1.6: Modules

Every Standard ML program is composed of modules. Modules group together a set of definitions. Here, we define a module named Modules by using the structure keyword, with one definition, fun favouriteNum ().

This program makes use of three other modules: String, Int, and Random.

• String is opened, bringing its definitions into the environment of the Modules module. The function ^ comes from the String module, and concatenates two strings.
• Random is aliased as R, to shorten its usage, while avoiding polluting the environment with its definitions directly.
• Int is used directly.