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https://github.com/RuiAAPeres/OptionalExtensions

Swift µframework with extensions for the Optional Type
https://github.com/RuiAAPeres/OptionalExtensions

functional-programming swift swift-extensions

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Swift µframework with extensions for the Optional Type

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README 

        
# OptionalExtensions







[![CocoaPods](https://img.shields.io/cocoapods/v/OptionalExtensions.svg)](https://cocoapods.org/)

[![Swift 4.0](https://img.shields.io/badge/Swift-4.0-orange.svg?style=flat)](https://developer.apple.com/swift/)

[![License MIT](https://img.shields.io/badge/License-MIT-lightgrey.svg?style=flat)](https://opensource.org/licenses/MIT)

![](https://camo.githubusercontent.com/410f44c161ebf367eacb1fcce9121e336e211bc6/68747470733a2f2f696d672e736869656c64732e696f2f62616467652f506c6174666f726d2d696f732532302537432532306f737825323025374325323077617463686f7325323025374325323074766f732d6c69676874677265792e7376673f7374796c653d666c6174)



Why?

----



Swift's Optional is pretty awesome, but it can always get better. This repository is an humble attempt to add some utility methods to it.



Operators

--------



* [filter](https://github.com/RuiAAPeres/OptionalExtensions#filter-wrapped---bool---optionalwrapped)

* [mapNil](https://github.com/RuiAAPeres/OptionalExtensions#mapnil-void---wrapped---optionalwrapped)

* [flatMapNil](https://github.com/RuiAAPeres/OptionalExtensions#flatmapnil-void---optionalwrapped---optionalwrapped)

* [then](https://github.com/RuiAAPeres/OptionalExtensions#then-wrapped---void---void-similar-to-ts-foreach)

* [maybe](https://github.com/RuiAAPeres/OptionalExtensions#maybe-u---wrapped---u---u-similar-to-haskells-maybe)

* [onSome](https://github.com/RuiAAPeres/OptionalExtensions#onsome-wrapped---void---optionalwrapped-injects-a-side-effect-in-the-some-branch)

* [onNone](https://github.com/RuiAAPeres/OptionalExtensions#onnone-void---void---optionalwrapped-injects-a-side-effect-in-the-none-branch)

* [isSome](https://github.com/RuiAAPeres/OptionalExtensions#issome-bool)

* [isNone](https://github.com/RuiAAPeres/OptionalExtensions#isnone-bool)



#### `filter: (Wrapped -> Bool) -> Optional`



```swift

let number: Int? = 3



let biggerThan2 = number.filter { $0 > 2 } // .Some(3)



let biggerThan3 = number.filter { $0 > 3 } // .None

```



#### `mapNil: (Void -> Wrapped) -> Optional`



```swift

let number: Int? = 3

number.mapNil { 2 } // .Some(3)



let nilledNumber: Int? = nil

nilledNumber.mapNil { 2 } // .Some(2)

```



#### `flatMapNil: (Void -> Optional) -> Optional`



```swift

let number: Int? = 3

number.flatMapNil { .Some(2) } // .Some(3)



let nilledNumber: Int? = nil

nilledNumber.flatMapNil { .Some(2) } // .Some(2)

```



#### `then: (Wrapped -> Void) -> Void` (similar to `[T]`'s `forEach`)



```swift

let number: Int? = 3

number.then { print($0) } // prints "3"



let nilledNumber: Int? = nil

nilledNumber.then { print($0) } // print won't be called

```



#### `maybe: U -> (Wrapped -> U) -> U` (similar to Haskell's `maybe`)



```swift

let number: Int? = 3

number.maybe(100) { $0 + 1 } // 4



let nilledNumber: Int? = nil

nilledNumber.maybe(100) { $0 + 1 } // 100

```



#### `onSome: (Wrapped -> Void) -> Optional` (injects a side effect in the `.Some` branch)



```swift

let number: Int? = 3

let sameNumber = number.onSome { print($0) } // prints "3" & returns .Some(3)



let nilledNumber: Int? = nil

let sameNilledNumber = nilledNumber.onSome { print($0) } // .None

```



#### `onNone: (Void -> Void) -> Optional` (injects a side effect in the `.None` branch)



```swift

let number: Int? = 3

let sameNumber = number.onNone { print("Hello World") } // .Some(3)



let nilledNumber: Int? = nil

let sameNilledNumber = nilledNumber.onNone { print("Hello World") } // prints "Hello World" & returns .None

```



#### `isSome: Bool`



```swift

let number: Int? = 3

let isSome = number.isSome // true



let nilledNumber: Int? = nil

let isSome = nilledNumber.isSome // false

```



#### `isNone: Bool`



```swift

let number: Int? = 3

let isSome = number.isNone // false



let nilledNumber: Int? = nil

let isSome = nilledNumber.isNone // true

```



Setup

-----



**Carthage:**



```

github "RuiAAPeres/OptionalExtensions"

```



**CocoaPods:**



```

pod "OptionalExtensions"

```



**Manually:**



Grab the [OptionalExtensions.swift](https://github.com/RuiAAPeres/OptionalExtensions/blob/master/OptionalExtensions/Source/OptionalExtensions.swift) file and drop it in your project. 



Contributing

-----------



We will gladly accept Pull Requests with new methods or improving the ones that already exist. Documentation, or tests, are always welcome as well. ❤️



License

-------



OptionalExtensions is licensed under the MIT License, Version 2.0. [View the license file](LICENSE)



Copyright (c) 2015 Rui Peres