Creating a dictionary who's objects are also linked or indexed?

FROM : Phil
DATE : Sat Aug 12 21:00:17 2006

I'm curious if there is a better Cocoa solution than I've found to 
the following problem:  I often have a list of items (strings, 
numbers, or dates) where I know the values of the first and last 
items and need to iterate over the inclusive set of items that fall 
between the first and last items.  I can accomplish this by 
effectively implementing the lookup capability of a dictionary in an 
object contained in an array or by adding an index to an object in a 
dictionary.  It can also be handled using Core Data which seems a lot 
like using a sledgehammer to swat a fly.

For example, I have a list of names and want to enumerate over the 
set of items from a given item to a given item.  My code determines 
that "Ball" is the first value of interest and "Smith" is the last 
value, and given these, I need to return the inclusive set of items 
that fall between (simple alpha comparison) these values in the 
parent set.

It seems like a fairly common problem and am wondering if Cocoa 
provides a simpler solution that I'm not seeing?