Namespaces

In addition to adding methods to classes and providing out-of-the-box functionality as part of the module, another major purpose of modules is to provide a namespace. A namespace is just what it sounds like: it provides a scope or space for naming. In particular, it provides a space for constants. With the exception of raw global methods, the entry point for most code will be through a constant, whether it be a class constant or a module constant.

We've learned how to create classes and modules. Really, what we are doing is creating constants that point to those objects in memory. When we create constants (classes, modules, or otherwise) in IRB, we are creating a constant in the global namespace. This can quickly get crowded, especially if you are creating a class or module constant that may have a common name.

For instance, in the previous topic, we created an Enum module. Enum is a very common word in the Ruby world, and do we really think our Enum module...