Performance for Iterations In Swift

IterationPerf.swift

//
//  IterationPerfTests.swift
//  IterationPerfTests
//
//  Created by David Owens II on 12/11/15.
//  Copyright © 2015 owensd.io. All rights reserved.
//

import XCTest
@testable import IterationPerf

let first = 10000000
let second = 20000000

class IterationPerfTests: XCTestCase {
    
    func testZipStride() {
        self.measureBlock {
            var sum = 0
            for (i, j) in zip(first.stride(to: 0, by: -1), second.stride(to: 0, by: -2)) {
                if i % 2 == 0 { continue }
                if j % 3 == 0 { continue }
                sum += 1
            }
            print(sum)
        }
    }
    
    func testCStyleFor() {
        self.measureBlock {
            var sum = 0
            for var i = first, j = second; i > 0 && j > 0; i -= 1, j -= 2 {
                if i % 2 == 0 { continue }
                if j % 3 == 0 { continue }
                sum += 1
            }
            print(sum)
        }
    }
    
    func testWhileLoop() {
        self.measureBlock {
            var sum = 0
            
            if true {
                var i = first, j = second
                while i > 0 && j > 0 {
                    defer {
                        i -= 1
                        j -= 2
                    }
                    
                    if i % 2 == 0 { continue }
                    if j % 3 == 0 { continue }
                    sum += 1
                }
            }
            
            print(sum)
        }
    }
    
}