CreateDirectory does create the actual disk directory, and return a new representation of it.

NewDiffVersion creates a new DiffVersion with the named version.

RunDiff uses the factory to parse file arguments, find the version to diff, and find each Info object for each files, and runs against the differ.

Differ creates two DiffVersion and diffs them.

DiffProgram finds and run the diff program.

DiffVersion gets the proper version of objects, and aggregate them into a directory.

Directory creates a new temp directory, and allows to easily create new files.

InfoObject is an implementation of the Object interface.

Printer is used to print an object.

Object is an interface that let's you retrieve multiple version of it.