Jens, thanks for clearing up the thing about the selector defining a message (method plus parameters) rather than a method and thus not being tied to a class.
On Thu, Oct 22, 2009 at 1:21 AM, Jens Alfke <j...@mooseyard.com> wrote: > > On Oct 21, 2009, at 9:43 AM, Jim Kang wrote: > > That selector is a unique index that points to a method of a specific > class. > > > No, that's not true of Objective-C (although it is of C++ method-pointers.) > A selector is, basically, just a unique string: it defines a *message*, > not a method, to use the old Smalltalk OOP terminology. > However, a selector is not a string. I was just listening to this podcast with Mike Ash, and he discusses this around the 9:23 mark or so: http://podcast.mobileorchard.com/episode-23-mike-ash-on-the-objective-c-runtime-objects-and-the-runtime-message-sending-and-no-such-method/ He explains that comparing strings is too slow for the runtime to use for finding messages and so it uses integers to represent the messages and calls them selectors. > Any class that implements a method with that name uses the same selector > for it, regardless of inheritance. > > To be specific, if I create two unrelated classes A and B, each of which > implements a -foo method, the selector @selector(foo) is used for both. > This is really good to know. _______________________________________________ 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
