4.3 Compilation: the Project structure

4.3.1 Projects and program units

We say that the project compilation system's unit of compilation is a program unit. A program unit is a file containing part of an ML program that might be represented in source format or object (compiled) format. If it is a source file it has the name unit-name.sml, and if it is an object file, it has the name unit-name.mo.

We call the set of program units that makes up the ML program you are working on a project.