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Re: dynamic vs. static typing
On Nov 18, 2003, at 2:25 PM, Ken Shan wrote:
> Funny how existential types keep coming up. (:
> Konstantin Läufer. 1996. Type classes with existential types.
> Journal of Functional Programming 6(3): 485-517.
> (By the way, if all you know about the List is that it contains a bunch
> of objects, and if there is nothing that you can do with every object
> that is, if there is no message that every object responds to -- then
> it is a pretty useless List, which you might as well replace with a
> nonnegative integer.)
What if I want to send a message to all the objects in the list that
respond to a method, but not to those that don't? For example, let's
say I have a list of things in my house and I want to send a turnOff
message to everything that can be turned off.