bennokress

extension Collection {

    // Usage: array[optional: 2] --> returns element at position 2 if possible, else returns nil
    subscript(optional i: Index) -> Iterator.Element? {
        return (self.startIndex ..< self.endIndex).contains(i) ? self[i] : nil
    }

}

bennokress

import UIKit

extension String {
    
    var image: UIImage? { return UIImage(from: self) }
    
}

extension UIImage {
    

bennokress

for case let button as UIButton in self.view.subviews {
    button.setTitleForAllStates("") // or something else
}

bennokress

extension Date {

    var isToday: Bool { return Calendar.current.isDateInToday(self) }
    
    /// Returns a Date with the specified days added to the one it is called with
    func adding(years: Int = 0, months: Int = 0, days: Int = 0, hours: Int = 0, minutes: Int = 0, seconds: Int = 0) -> Date {
        var targetDay: Date
        targetDay = Calendar.current.date(byAdding: .year, value: years, to: self)!
        targetDay = Calendar.current.date(byAdding: .month, value: months, to: targetDay)!
        targetDay = Calendar.current.date(byAdding: .day, value: days, to: targetDay)!

bennokress

extension Dictionary where Value == Any {
  
    // Usage: dict.value(forKey: "age", defaultValue: 100) … works with every type!
    func value(forKey key: Key, defaultValue: @autoclosure () -> T) -> T {
        guard let value = self[key] as? T else {
            return defaultValue()
        }

        return value
    }

bennokress

extension Bool {
    
    static func random(trueProbability: Int = 50) -> Bool {
        // NEEDS THE INT EXTENSION for a random Int! --> IntExtensions.swift
        return Int.random(between: 1, and: 100) <= trueProbability ? true : false
    }
    
}

bennokress

extension Array {
    
    // Usage: [1,2,3,4].shifted(by: 2) --> [3,4,1,2] or "hello".shifted(by: -1) --> "elloh"
    func shifted(by shiftAmount: Int) -> Array {
        guard self.count > 0, (shiftAmount % self.count) != 0 else { return self }
        let moduloShiftAmount = shiftAmount % self.count
        let effectiveShiftAmount = moduloShiftAmount < 0 ? moduloShiftAmount + self.count : moduloShiftAmount
        let shift: (Int) -> Int = { return $0 + effectiveShiftAmount >= self.count ? $0 + effectiveShiftAmount - self.count : $0 + effectiveShiftAmount }
        return self.enumerated().sorted(by: { shift($0.offset) < shift($1.offset) }).map { $0.element }
    }

bennokress

extension Int {
    
    static func random(between min: Int, and max: Int) -> Int {
        return min + Int(arc4random_uniform(UInt32(max - min + 1)))
    }
    
    /// Returns the digits in self
    var digits: Int {
        return self.abs < 10 ? 1 : 1 + (self / 10).digits
    }

bennokress

extension String {

    /// Usage: "Hello World".until(" World") --> "Hello"
    mutating func until(_ string: String) {
        var components = self.components(separatedBy: string)
        self = components[0]
    }
    
    /// Blows a string up to totalLength by pre- and postfixing characters (e.g. "hello".withAddedDivider("-", totalLength: 13) returns "--- hello ---")
    func withAddedDivider(_ divider: Character, totalLength: Int, padding: Int = 1) -> String {

bennokress

extension Equatable {
    
    // Usage: 3.isAny(of: 0, 1, 2, 3) // true
    func isAny(of candidates: Self...) -> Bool {
        return candidates.contains(self)
    }
    
}