Re: Hashing, and NSDictionaries

[Stephen Brandon]

Aha! (lightbulb goes on). Thanks for the explanation - that makes a lot of 
sense.

The issue for me is to do with "MKPart" objects, which hold very long lists 
of MKNotes. Each MKNote has a whole lot of parameters.

If a MKPart is copied, all the MKNotes are copied too (deep copy), which 
means that a proper comparison between 2 parts has to go through and check 
all the notes in turn.

Hmmm... in this case, when there aren't likely to be that many parts, is the 
best thing to do to provide a faster and less accurate hash function, and 
then a more intelligent isEqual: method which is able to short-circuit as 
soon as it finds a difference between 2 parts?

My mistake was to assume that creating a hash would provide an absolute 
comparison - for these object, a "near enough" but very fast hash will do I 
think.

Cheers,
Stephen Brandon