SwiftOrderedDictionary 1.0.0

SwiftOrderedDictionary 1.0.0

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Maintained by Julian Porter.

SwiftOrderedDictionary 1.0.0

  • By
  • julian porter

SwiftOrdered Dictionary

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API

SwiftOrderedDictionary offers a native Swift lightweight wrapper OrderedDictionary around the build in Swift Dictionary class, adding to it the capability to remember the order in which its key were first added.

The API for OrderedDictionary is essentially the same as that of Dictionary, so it should, in most cases, function as a simple drop-in replacement. The differences are that:

  • Variables like keys and values are now ordered, so they can be implemented as Arrays. This means that OrderedDictionary<K,V>.Keys == Array<K> and OrderedDictionary<K,V>.Values == Array<V>;, so there is no need to cast them to type Array as would be the case wityh an unordered dictionary.
  • Methods on Dictionary that do not work in an ordered context are dropped. Specifically, this means methods ands constructors that use a uniquing function. In particular, there are no merge methods.

The outline API of the type, written as a pseudo-protocol, is as follows. Methods perform as in a normal dictionary unless otherwise specified:

class OrderedDictionary<K,V> : Sequence where K : Hashable {
    
    typealias Element = (key: K,value : V)
    typealias Iterator = Array<Element>.Iterator
    typealias Keys = Array<K>
    typealias Values = Array<V>
    
    init() 
    init(minimumCapacity: Int) 
    init<S>(uniqueKeysWithValues: S) where S: Sequence, S.Element == (K,V) 
    
    var count : Int { get }
    var underestimatedCount: Int { get }
    var isEmpty : Bool { get }
    var capacity : Int { get }
    func reserveCapacity(_ : Int) 
    
    subscript( _ key : K) -> V? { get, set }
    subscript(_ key : K,default d: @autoclosure () -> V) -> V { get }
    
    var first : Element? { get }
    var randomElement : Element? { get }
    func randomElement<T>(using _: inout T) -> Element? where T : RandomNumberGenerator 
    
    var keys : Keys { get }
    var values : Values { get }
    
    /// method not in ordinary dictionary - returns key/value pairs as an ordered list
    var asArray : [Element] { get } 
    
    func updateValue(_ : V,forKey: K) -> V? )
    
    func removeAll() 
    public func removeValue(forKey : K) -> V? 
    
    // method not in ordinary dictionary - can now answer the question precisely by checking the list
    // of keys
    public func contains(_ : K) -> Bool 
    
}

Installation

ColourWheel is available through CocoaPods. To install it, simply add the following line to your Podfile:

pod 'OrderedDictionary'

Author

jdstmporter, [email protected].