2014/1/24 Sean P. DeNigris <[email protected]> > Thank you everyone. Yes, the subject is a bit misleading ;) I'll give you > my > exact use case to make things clearly… > > I'm cleaning up the globals ActiveWorld and World. There are methods such > as > Morph>>world that sometimes return one of the above, or nil. As part of the > cleanup, I want a NullWorld that is indeed polymorphic with WorldMorph. > However, I don't want to change too much at once because it's too easy to > freeze the image. So I want to temporarily implement > NullWorld>>#ifNil:ifNotNil: so that I can plug in the new object, without > breaking all the existing code, so I can switch back to nil if I get in > trouble. When it's working, I'll start to remove all the #ifNil:ifNotNil: > sends as a 2nd phase. > > In light of this, what's the best way to proceed? > > > > ----- > Cheers, > Sean > -- > View this message in context: > http://forum.world.st/Null-Object-Pattern-tp4738574p4738906.html > Sent from the Pharo Smalltalk Developers mailing list archive at > Nabble.com. > >
Do you know this places where ifNil:ifNotNil: is called? If so, you coulde change them to ifWorldNil:ifWorldNotNil: and implement this on World, ActiveWorld, NullWorld and UndefinedObject.
