Hi guys,
Something I've been wanting to ask the community for years, but never had the gumption, was about changing how we write our #= and #hash methods, but now that we're combing through them anyway, I must!
Basically, it comes down to Proxy's. I want them to work better in Squeak. But every time we put another send to #class or #== in an implementation of #=, since those methods are inlined, they're too brittle to work with Proxy's. This causes hard-to-trackdown bugs in applications and mini-messes to deal with them since the app is forced to change its code to become "aware" of potential Proxy'iness of an object before comparing it with #=.
This is no surprise, since writing a send to #== instead of #= for no more than "performance" is actually breaking encapsulation in the first place...
There is an easy solution. When writing #= and #hash implementations, use (#species or #xxxClass or #isKindOf: instead of #class) and #= instead #==. So, for example, Eliot, I want to upgrade your new Message>>#= to something like:
= anObject ^self xxxClass = anObject xxxClass and: [selector = anObject selector "selector lookup is by identity" and: [lookupClass = anObject lookupClass and: [args literalEqual: anObject arguments]]]
Or #species or #isKindOf:, like we do in many other methods. Now the method is Proxy-compatible.
What do you think?