Playing with Swift

swift-functions

// Interesting pieces of code while I learn the language
import UIKit


func isPrime(number: Int) -> Bool {
    let basicPrimes = [1,2,3,5,7,11,13,17,19]
    let basicNonPrimes = [0,4,6,8,9,10,12,14,15,16,18,20]
    if contains(basicPrimes, number) {
        return true
    } else if contains(basicNonPrimes, number) {
        return false
    }
    for var i = 2; i < (number + 1) / 2; i++ {
        if number % i == 0 {
            return false;
        }
    }
    return true;
}


func measure(title: String!, call: () -> Void) {
    /*
    Meassures the time spent to run a block of code.
    Source: https://medium.com/swift-programming/secret-of-swift-performance-a8ee86060843
    
    Example:
    
    measure("New") {
        var arr1: [Int] = []
        for var i = 1; i < 100; i++ {
            if isPrime(i) {
                arr1.append(i)
            }
        }
    }
    */
    
    let startTime = CACurrentMediaTime()
    call()
    let endTime = CACurrentMediaTime()
    if let title = title {
        print("\(title): ")
    }
    println("Time - \(endTime - startTime)")
}


import Foundation


class File {
    /*
    A simple class to facilitate basic interactions with a text file.
    Source: https://gist.github.com/frozzare/d4a9bbeb39e5425e7c26
    
    Example:
    
    let write: Bool = File.write("/tmp/mario.txt", content: "Mario here looking at Leticia")
    let read: String? = File.read("/tmp/mario.txt")
    */
    class func exists (path: String) -> Bool {
        return NSFileManager().fileExistsAtPath(path)
    }
    
    class func read (path: String, encoding: NSStringEncoding = NSUTF8StringEncoding) -> String? {
        if File.exists(path) {
            return String(contentsOfFile: path, encoding: encoding, error: nil)!
        }
        return nil
    }
    
    class func write (path: String, content: String, encoding: NSStringEncoding = NSUTF8StringEncoding) -> Bool {
        return content.writeToFile(path, atomically: true, encoding: encoding, error: nil)
    }
}