Functors in Swift - A simple introduction

Note: This Playground is written in Swift 2.0 and Xcode 7 Beta 3.

This is the playground for my lightning talk at July's 2015 Melbourne CocoaHeads.

The talk is a simple introduction to Functors and Monads in Swift, focusing on the practical use of these concepts, rather than their mathematical definition.

The cool things about Functors and Monads are map and flatMap. Using these we can simplify code like this:

func getFancyEmojiForUser() -> String? {
  if let actuallyAUser = userFromDatabase() {
    let joinedUserName = joinedName(actuallyAUser)

    if let emojiForUser = emojiFromString(joinedUserName) {
      return fancifyEmoji(emojiForUser)
    }
  }

  return .None
}

into something that is easier to write and specially easier to reason about.

func getFancyEmojiForUser() -> String? {
  return userFromDatabase()
    .map(joinedName)
    .flatMap(emojiFromString)
    .map(fancifyEmoji)
}

If you are interested in this tweet me @mokagio or visit mokacoding

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(c) 2015 - Giovanni Lodi