Tuples.swift

Generic Tuple types for Swift

Why?

Swift doesn't support generics for tuples. They can't be properly used in the where clauses.

This library provides set of tuple-like structs and helper protocols to fix this.

Getting started

Installation

Package Manager

Add the following dependency to your Package.swift:

.package(url: "https://github.com/tesseract-one/Tuples.swift.git", from: "0.1.0")

Run swift build and build your app.

CocoaPods

Add the following to your Podfile:

pod 'Tuples', '~> 0.1.0'

Then run pod install

Examples

Accept tuple as generic parameter

func accept_tuple<T>(tuple: T.STuple) where T: SomeTuple2, T.T1: StringProtocol, T.T2: UnsignedInteger {
    // tuple is (StringProtocol, UnsignedInteger)
    // tuple struct can be created
    let tupleStruct = T(tuple)
}

Common constructor method

// Will create Tuple4<Int, String, Double, Array<Int>> instance
let tupleStruct = TL((1, "string", 2.0, [1, 2, 3]))

Tuple from array

 // Tuple3<Int, Int, Int> returned but typed as OneTypeTuple<Int>
let tuple: OneTypeTuple<Int> = TL([1, 2, 3])

Codable

Tuples can be encoded / decoded as arrays.

let json = try! JSONEncoder().encode(TL((1, "string", Data())))
let tuple = try JSONDecodder().decode(Tuple3<Int, String, Data>.self, from: json).tuple

List tuples

All tuples with 1+ elements supports ListTuple protocol which allows to get first and last elements from the tuple and also suffix and prefix tuples without this elements.

public protocol ListTuple: SomeTuple {
    associatedtype First
    associatedtype Last
    associatedtype DroppedFirst: SomeTuple
    associatedtype DroppedLast: SomeTuple
    
    init(first: DroppedLast, last: Last)
    init(first: First, last: DroppedFirst)
    
    var first: First { get }
    var last: Last { get }
    var dropLast: DroppedLast { get }
    var dropFirst: DroppedFirst { get }
}

Usage examples can be found in the Codable and CustomStringConvertible implementations

Author

• Tesseract Systems, Inc. (@tesseract_one)

License

Tuples.swift is available under the Apache 2.0 license. See the LICENSE file for more information.