Docker Image for SML/NJ

The various Linux distros package repos carry very outdated versions of the SML/NJ compiler. This Docker image builds the latest official SML/NJ release.

Symmetric Type Sharing in ML

In the Standard ML language, there are two primary mechanisms for refining a module signature after the fact. One is a symmetric mechanism called type sharing and the other called where type, aka fibration. These are useful for facilitating modular programming by enabling reuse of module signatures (i.e., the syntactic "type" of a module).