May 26, 2018
Provides Moose-like method modifiers
Method modifiers are a powerful feature from the CLOS Common Lisp Object System world.
In its most basic form, a method modifier is just a method that calls $self->SUPERfoo@_. I for one have trouble remembering that exact invocation, so my classes seldom re-dispatch to their base classes. Very bad!
ClassMethodModifiers provides three modifiers before, around, and after. before and after are run just before and after the method they modify, but can not really affect that original method. around is run in place of the original method, with a hook to easily call that original method.
One clear benefit of using ClassMethodModifiers is that you can define multiple modifiers in a single namespace. These separate modifiers don’t need to know about each other. This makes top-down design easy. Have a base class that provides the skeleton methods of each operation, and have plugins modify those methods to flesh out the specifics.
In short, ClassMethodModifiers solves the problem of making sure you call $self->SUPERfoo@_, and provides a cleaner interface for it.