Inhabited

A collection that cannot be empty

Installation

SPM

Add the following to your Package.swift dependencies:

.package(url: https://github.com/klaaspieter/Inhabited, .branch("master"))

Usage

// Non empty Arrays
Inhabited([]) // .none
Inhabited([1, 2, 3, 4] // Inhabited(1, 2, 3, 4])?

// Non empty Strings
Inhabited("") // .none
Inhabited("hello") // Inhabited("hello")?

// Filter
Inhabited("hello")?.filter({ _ in false }) // .none
Inhabited("hello")?.filter({ $0 == "l" }) // Inhabited("ll")
let array: [Int] = Inhabited("hello")?.filter({ _ in false }) // []

Partial RangeReplaceableCollection conformance

RangeReplaceableCollection requires replacingSubrange(:with:) and an empty init. Implementing it would force us to crash when the last elements is removed. Instead only the mutating addition methods are implemented. The removal methods are all non-mutating and return a new Inhabited or .none if the collection becomes empty.

// insertions
var collection = Inhabited("h")
collection?.append("i") // Inhabited("hi")

var collection = Inhabited("lo")
collection?.insert(contentsOf: "hel", at: 0) // Inhabited("hello")

// removals
let collection = Inhabited("hhello")?.removing(at: 0) // Inhabited("hello")
let collection = Inhabited("h")?.removing(at: 0) // .none
Inhabited("hello")?.replacingSubrange(0...4, with: "")) // .none