Stack + Queue

I find myself building these classes all the time, so I decided to create them in a feature complete way once and for all. They're pretty simple, but they're designed to behave as similarly to foundation-level collections as possible.

Usage

Stack

Stack *myStack = [[Stack alloc] init];              // []

[myStack push:@"A"];                                // ["A"]
[myStack push:@"B"];                                // ["A", "B"]

[myStack pushObjects:@[@"C", @"D", @"E"]];          // ["A", "B", "C", "D", "E"]

NSString *last = [myStack peek];                    // "E"

[myStack pop];                                      // ["A", "B", "C", "D"]

Queue

Queue *myQueue = [[Queue alloc] init];              // []

[myStack enqueue:@"A"];                             // ["A"]
[myStack enqueue:@"B"];                             // ["A", "B"]

[myStack enqueueObjects:@[@"C", @"D", @"E"]];       // ["A", "B", "C", "D", "E"]

NSString *first = [myStack peek];                   // "A"

[myStack dequeue];                                  // ["B", "C", "D", "E"]

Features

Objective-C Lightweight Generics

Stack<NSString *> *myStack = [Stack<NSString *> stack];     // Generic String Stack

[stack push:@"1"];                                          // OK
[stack push:@1];                                            // NOT OK

Objective-C Fast Enumeration

Queue<NSNumber *> *myQueue = [Queue queueWithObjects:@1, @2, @3, @4, nil];

for (NSNumber *number in myQueue) {

    // iterate

}

Subscripting

Stack<NSString *> *myStack = [Stack stackWithArray:@[@"A", @"B", @"C", @"D"]];

NSString *first = myStack[0]                        // "A"
NSString *second = myStack[1]                       // "B"

Equality, Hashability, Encodability

Queue<NSNumber *> *myQueue = [Queue queueWithArray:@[@1, @2, @3, @4]];
Queue<NSNumber *> *myQueue2 = [Queue queueWithArray:@[@1, @2, @3, @4]];

[myQueue isEqualToQueue:myQueue2]                   // YES
[myQueue2 isEqual:myQueue]                          // YES
myQueue.hash == myQueue2.hash                       // YES

NSData *myQueueData = [NSKeyedArchiver archivedDataWithRootObject:myQueue];
Queue<NSNumber *> *myQueue3 = (Queue<NSNumber *> *)[NSKeyedUnarchiver unarchiveObjectWithData:myQueueData];

[myQueue3 isEqual:myQueue]                          // YES

Mass Key-Value Observation

You can observe every object in a stack or a queue using: -addObserver:toObjectsAtIndexes:forKeyPath:options:context:

You can remove observers using: -removeObserver:fromObjectsAtIndexes:forKeyPath:

Sorting & Filtering

See the documentation for details on the various methods for deriving or mutating sorted / filtered stacks & queues.

Documentation

Documentation is made with Jazzy, and is hosted on GitHub pages. You can find it here