Writing for OS/X or the iPhone? Using NSDictionary to store and access key-value pairs? Ever tried to enumerate them all only to find they come back in some random order? As NSDictionary uses a hash table to map keys to values, it maintains no sort order whatsoever across its entries. The SortedDictionary class and its mutable companion, MutableSortedDictionary implement dictionaries that maintain a strong sort order across their keys. SortedDictionary and MutableSortedDictionary deliver high performance using an implementation of a self-balancing binary tree.

The SortedDictionary and MutableSortedDictionary classes implement the interfaces of NSDictionary and NSMutableDictionary, respectively, and can serve as drop-in replacements. They support the NSCoding, NSCopying and NSMutableCopying protocols. Additionally, the sorted dictionary classes add methods allowing you to enumerate entries in both their forward and reverse key order, without having to sort and without any additional computational cost.

Add the SortedDictionary folder to your project. Add all the files in the SortedDictionary folder, including its Internal and External folders, into your project. When you build your project, the sorted dictionaries classes will be compiled into your application. To create a sorted dictionary in code, include the appropriate header file:

#import "SortedDictionary.h"

- (void) someMethod {
   SortedDictionary *dict = [MutableSortedDictionary dictionary];

   [dict setValue: @"red" forKey: @"apple"];
   [dict setValue: @"yellow" forKey: @"banana"];
   [dict setValue: @"orange" forKey: @"orange"];

   NSString *color = [dict objectForKey: @"apple"];
}

Add the compiled frameworks to your project:

MIT License

Copyright (c) 2009 Oren Trutner

Modified by Yuriy Shevchuk, struktur AG, on 8/30/2013.

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