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Merge pull request #11 from ReactiveCocoa/anders/swiftui
@LoopBinding and @EnvironmentLoop for SwiftUI.
2 parents a013754 + 2a29ae7 commit 49404fc

14 files changed

+413
-1
lines changed

‎Example/Root/RootView.swift

+4
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@@ -20,6 +20,10 @@ struct RootView: View {
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CardNavigationLink(label: "Unified Store + UIKit", color: .blue) {
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UnifiedStoreUIKitHomeView()
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}
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CardNavigationLink(label: "SwiftUI: Basic Binding", color: .orange) {
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SwiftUIBasicBindingHomeView()
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}
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}
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.navigationBarTitle("Loop Examples")
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.navigationBarHidden(true)

‎Example/SwiftUIBasicBindingExample/EnvironmentLoopExampleView.swift

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@@ -0,0 +1,32 @@
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import SwiftUI
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import Loop
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struct EnvironmentLoopExampleView: View {
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let loop: Loop<Int, Int>
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init(loop: Loop<Int, Int>) {
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self.loop = loop
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}
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var body: some View {
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EnvironmentLoopContentView()
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.environmentLoop(self.loop)
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.navigationBarTitle("@EnvironmentLoop")
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}
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}
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private struct EnvironmentLoopContentView: View {
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@EnvironmentLoop<Int, Int> var state: Int
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var body: some View {
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SimpleCounterView(binding: $state)
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}
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}
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struct EnvironmentLoopExampleView_Previews: PreviewProvider {
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static var previews: some View {
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NavigationView {
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EnvironmentLoopExampleView(loop: simpleCounterStore)
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}
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}
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}

‎Example/SwiftUIBasicBindingExample/LoopBindingExampleView.swift

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@@ -0,0 +1,23 @@
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import SwiftUI
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import Loop
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struct LoopBindingExampleView: View {
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@LoopBinding<Int, Int> var state: Int
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init(state: LoopBinding<Int, Int>) {
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_state = state
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}
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var body: some View {
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SimpleCounterView(binding: $state)
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.navigationBarTitle("@LoopBinding")
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}
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}
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struct LoopBindingExampleView_Previews: PreviewProvider {
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static var previews: some View {
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NavigationView {
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LoopBindingExampleView(state: simpleCounterStore.binding)
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}
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}
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}

‎Example/SwiftUIBasicBindingExample/SimpleCounterStore.swift

+3
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@@ -0,0 +1,3 @@
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import Loop
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let simpleCounterStore = Loop(initial: 0, reducer: { state, event in state += event }, feedbacks: [])

‎Example/SwiftUIBasicBindingExample/SimpleCounterView.swift

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@@ -0,0 +1,35 @@
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import SwiftUI
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import Loop
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struct SimpleCounterView: View {
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@LoopBinding<Int, Int> var state: Int
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init(binding: LoopBinding<Int, Int>) {
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_state = binding
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}
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var body: some View {
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VStack {
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Spacer()
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.layoutPriority(1.0)
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Button(
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action: { self.$state.send(-1) },
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label: { Image(systemName: "minus.circle") }
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)
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.padding()
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Text("\(self.state)")
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.font(.system(.largeTitle, design: .monospaced))
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Button(
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action: { self.$state.send(1) },
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label: { Image(systemName: "plus.circle") }
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)
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.padding()
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Spacer()
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.layoutPriority(1.0)
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}
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}
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}

‎Example/SwiftUIBasicBindingExample/SwiftUIBasicBindingHomeView.swift

+16
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@@ -0,0 +1,16 @@
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import SwiftUI
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import Loop
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struct SwiftUIBasicBindingHomeView: View {
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var body: some View {
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ScrollView {
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CardNavigationLink(label: "@LoopBinding", color: .orange) {
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LoopBindingExampleView(state: simpleCounterStore.binding)
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}
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CardNavigationLink(label: "@EnvironmentLoop", color: .orange) {
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EnvironmentLoopExampleView(loop: simpleCounterStore)
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}
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}
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}
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}

‎Loop.xcodeproj/project.pbxproj

+76
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‎Loop/LoopBox.swift

+13
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@@ -9,6 +9,11 @@ internal class ScopedLoopBox<RootState, RootEvent, ScopedState, ScopedEvent>: Lo
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root.lifetime
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}
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/// Loop Internal SPI
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override var _current: ScopedState {
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root._current[keyPath: value]
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}
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private let root: LoopBoxBase<RootState, RootEvent>
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private let value: KeyPath<RootState, ScopedState>
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private let eventTransform: (ScopedEvent) -> RootEvent
@@ -44,6 +49,11 @@ internal class RootLoopBox<State, Event>: LoopBoxBase<State, Event> {
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_lifetime
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}
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/// Loop Internal SPI
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override var _current: State {
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floodgate.withValue { state, _ in state }
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}
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let floodgate: Floodgate<State, Event>
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private let _lifetime: Lifetime
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private let token: Lifetime.Token
@@ -89,6 +99,9 @@ internal class RootLoopBox<State, Event>: LoopBoxBase<State, Event> {
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}
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91101
internal class LoopBoxBase<State, Event> {
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/// Loop Internal SPI
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var _current: State { subclassMustImplement() }
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var lifetime: Lifetime { subclassMustImplement() }
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var producer: SignalProducer<State, Never> { subclassMustImplement() }
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‎Loop/Public/Loop.swift

+6-1
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@@ -19,7 +19,12 @@ public final class Loop<State, Event> {
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}
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}
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private let box: LoopBoxBase<State, Event>
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@available(macOS 10.15, iOS 13.0, tvOS 13.0, watchOS 6.0, *)
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public var binding: LoopBinding<State, Event> {
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LoopBinding(self)
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}
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internal let box: LoopBoxBase<State, Event>
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private init(box: LoopBoxBase<State, Event>) {
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self.box = box

‎Loop/Public/SwiftUI/EnvironmentLoop.swift

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#if canImport(SwiftUI) && canImport(Combine)
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import SwiftUI
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import Combine
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import ReactiveSwift
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@available(macOS 10.15, iOS 13.0, tvOS 13.0, watchOS 6.0, *)
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@propertyWrapper
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public struct EnvironmentLoop<State, Event>: DynamicProperty {
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@Environment(\.loops[LoopType(Loop<State, Event>.self)])
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var erasedLoop: AnyObject?
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@ObservedObject
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private var subscription: SwiftUIHotSwappableSubscription<State, Event>
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@inlinable
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public var wrappedValue: State {
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acknowledgedState
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}
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public var projectedValue: LoopBinding<State, Event> {
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guard let loop = erasedLoop as! Loop<State, Event>? else {
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fatalError("Scoped bindings can only be created inside the view body.")
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}
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return LoopBinding(loop)
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}
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@usableFromInline
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internal var acknowledgedState: State!
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public init() {
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self.subscription = SwiftUIHotSwappableSubscription()
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}
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public mutating func update() {
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guard let loop = erasedLoop as! Loop<State, Event>? else {
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fatalError("Expect parent view to inject a `Loop<\(State.self), \(Event.self)>` through `View.environmentLoop(_:)`. Found none.")
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}
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acknowledgedState = subscription.currentState(in: loop)
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}
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}
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#endif

‎Loop/Public/SwiftUI/EnvironmentValues.swift

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@@ -0,0 +1,43 @@
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#if canImport(SwiftUI)
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import SwiftUI
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@available(macOS 10.15, iOS 13.0, tvOS 13.0, watchOS 6.0, *)
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extension View {
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@inlinable
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public func environmentLoop<State, Event>(_ loop: Loop<State, Event>) -> some View {
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let typeId = LoopType(type(of: loop))
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return transformEnvironment(\.loops) { loops in
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loops[typeId] = loop
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}
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}
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}
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@available(macOS 10.15, iOS 13.0, tvOS 13.0, watchOS 6.0, *)
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extension EnvironmentValues {
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@usableFromInline
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internal var loops: [LoopType: AnyObject] {
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get { self[LoopEnvironmentKey.self] }
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set { self[LoopEnvironmentKey.self] = newValue }
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}
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}
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@available(macOS 10.15, iOS 13.0, tvOS 13.0, watchOS 6.0, *)
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internal enum LoopEnvironmentKey: EnvironmentKey {
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static var defaultValue: [LoopType: AnyObject] {
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return [:]
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}
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}
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@usableFromInline
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struct LoopType: Hashable {
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let id: ObjectIdentifier
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@usableFromInline
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init(_ type: Any.Type) {
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id = ObjectIdentifier(type)
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}
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}
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#endif

‎Loop/Public/SwiftUI/LoopBinding.swift

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#if canImport(SwiftUI) && canImport(Combine)
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import SwiftUI
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import Combine
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import ReactiveSwift
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@available(macOS 10.15, iOS 13.0, tvOS 13.0, watchOS 6.0, *)
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@propertyWrapper
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public struct LoopBinding<State, Event>: DynamicProperty {
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@ObservedObject
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private var subscription: SwiftUISubscription<State, Event>
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private let loop: Loop<State, Event>
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@inlinable
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public var wrappedValue: State {
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acknowledgedState
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}
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public var projectedValue: LoopBinding<State, Event> {
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self
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}
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@usableFromInline
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internal var acknowledgedState: State
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public init(_ loop: Loop<State, Event>) {
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// The subscription can be copied without restrictions.
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let subscription = SwiftUISubscription(loop: loop)
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self.subscription = subscription
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self.acknowledgedState = subscription.latestValue
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self.loop = loop
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}
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public mutating func update() {
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// Move latest value from the subscription only when SwiftUI has requested an update.
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acknowledgedState = subscription.latestValue
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}
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public func scoped<ScopedState, ScopedEvent>(
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to value: KeyPath<State, ScopedState>,
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event: @escaping (ScopedEvent) -> Event
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) -> LoopBinding<ScopedState, ScopedEvent> {
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LoopBinding<ScopedState, ScopedEvent>(loop.scoped(to: value, event: event))
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}
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public func send(_ event: Event) {
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loop.send(event)
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}
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}
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#endif

‎Loop/Public/SwiftUI/SwiftUIHotSwappableSubscription.swift

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#if canImport(Combine)
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import Combine
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import ReactiveSwift
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@available(macOS 10.15, iOS 13.0, tvOS 13.0, watchOS 6.0, *)
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internal final class SwiftUIHotSwappableSubscription<State, Event>: ObservableObject {
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@Published private var latestValue: State!
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private weak var attachedLoop: Loop<State, Event>?
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private var disposable: Disposable?
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init() {}
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deinit {
16+
disposable?.dispose()
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}
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func currentState(in loop: Loop<State, Event>) -> State {
20+
if attachedLoop !== loop {
21+
disposable?.dispose()
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latestValue = loop.box._current
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disposable = loop.producer
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.observe(on: UIScheduler())
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.startWithValues { [weak self] state in
28+
guard let self = self else { return }
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self.latestValue = state
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}
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}
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return latestValue
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}
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}
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#endif

‎Loop/Public/SwiftUI/SwiftUISubscription.swift

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#if canImport(Combine)
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import Combine
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import ReactiveSwift
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@available(macOS 10.15, iOS 13.0, tvOS 13.0, watchOS 6.0, *)
7+
internal final class SwiftUISubscription<State, Event>: ObservableObject {
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@Published var latestValue: State
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private var disposable: Disposable?
11+
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init(loop: Loop<State, Event>) {
13+
latestValue = loop.box._current
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disposable = loop.producer
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.observe(on: UIScheduler())
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.startWithValues { [weak self] state in
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guard let self = self else { return }
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self.latestValue = state
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}
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}
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deinit {
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disposable?.dispose()
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}
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}
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#endif

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