kristopherjohnson

protocol CanBark {
    func bark() -> String
}

class Animal {
    func animalType() -> String {
        return "Animal"
    }
}

mxswd

// this is a playground
protocol Nat {
  class func construct() -> Self
  class func value() -> Int
}

struct Z : Nat {
  static func construct() -> Z {
    return Z()
  }

CodaFi

// Playground - noun: a place where people can play

protocol ℕ {
	static func construct() -> Self
	static var value : UInt { get }
}

struct Zero : ℕ {
	static func construct() -> Zero {
		return Zero()

cobbal

protocol Monad {
    typealias F
    typealias U
    class func bind<M : Monad where M.U == U>(Self, F -> M) -> M
    class func `return`(F) -> Self
}


extension Array : Monad {
    typealias F = T