NSPredicate that calls test method to fetch results from Core Data

I am not quite sure how to word this question without explaining what I am trying to do.

I have a managed object context filled with (essentially) cir开发者_Python百科cles that have an x,y coord for the center point and a radius.

I would like to construct a predicate for my core data retrieval that will find all circles that overlap with a given circle.

I can write a boolean method that tests this and returns true or false, but my problem is that I don't know how to call this testing method in my predicate.

in pseudo-code, I am trying to do this:

NSPredicate *pred = [NSPredicate (if [testOverlapWithCenterAt:centerOfGivenObjectInContext andRadius:radiusOfGivenObjectInContext]);

Perhaps NSPredicate isn't even the best way to do this. Any help would be much appreciated.

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You can use the predicateWithBlock instance method of NSPredicate. Give it a try.