Every Alan file is made up of two parts, the
body. In Alan all imports must be declared at the beginning of the file, and once anything else is declared
imports are no longer allowed.
body is simply everything else that can be declared in the file:
event handlers. Of these everything but
event handlers can be
exports that can be used by other modules, even things simply imported from another module. These two levels of "visibility" in the file are part of an implied structure: scope.