On Tue, Mar 16, 2010 at 11:35 AM, Thomas Davie <tom.da...@gmail.com> wrote: >> Your code doesn't account for the possibility that the order of >> comparison might happen in the other order (i.e. [@"123" isEqual: >> object]). I wouldn't be surprised if NSSet is assuming that equality >> is transitive (i.e. [a isEqual: b] == [b isEqual: a]). > > For reference, this property is not transitivity, the transitivity relation > is: > > a -> b ^ b -> c => a -> c (for some relation ->) > > The one you're looking for is commutativity.
Indeed; must have been echos of my previous life as a C++ programmer creeping into the Obj-C part of my brain (in C++, the std::set class uses less than, instead of equality, where transitivity is the important property, not commutativity). :) -- Clark S. Cox III clarkc...@gmail.com _______________________________________________ Cocoa-dev mailing list (Cocoa-dev@lists.apple.com) Please do not post admin requests or moderator comments to the list. Contact the moderators at cocoa-dev-admins(at)lists.apple.com Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com This email sent to arch...@mail-archive.com
