ArraySet

This is ArraySet implementation in Swift. ArraySet is a data structure where elements are unique and sorted so you can:

• read elements directly using subscript - like an Array
• insert and remove elements - like a Set
• find index of a given element in O(log N) complexity

Implementation is based on keeping internal sorted array and preventing duplicates.

Basic protocols

public protocol SortedCollection {
    associatedtype Element: Comparable
    var sortedElements: [Element] { get }
}

public protocol MutableIndexReversableCollection {
    associatedtype Element
    mutating func remove(at index: Int) -> Element
    mutating func insert(_ element: Element) -> Int
    mutating func remove(_ element: Element) -> Int?
}

public protocol IndexReversableCollection {
    associatedtype Element
    func firstIndex(of element: Element) -> Int?
    func lastIndex(of element: Element) -> Int?
}

public protocol UniqueIndexReversableCollection {
    associatedtype Element
    func index(of element: Element) -> Int?
}

Compounded protocols

protocol SortedArrayProtocol:
    RandomAccessCollection,
    SortedCollection,
    MutableIndexReversableCollection,
    IndexReversableCollection {}

protocol ArraySetProtocol:
    RandomAccessCollection,
    SortedCollection,
    MutableIndexReversableCollection,
    UniqueIndexReversableCollection {}

Exmples:

Using ArraySet:

        let arraySet = ArraySet(elements: [1, 2, 0, 2])
        XCTAssertEqual(arraySet.sortedElements, [0, 1, 2])

Using SortedArray:

        let sortedArray = SortedArray(elements: [1, 2, 1])
        XCTAssertEqual(sortedArray.sortedElements, [1, 1, 2])