Swift AnyIterator micro benchmark

main.swift

//
//  main.swift
//  microbenchmark
//
//  Created by Christopher Durham on 7/29/16.
//  Copyright © 2016 Christopher Durham. All rights reserved.
//

import Foundation

let TRIALS = 10_000
let ITEMS = 10_000

var test: [TimeInterval] = []

let startTest = Date()

for _ in 1...TRIALS {
    let array = Array(repeating: 5, count: ITEMS)
    var iterator = array.makeIterator()
    
    let startRegular = Date()
    while let i = iterator.next() { }
    let endRegular = Date()
    
    var iterator2 = AnyIterator(array.makeIterator())
    
    let startAny = Date()
    while let i = iterator2.next() { }
    let endAny = Date()
    
    let regular = endRegular.timeIntervalSince(startRegular)
    let any = endAny.timeIntervalSince(startRegular)
    
    test.append(any - regular)
}

let endTest = Date()
let testTime = endTest.timeIntervalSince(startTest)

let sum = test.reduce(0, combine: +)
let avg = sum / Double(test.count)

let max = test.reduce(DBL_MIN, combine: {$0 > $1 ? $0 : $1})
let min = test.reduce(DBL_MAX, combine: {$0 < $1 ? $0 : $1})

print(String(format:"A difference of %f s for \(ITEMS) items over \(TRIALS) trials", avg))
print(String(format: "with a max of %f and a min of %f . The test took %f s.", max, min, testTime))
print()

/*
A difference of 0.005833 s for 10000 items over 10000 trials
with a max of 0.021026 and a min of 0.005713 . The test took 59.240558 s.

Program ended with exit code: 0
*/