##Adds Swift Array Extensions for Stack & Queue operations.
import Foundation
//Mutating keyword offers no thread-safe guarantees
extension Array {
//Stack - LIFO
mutating func push(newElement: T) {
self.append(newElement)
}
mutating func pop() -> T? {
return self.removeLast()
}
func peekAtStack() -> T? {
return self.last
}
//Queue - FIFO
mutating func enqueue(newElement: T) {
self.append(newElement)
}
mutating func dequeue() -> T? {
return self.removeAtIndex(0)
}
func peekAtQueue() -> T? {
return self.first
}
}
//
// Examples
//
//Stack Example
var stack = [String]()
//Word processing actions Array
let actions = ["Font-Color", "Font-Size", "Font-Weight"]
//Add each action to the Stack
for action in actions {
stack.push(action)
}
//Peek at action
var action = stack.peekAtStack()
println("Peek at action: \(action)")
//Pop Action off the Stack
action = stack.pop()
println("Pop action off: \(action)")
//...
//Queue Example
var queue = [Int]()
//Order Ids Array
let orders = [1976787, 2643009, 3762923]
//Add each order into Queue
for order in orders {
queue.enqueue(order)
}
//Peek at order
var order = queue.peekAtQueue()
println("Peek at Order Id: \(order)")
//Process each order as recieved
order = queue.dequeue()
println("Dequeue Order Id: \(order)")
//...