By the moment this is a POC of the swift macros to be tested on the playtomic-iOS project.
Link to iOS project: Playtomic iOS Project
Here you can find a notion document related with this project: WIP Macros
A macro that produces both a value and a string containing the source code that generated the value. For example,
#stringify(x + y)
// produces a tuple (x + y, "x + y"). Creates a non-optional URL from a static string. The string is checked to be valid during compile time.
#URL("https://playtomic.io")
// produces a URL(string: "https://playtomic.io")!Displays compile time warning
#warning("This macro generates a message")
// produces a warning at compile time with following message: "This macro generates a message"Converts callbacks to async code
@addAsyncMacro
func sportsSelector(sports: [String], callback: @escaping (String) -> Void) -> Void {
callback(sports.joined(separator: ", "))
}
// Generates:
func sportsSelector(sports: [String]) async -> String {
await withCheckedContinuation { continuation in
sportsSelector(sports: sports) { returnValue in
continuation.resume(returning: returnValue)
}
}
}@Copyable is a Swift syntax macro that generates a copy function for a class or struct, similar to the copy function in Android. This function allows you to create a copy of an instance with modified properties.
@Copyable
struct ExampleViewState {
let title: String
let count: Int?
}
// Generates:
struct ExampleViewState {
let title: String
let count: Int?
func copy(
title: String? = nil,
count: Nullable<Int> = .none
) -> ExampleViewState {
return ExampleViewState(
title: title ?? self.title,
count: count ?? self.count
)
}
}Adds initializer to the type, very useful for classes that doesnt implement init by themselve.
@AddInit
class Object: CustomStringConvertible {
let id: Int
private let name: String
var description: String {
"id: \(id), name: \(name)"
}
}
// Generates:
class Object: CustomStringConvertible {
let id: Int
private let name: String
var description: String {
"id: \(id), name: \(name)"
}
init(id: Int, name: String) {
self.id = id
self.name = name
}
}Implements boolean computed properties per each enum case to provide case detection.
@caseDetection
enum ProfileViewState {
case loading
case loaded(userName: String)
}
// Generates:
enum ProfileViewState {
case loading
case loaded(userName: String)
var isLoading: Bool {
if case .loading = self {
return true
}
return false
}
var isLoaded: Bool {
if case .loaded = self {
return true
}
return false
}
}Apply the specified attribute to each of the stored properties within the type or member to which the macro is attached. The string can be any attribute (without the @).
@wrapStoredProperties(#"available(*, deprecated, message: "hands off my data")"#)
struct OldStorage {
var x: Int
}
// Generates:
struct OldStorage {
@available(*, deprecated, message: "hands off my data")
var x: Int
}Implements UserDefaults.standard setter and getter methods over each property attached with @storedAccess.
struct User {
@storedAccess(defaultValue: "")
var userId: String
}
// Generates:
struct User {
var userId: String {
get {
if UserDefaults.standard.value(forKey: "userId") == nil {
return ""
}
return UserDefaults.standard.string(forKey: "userId") ?? ""
}
set {
UserDefaults.standard.setValue(newValue, forKey: "userId")
}
}
}Creates an extension that conforms to Equatable protocol.
@equatable
struct MatchTeam {
let id: String
let playerd: [String]
}
// Generates:
struct MatchTeam {
let id: String
let playerd: [String]
}
extension MatchTeam: Equatable { } Generates sealed class boiler plate from attached type
protocol ViewAction { }
@Sealed
public class LevelUpgradeViewAction: ViewAction {
private init() {}
public protocol NavigationAction {
var navigationActionType: NavigationActionSealedType { get }
}
public protocol EventAction {
var eventActionType: EventActionSealedType { get }
}
public protocol ObserverAction {
var observerActionType: ObserverActionSealedType { get }
}
@AddInit
public class OnAppear: LevelUpgradeViewAction, EventAction, ObserverAction { }
@AddInit
public class Upgrade: LevelUpgradeViewAction { }
@AddInit
public class OnUpgradeStarted: LevelUpgradeViewAction, EventAction {
let from: Decimal
let to: Decimal
}
@AddInit
public class OnUpgradeSuccess: LevelUpgradeViewAction, NavigationAction {
let from: Decimal
let to: Decimal
}
@AddInit
public class OnUpgradeError: LevelUpgradeViewAction, NavigationAction {
let error: String
}
@AddInit
public class OnUpgradeSkipped: LevelUpgradeViewAction, NavigationAction, EventAction { }
}
// Generates:
public extension LevelUpgradeViewAction {
enum SealedType {
case OnAppear
case Upgrade
case OnUpgradeStarted(LevelUpgradeViewAction.OnUpgradeStarted)
case OnUpgradeSuccess(LevelUpgradeViewAction.OnUpgradeSuccess)
case OnUpgradeError(LevelUpgradeViewAction.OnUpgradeError)
case OnUpgradeSkipped
}
enum EventActionSealedType {
case OnAppear
case OnUpgradeStarted(LevelUpgradeViewAction.OnUpgradeStarted)
case OnUpgradeSkipped
}
enum ObserverActionSealedType {
case OnAppear
}
enum NavigationActionSealedType {
case OnUpgradeSuccess(LevelUpgradeViewAction.OnUpgradeSuccess)
case OnUpgradeError(LevelUpgradeViewAction.OnUpgradeError)
case OnUpgradeSkipped
}
}
public extension LevelUpgradeViewAction {
var type: LevelUpgradeViewAction.SealedType {
switch self {
case is LevelUpgradeViewAction.OnAppear:
LevelUpgradeViewAction.SealedType.OnAppear
case is LevelUpgradeViewAction.Upgrade:
LevelUpgradeViewAction.SealedType.Upgrade
case is LevelUpgradeViewAction.OnUpgradeStarted:
LevelUpgradeViewAction.SealedType.OnUpgradeStarted(self as! LevelUpgradeViewAction.OnUpgradeStarted)
case is LevelUpgradeViewAction.OnUpgradeSuccess:
LevelUpgradeViewAction.SealedType.OnUpgradeSuccess(self as! LevelUpgradeViewAction.OnUpgradeSuccess)
case is LevelUpgradeViewAction.OnUpgradeError:
LevelUpgradeViewAction.SealedType.OnUpgradeError(self as! LevelUpgradeViewAction.OnUpgradeError)
case is LevelUpgradeViewAction.OnUpgradeSkipped:
LevelUpgradeViewAction.SealedType.OnUpgradeSkipped
default:
fatalError("Unknown type \(self) in LevelUpgradeViewAction.SealedType")
}
}
}
public extension LevelUpgradeViewAction.EventAction {
var eventActionType: LevelUpgradeViewAction.EventActionSealedType {
switch self {
case is LevelUpgradeViewAction.OnAppear:
LevelUpgradeViewAction.EventActionSealedType.OnAppear
case is LevelUpgradeViewAction.OnUpgradeStarted:
LevelUpgradeViewAction.EventActionSealedType.OnUpgradeStarted(self as! LevelUpgradeViewAction.OnUpgradeStarted)
case is LevelUpgradeViewAction.OnUpgradeSkipped:
LevelUpgradeViewAction.EventActionSealedType.OnUpgradeSkipped
default:
fatalError("Unknown type \(self) in LevelUpgradeViewAction.EventActionSealedType")
}
}
}
public extension LevelUpgradeViewAction.ObserverAction {
var observerActionType: LevelUpgradeViewAction.ObserverActionSealedType {
switch self {
case is LevelUpgradeViewAction.OnAppear:
LevelUpgradeViewAction.ObserverActionSealedType.OnAppear
default:
fatalError("Unknown type \(self) in LevelUpgradeViewAction.ObserverActionSealedType")
}
}
}
public extension LevelUpgradeViewAction.NavigationAction {
var navigationActionType: LevelUpgradeViewAction.NavigationActionSealedType {
switch self {
case is LevelUpgradeViewAction.OnUpgradeSuccess:
LevelUpgradeViewAction.NavigationActionSealedType.OnUpgradeSuccess(self as! LevelUpgradeViewAction.OnUpgradeSuccess)
case is LevelUpgradeViewAction.OnUpgradeError:
LevelUpgradeViewAction.NavigationActionSealedType.OnUpgradeError(self as! LevelUpgradeViewAction.OnUpgradeError)
case is LevelUpgradeViewAction.OnUpgradeSkipped:
LevelUpgradeViewAction.NavigationActionSealedType.OnUpgradeSkipped
default:
fatalError("Unknown type \(self) in LevelUpgradeViewAction.NavigationActionSealedType")
}
}
}