Add documentation

Source/AnyKey.swift

@@ -10,9 +10,14 @@ import Foundation
 
 /// This code was taken from:
 /// http://stackoverflow.com/questions/24119624/how-to-create-dictionary-that-can-hold-anything-in-key-or-all-the-possible-type
+///
+/// `AnyKey` is a simple struct that conforms to `Hashable` to allow any other `Hashable` key to be used in the cache dictionary
 struct AnyKey: Hashable {
+	/// The underlying value
 	private let underlying: Any
+	/// The hashing function
 	private let hashValueFunc: () -> Int
+	/// The equality function
 	private let equalityFunc: (Any) -> Bool
 
 	init<T: Hashable>(_ key: T) {
@@ -31,6 +36,7 @@ struct AnyKey: Hashable {
 		}
 	}
 
+	/// `Hashable` protocol conformance
 	var hashValue: Int { return hashValueFunc() }
 }
 

Source/KingCache.swift

@@ -8,17 +8,24 @@
 
 import Foundation
 
+/// `KingCache` is a simple cache that can hold anything, including Swift structs, enums, and values.
+/// It is designed to work similar to the `NSCache`, but with native Swift support.
+///
 public class KingCache {
 	// MARK: - Private variables
+	/// An array of `NSNotificationCenter` observers that need to be removed upon deinitialization
 	private var notificationObservers: [NSObjectProtocol] = []
 
 	// MARK: - Internal variables
+	/// The dictionary that holds the cached values
 	var cacheDictionary: [AnyKey: Any] = [:]
 
 	// MARK: - Public variables
+	/// The number of items in the cache
 	public var count: Int {
 		return cacheDictionary.count
 	}
+	/// The limit of the amount of items that can be held in the cache. This defaults to 0, which means there is no limit.
 	public var countLimit: UInt = 0 {
 		didSet {
 			evictItemsIfNeeded()
@@ -52,6 +59,9 @@ public class KingCache {
 	}
 
 	// MARK: - Internal methods
+	/// Evicts items if the `countLimit` has been reached.
+	/// This currently uses a random eviction policy, kicking out random items until the `countLimit` is satisfied.
+	///
 	func evictItemsIfNeeded() {
 		if countLimit > 0 && cacheDictionary.count > Int(countLimit) {
 			// TODO: Evict items with more rhyme or reason
@@ -65,11 +75,24 @@ public class KingCache {
 	}
 
 	// MARK: - Public methods
+	/// Adds an item to the cache for any given `Hashable` key.
+	///
+	/// - parameter item: The item to be cached
+	/// - parameter key: The key with which to cache the item
+	///
 	public func setItem<K: Hashable>(item: Any, forKey key: K) {
 		cacheDictionary[AnyKey(key)] = item
 		evictItemsIfNeeded()
 	}
 
+	/// Gets an item from the cache if it exists for a given `Hashable` key.
+	/// This method uses generics to infer the type that should be returned.
+	///
+	/// Note: Even if an item exists for the key, but does not match the given type, it will return `nil`.
+	///
+	/// - parameter key: The key whose item should be fetched
+	/// - returns: The item from the cache if it exists, or `nil` if an item could not be found
+	///
 	public func itemForKey<T, K: Hashable>(key: K) -> T? {
 		if let item = cacheDictionary[AnyKey(key)] as? T {
 			return item
@@ -77,16 +100,24 @@ public class KingCache {
 		return nil
 	}
 
+	/// Discards an item for a given `Hashable` key.
+	///
+	/// - parameter key: The key whose item should be removed
+	///
 	public func removeItemForKey<K: Hashable>(key: K) {
 		cacheDictionary[AnyKey(key)] = nil
 	}
 
+	/// Clears the entire cache.
+	///
 	public func removeAllItems() {
 		cacheDictionary.removeAll()
 	}
 
 	// MARK: - Subscript methods
 	// TODO: Consolidate these subscript methods once subscript generics with constraints are supported
+	/// A subscript method that allows `Int` key subscripts.
+	///
 	public subscript(key: Int) -> Any? {
 		get {
 			return itemForKey(key)
@@ -101,6 +132,8 @@ public class KingCache {
 		}
 	}
 
+	/// A subscript method that allows `Float` key subscripts.
+	///
 	public subscript(key: Float) -> Any? {
 		get {
 			return itemForKey(key)
@@ -115,6 +148,8 @@ public class KingCache {
 		}
 	}
 
+	/// A subscript method that allows `String` key subscripts.
+	///
 	public subscript(key: String) -> Any? {
 		get {
 			return itemForKey(key)