Case for local class methods
Here is a use case for local class methods.
Say we wish to give certain classes and all subclasses a special name.
class Y < X; end
class Z < Y; end
Z.special_name #=> "special:Z"
But what if Y has a unique special name?
class Y < X
Problem that arises:
Z.special_name #=> "unique:Y" # wrong!
Currently, to solve this would require creating an additional method, e.g.
unique_name and redefine
special_name to first look for unique_name then fallback to default special name if non-found. It works, but adds additional complexity to API.
Nicer solution would be local class methods.
class Y < X def special_name 'unique:Y' end local :special_name end Y.special_name #=> "unique:Y" Z.special_name #=> "special:Z"
The idea being that local class methods are skipped in super/lookup chain.
This idea is not without precedence. Module class methods can be thought of as being local. So this idea has other side of the notion, that modules could have class methods that are not skipped over in the super/lookup chain. In that case we would need a term that means opposite of local, so I'll use
module M def self.q; "q"; end nonlocal :q end class X include M end X.q #=> "q"