Equatable sinks prototype #254
There are no files selected for viewing
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
| Original file line number | Diff line number | Diff line change |
|---|---|---|
|
|
@@ -18,16 +18,18 @@ import MarketWorkflowUI | |
| import Workflow | ||
|
|
||
| struct MainWorkflow: Workflow { | ||
| let canClose: Bool | ||
|
|
||
| enum Output { | ||
| case pushScreen | ||
| case presentScreen | ||
| case close | ||
| } | ||
|
|
||
| struct State { | ||
| var title: String | ||
| var isAllCaps: Bool | ||
| let trampoline = SinkTrampoline() | ||
|
There was a problem hiding this comment. This seems like the best/only way to create a persistent identity that we can use to implement |
||
|
|
||
| init(title: String) { | ||
| self.title = title | ||
|
|
@@ -39,53 +41,96 @@ struct MainWorkflow: Workflow { | |
| State(title: "New item") | ||
| } | ||
|
|
||
| typealias Rendering = MainScreen | ||
| typealias Action = MainScreen.Action | ||
|
|
||
| func render(state: State, context: RenderContext<Self>) -> Rendering { | ||
| let sink = state.trampoline.makeSink(of: Action.self, with: context) | ||
|
|
||
| return MainScreen( | ||
| title: state.title, | ||
| canClose: canClose, | ||
| allCapsToggleIsOn: state.isAllCaps, | ||
| allCapsToggleIsEnabled: !state.title.isEmpty, | ||
| sink: sink | ||
| ) | ||
| } | ||
| } | ||
|
|
||
| extension MainScreen.Action: WorkflowAction { | ||
| typealias WorkflowType = MainWorkflow | ||
|
|
||
| func apply(toState state: inout WorkflowType.State) -> WorkflowType.Output? { | ||
| switch self { | ||
| case .pushScreen: | ||
| return .pushScreen | ||
| case .presentScreen: | ||
| return .presentScreen | ||
| case .changeTitle(let newValue): | ||
| state.title = newValue | ||
| state.isAllCaps = newValue.isAllCaps | ||
| case .changeAllCaps(let isAllCaps): | ||
| state.isAllCaps = isAllCaps | ||
| state.title = isAllCaps ? state.title.uppercased() : state.title.lowercased() | ||
| case .close: | ||
| return .close | ||
| } | ||
| return nil | ||
| } | ||
| } | ||
|
|
||
| private extension String { | ||
| var isAllCaps: Bool { | ||
| allSatisfy { character in | ||
| character.isUppercase || !character.isCased | ||
| } | ||
| } | ||
| } | ||
|
|
||
| class SinkTrampoline: Equatable { | ||
| private var sinks: [ObjectIdentifier: Any] = [:] | ||
|
|
||
| func makeSink<Action, WorkflowType>( | ||
| of actionType: Action.Type, | ||
| with context: RenderContext<WorkflowType> | ||
| ) -> StableSink<Action> where Action: WorkflowAction, Action.WorkflowType == WorkflowType { | ||
| let sink = context.makeSink(of: actionType) | ||
|
|
||
| sinks[ObjectIdentifier(actionType)] = sink | ||
|
|
||
| return StableSink(trampoline: self) | ||
|
Comment on lines
+97
to
+101
There was a problem hiding this comment. I wonder if we could pass Maintaining Is the need for that safety greater when the Rendering holds |
||
| } | ||
|
|
||
| func bounce<Action>(action: Action) { | ||
| let sink = destination(for: Action.self) | ||
| sink.send(action) | ||
| } | ||
|
|
||
| private func destination<Action>(for actionType: Action.Type) -> Sink<Action> { | ||
| if let pipe = sinks[ObjectIdentifier(actionType)] { | ||
| return pipe as! Sink<Action> | ||
| } | ||
| fatalError("bad plumbing") | ||
| } | ||
|
|
||
| static func == (lhs: SinkTrampoline, rhs: SinkTrampoline) -> Bool { | ||
| lhs === rhs | ||
| } | ||
| } | ||
|
|
||
| struct StableSink<Action>: Equatable { | ||
| private var trampoline: SinkTrampoline | ||
|
|
||
| init(trampoline: SinkTrampoline) { | ||
| self.trampoline = trampoline | ||
| } | ||
|
|
||
| func send(_ action: Action) { | ||
| trampoline.bounce(action: action) | ||
| } | ||
|
|
||
| // sugar instead of writing { sink.send($0) } | ||
| func closure(_ action: Action) -> () -> Void { | ||
| { send(action) } | ||
| } | ||
| } | ||
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
There was a problem hiding this comment.
Choose a reason for hiding this comment
The reason will be displayed to describe this comment to others. Learn more.
Oh yeah, I think I've seen this go by in POS
There was a problem hiding this comment.
Choose a reason for hiding this comment
The reason will be displayed to describe this comment to others. Learn more.
I'm just now noticing that SwiftUI's
FocusStateis not Equatable. That makes it harder forViews to be Equatable, but I presume SwiftUI's internal comparison of non-Equatable View types handles it well.