Standard ML includes a set of module constructs that support programming in the large. These constructs extend ML's basic polymorphic type system by introducing the dependent types of Martin Lo"f's Intuitionistic Type Theory. This paper discusses the problems involved in implementing Standard ML's modules and describes a practical, efficient solution to these problems. The representations and algorithms of this implementation were inspired by a detailed formal semantics of Standard ML developed by Milner, Tofte, and Harper. The implementation is part of a new Standard ML compiler that is written in Standard ML using the module system. March 11, An Implementation of Standard ML Modules David MacQueen AT&T Bell Laboratories Murray Hill, NJ 07974 1. Introduction An important part of the revision of ML that led to the Standard ML language was the inclusion of module facilities for the support of "programming in the large." The design of these facilities went through several versions [...

Standard ML includes a set of module constructs that support programming in the large. These constructs extend ML's basic polymorphic type system by introducing the dependent types of Martin L/Sf's Intuitionistic Type Theory. This paper discusses the problems involved in implementing Standard ML's modules and describes a practical, efficient solution to these problems. The representations and algorithms of this implementation were inspired by a detailed formal semantics of Standard ML developed by Milner, Tofte, and Harper. The implementation is part of a new Standard ML compiler that is written ia Standard ML using the module system.