since it means that the architecture of a program cannot be reconfigured according to run-time demands. We propose a novel extension of the language that allows modules to be manipulated as first-class values of the Core language. The extension greatly extends the expressive power of the language, and has been shown to be compatible with both Core type inference and a separate extension to higher-order modules.

An earlier version of a paper submitted to 2000 International Conference on Principles of Programming Languages.

This is a 21-page article. It is available in the following forms.