title: Number of elements in NSArray where (....)
body: <p>I am used to working in C# using the linq extensions (list.select(...).where(...) ext), and I was wondering if there was some way of doing the same sort of thing in Objective-C. This would save me from building a number of rather complicated queries using Core Data, which is great for some things, but perhaps not the best for complex queries (or maybe I'm just uninformed).</p>
  
  <p>Is there some kind of equivalent for linq in Objective-C/Core Data?</p>
  
  <p><strong>EDIT:</strong> More specifically, I would like to count the number of elements that fit some criteria. Say my model has a field called date. I am trying to select the distinct dates, and then calculate how many of each date there are. In SQL this would be like a group by, and a COUNT aggregate.</p>