Swift Toolbox

I don’t expect anyone to like this or use this, stuff here can be very opinionated.

Some examples:

• Bool constants yes and no.

• Postfix testing operators optional.? and isEnabled.!.

• Literal suffixes 45° for angles and 75% for percentages.

• Literal suffixes 5.min, 30.sec, and 300.ms for time intervals.

• Operators ++ and -- without undefined behavior.

• Deprecated integer division, 10/3 now correctly returns 3.333....

• Operators for powers 2^^5 and roots √2.

• Extended String interpolation for formatting numbers:

  "Automatic: \(x, .pretty)"  // same as %g in printf() 
  "Fixed: \(pi, 3))"  // 3.142
  "Degrees: \(pi, (°))"  // 180°
  "Percents: \(opacity, %, 1))"  // 42.5%
  

• Building system for date formats with automatic localization:

  dateFormatter.format = .localized([.time, .weekday, .day, .month])  // "h:mm a eeee, d MMMM"
  dateFormatter.format = .exact([.day(.padded), .slash, .month(.paddedNumber)])  // "dd/MM"
  

• NumberFormatter and DateFormatter support in String interpolation:

  "Today is \(now, localized: .weekday)."  // specifying format ad-hoc
  "Since \(date, formatter)."  // using custom formatter object
  "Result is \(result, localized: 0...3)"  // formatted up to 3 fractional digits
  "Total \(total, formatter)."  // using custom formatter object
  

• Assertion operator that throws custom Error and generic Assert error that captures context:

   let first = try array.first !! Assert("List must not be empty.")
   try value > 0 !! Assert("Value must be positive.")
   try number.isFinite !! EncodingError.invalidValue
  

• Construction of URL from String literal:

  let link: URL = "https:​//apple.com"
  let app: URL = "/Applications/Xcode.app"
  

• Simple constructors for Timers:

  Timer.after(10.sec) { ... }
  Timer.every(10.sec) { ... }
  

• Simple observation of Notifications:

  let observation = UIApplication.didBecomeActiveNotification.observe { notification in
      // Handle observation.
  }
  

• Multiple equality testing:

  direction == (.up | .down)  // direction is either up or down
  string.contains("+" & "-")  // string contains both plus and minus signs
  

• Property wrapper for clamping values @Clamped(0...1) or @Clamped(0...), also works on Optional values.

• Property wrapper @UserDefault with proper semantics, supports for enums, and observation of changes.