Relax sendability / improve default main actor isolation compatibility

Sources/CasePaths/EnumReflection.swift

@@ -14,18 +14,17 @@ extension AnyCasePath {
   @available(macOS, deprecated: 9999, message: "Use a 'CasePathable' case key path, instead")
   @available(tvOS, deprecated: 9999, message: "Use a 'CasePathable' case key path, instead")
   @available(watchOS, deprecated: 9999, message: "Use a 'CasePathable' case key path, instead")
-  public init(unsafe embed: @escaping @Sendable (Value) -> Root) {
-    func open<Wrapped>(_: Wrapped.Type) -> @Sendable (Root) -> Value? {
-      optionalPromotedExtractHelp(unsafeBitCast(embed, to: (@Sendable (Value) -> Wrapped?).self))
-        as! @Sendable (Root) -> Value?
+  public init(unsafe embed: @escaping (Value) -> Root) {
+    func open<Wrapped>(_: Wrapped.Type) -> (Root) -> Value? {
+      optionalPromotedExtractHelp(unsafeBitCast(embed, to: ((Value) -> Wrapped?).self))
+        as! (Root) -> Value?
     }
-    @UncheckedSendable var embed = embed
     let extract =
       ((_Witness<Root>.self as? _AnyOptional.Type)?.wrappedType)
       .map { _openExistential($0, do: open) }
-      ?? extractHelp { [$embed] in $embed.wrappedValue($0) }
+      ?? extractHelp(embed)
     self.init(
-      embed: { [$embed] in $embed.wrappedValue($0) },
+      embed: embed,
       extract: extract
     )
   }
@@ -39,11 +38,11 @@ extension AnyCasePath {
   @available(tvOS, deprecated: 9999, message: "Use a 'CasePathable' case key path, instead")
   @available(watchOS, deprecated: 9999, message: "Use a 'CasePathable' case key path, instead")
   @_disfavoredOverload
-  public init(unsafe root: @autoclosure @escaping @Sendable () -> Root) where Value == Void {
-    func open<Wrapped>(_: Wrapped.Type) -> @Sendable (Root) -> Void? {
+  public init(unsafe root: @autoclosure @escaping () -> Root) where Value == Void {
+    func open<Wrapped>(_: Wrapped.Type) -> (Root) -> Void? {
       optionalPromotedExtractVoidHelp(
         unsafeBitCast(root, to: Wrapped?.self)
-      ) as! @Sendable (Root) -> Void?
+      ) as! (Root) -> Void?
     }
     let extract =
       ((_Witness<Root>.self as? _AnyOptional.Type)?.wrappedType)
@@ -61,8 +60,8 @@ private struct Cache: Sendable {
 }
 
 func extractHelp<Root, Value>(
-  _ embed: @escaping @Sendable (Value) -> Root
-) -> @Sendable (Root) -> Value? {
+  _ embed: @escaping (Value) -> Root
+) -> (Root) -> Value? {
   guard
     let metadata = EnumMetadata(Root.self),
     metadata.typeDescriptor.fieldDescriptor != nil
@@ -106,8 +105,8 @@ func extractHelp<Root, Value>(
 }
 
 func optionalPromotedExtractHelp<Root, Value>(
-  _ embed: @escaping @Sendable (Value) -> Root?
-) -> @Sendable (Root?) -> Value? {
+  _ embed: @escaping (Value) -> Root?
+) -> (Root?) -> Value? {
   guard Root.self != Value.self else { return { $0 as! Value? } }
   guard
     let metadata = EnumMetadata(Root.self),
@@ -138,7 +137,7 @@ func optionalPromotedExtractHelp<Root, Value>(
   }
 }
 
-func extractVoidHelp<Root>(_ root: Root) -> @Sendable (Root) -> Void? {
+func extractVoidHelp<Root>(_ root: Root) -> (Root) -> Void? {
   guard
     let metadata = EnumMetadata(Root.self),
     metadata.typeDescriptor.fieldDescriptor != nil
@@ -151,7 +150,7 @@ func extractVoidHelp<Root>(_ root: Root) -> @Sendable (Root) -> Void? {
   return { root in metadata.tag(of: root) == cachedTag ? () : nil }
 }
 
-func optionalPromotedExtractVoidHelp<Root>(_ root: Root?) -> @Sendable (Root?) -> Void? {
+func optionalPromotedExtractVoidHelp<Root>(_ root: Root?) -> (Root?) -> Void? {
   guard
     let root = root,
     let metadata = EnumMetadata(Root.self),

Sources/CasePaths/Internal/Deprecations.swift

@@ -81,15 +81,14 @@ extension Optional: _OptionalProtocol {
 extension AnyCasePath {
   @available(*, deprecated, message: "Use a 'CasePathable' case key path, instead")
   public init(_ embed: @escaping (Value) -> Root) {
-    @UncheckedSendable var embed = embed
-    self.init(unsafe: { [$embed] in $embed.wrappedValue($0) })
+    self.init(unsafe: embed)
   }
 }
 
 extension AnyCasePath where Value == Void {
   @available(*, deprecated, message: "Use a 'CasePathable' case key path, instead")
   @_disfavoredOverload
-  public init(_ root: @autoclosure @escaping @Sendable () -> Root) {
+  public init(_ root: @autoclosure @escaping () -> Root) {
     self.init(unsafe: root())
   }
 }
@@ -116,10 +115,9 @@ extension AnyCasePath {
 public prefix func / <Root, Value>(
   embed: @escaping (Value) -> Root
 ) -> AnyCasePath<Root, Value> {
-  @UncheckedSendable var embed = embed
-  return AnyCasePath(
-    embed: { [$embed] in $embed.wrappedValue($0) },
-    extract: { [$embed] in extractHelp { $embed.wrappedValue($0) }($0) }
+  AnyCasePath(
+    embed: embed,
+    extract: { extractHelp(embed)($0) }
   )
 }
 
@@ -128,27 +126,26 @@ public prefix func / <Root, Value>(
 public prefix func / <Root, Value>(
   embed: @escaping (Value) -> Root?
 ) -> AnyCasePath<Root?, Value> {
-  @UncheckedSendable var embed = embed
-  return AnyCasePath(
-    embed: { [$embed] in $embed.wrappedValue($0) },
-    extract: optionalPromotedExtractHelp { [$embed] in $embed.wrappedValue($0) }
+  AnyCasePath(
+    embed: embed,
+    extract: optionalPromotedExtractHelp(embed)
   )
 }
 
 @_documentation(visibility: internal)
 @available(*, deprecated, message: "Use a 'CasePathable' case key path, instead")
 public prefix func / <Root>(
-  root: @autoclosure @escaping @Sendable () -> Root
+  root: @autoclosure @escaping () -> Root
 ) -> AnyCasePath<Root, Void> {
-  .init(embed: root, extract: extractVoidHelp(root()))
+  AnyCasePath(embed: root, extract: extractVoidHelp(root()))
 }
 
 @_documentation(visibility: internal)
 @available(*, deprecated, message: "Use a 'CasePathable' case key path, instead")
 public prefix func / <Root>(
-  root: @autoclosure @escaping @Sendable () -> Root?
+  root: @autoclosure @escaping () -> Root?
 ) -> AnyCasePath<Root?, Void> {
-  .init(embed: root, extract: optionalPromotedExtractVoidHelp(root()))
+  AnyCasePath(embed: root, extract: optionalPromotedExtractVoidHelp(root()))
 }
 
 @_documentation(visibility: internal)
@@ -195,7 +192,7 @@ public prefix func / <Root, Value>(
   *, deprecated, message: "Use a 'CasePathable' case property via dynamic member lookup, instead"
 )
 public prefix func / <Root>(
-  root: @autoclosure @escaping @Sendable () -> Root
+  root: @autoclosure @escaping () -> Root
 ) -> (Root) -> Void? {
   (/root).extract(from:)
 }
@@ -206,7 +203,7 @@ public prefix func / <Root>(
   *, deprecated, message: "Use a 'CasePathable' case property via dynamic member lookup, instead"
 )
 public prefix func / <Root>(
-  root: @autoclosure @escaping @Sendable () -> Root
+  root: @autoclosure @escaping () -> Root
 ) -> (Root?) -> Void? {
   (/root).extract(from:)
 }
@@ -315,8 +312,8 @@ extension AnyCasePath where Root == Void {
   /// - Parameter value: A constant value.
   /// - Returns: A case path from `()` to `value`.
   @available(*, deprecated)
-  public static func constant(_ value: @autoclosure @escaping @Sendable () -> Value) -> Self {
-    .init(
+  public static func constant(_ value: @autoclosure @escaping () -> Value) -> Self {
+    AnyCasePath(
       embed: { _ in () },
       extract: { .some(value()) }
     )
@@ -328,8 +325,8 @@ extension AnyCasePath where Value == Never {
   /// uninhabited `Never` type.
   @available(*, deprecated)
   public static var never: Self {
-    @Sendable func absurd<A>(_ never: Never) -> A {}
-    return .init(
+    func absurd<A>(_ never: Never) -> A {}
+    return AnyCasePath(
       embed: absurd,
       extract: { _ in nil }
     )
@@ -370,7 +367,7 @@ extension AnyCasePath {
   /// - Parameter embed: An enum case initializer.
   /// - Returns: A case path that extracts associated values from enum cases.
   @available(*, deprecated, message: "Use a 'CasePathable' case key path, instead")
-  public static func `case`(_ embed: @escaping @Sendable (Value) -> Root) -> Self {
+  public static func `case`(_ embed: @escaping (Value) -> Root) -> Self {
     self.init(
       embed: embed,
       extract: { CasePaths.extract(embed)($0) }
@@ -387,7 +384,7 @@ extension AnyCasePath where Value == Void {
   /// - Parameter value: An enum case with no associated values.
   /// - Returns: A case path that extracts `()` if the case matches, otherwise `nil`.
   @available(*, deprecated, message: "Use a 'CasePathable' case key path, instead")
-  public static func `case`(_ value: @autoclosure @escaping @Sendable () -> Root) -> Self {
+  public static func `case`(_ value: @autoclosure @escaping () -> Root) -> Self {
     Self(
       embed: value,
       extract: extractVoidHelp(value())
@@ -413,7 +410,7 @@ extension AnyCasePath where Value == Void {
 ///   otherwise `nil`.
 @available(*, deprecated, message: "Use a '@CasePathable' case property, instead")
 public func extract<Root, Value>(
-  case embed: @escaping @Sendable (Value) -> Root,
+  case embed: @escaping (Value) -> Root,
   from root: Root
 ) -> Value? {
   CasePaths.extract(embed)(root)
@@ -437,7 +434,7 @@ public func extract<Root, Value>(
 ///   otherwise `nil`.
 @available(*, deprecated, message: "Use a '@CasePathable' case property, instead")
 public func extract<Root, Value>(
-  case embed: @escaping @Sendable (Value) -> Root?,
+  case embed: @escaping (Value) -> Root?,
   from root: Root?
 ) -> Value? {
   CasePaths.extract(embed)(root)
@@ -460,7 +457,7 @@ public func extract<Root, Value>(
 /// - Parameter embed: An enum case initializer.
 /// - Returns: A function that can attempt to extract associated values from an enum.
 @available(*, deprecated, message: "Use a '@CasePathable' case property, instead")
-public func extract<Root, Value>(_ embed: @escaping @Sendable (Value) -> Root) -> (Root) -> Value? {
+public func extract<Root, Value>(_ embed: @escaping (Value) -> Root) -> (Root) -> Value? {
   extractHelp(embed)
 }
 
@@ -482,7 +479,7 @@ public func extract<Root, Value>(_ embed: @escaping @Sendable (Value) -> Root) -
 /// - Returns: A function that can attempt to extract associated values from an enum.
 @available(*, deprecated, message: "Use a '@CasePathable' case property, instead")
 public func extract<Root, Value>(
-  _ embed: @escaping @Sendable (Value) -> Root?
-) -> @Sendable (Root?) -> Value? {
+  _ embed: @escaping (Value) -> Root?
+) -> (Root?) -> Value? {
   optionalPromotedExtractHelp(embed)
 }

Sources/CasePaths/Macros.swift

@@ -26,7 +26,14 @@
 /// \UserAction.Cases.settings  // CasePath<UserAction, SettingsAction>
 /// ```
 @attached(extension, conformances: CasePathable, CasePathIterable)
-@attached(member, names: named(AllCasePaths), named(allCasePaths), named(_$Element))
+@attached(
+  member,
+  conformances: CasePathable,
+  CasePathIterable,
+  names: named(AllCasePaths),
+  named(allCasePaths),
+  named(_$Element)
+)
 public macro CasePathable() =
   #externalMacro(
     module: "CasePathsMacros", type: "CasePathableMacro"

Sources/CasePathsCore/AnyCasePath.swift

@@ -6,36 +6,23 @@ import Foundation
 /// This type defines key path-like semantics for enum cases, and is used to derive ``CaseKeyPath``s
 /// from types that conform to ``CasePathable``.
 @dynamicMemberLookup
-public struct AnyCasePath<Root, Value>: Sendable {
-  private let _embed: @Sendable (Value) -> Root
-  private let _extract: @Sendable (Root) -> Value?
+public struct AnyCasePath<Root, Value> {
+  private let _embed: (Value) -> Root
+  private let _extract: (Root) -> Value?
 
   /// Creates a type-erased case path from a pair of functions.
   ///
   /// - Parameters:
   ///   - embed: A function that always succeeds in embedding a value in a root.
   ///   - extract: A function that can optionally fail in extracting a value from a root.
   public init(
-    embed: @escaping @Sendable (Value) -> Root,
-    extract: @escaping @Sendable (Root) -> Value?
+    embed: @escaping (Value) -> Root,
+    extract: @escaping (Root) -> Value?
   ) {
     self._embed = embed
     self._extract = extract
   }
 
-  public static func _$embed(
-    _ embed: @escaping (Value) -> Root,
-    extract: @escaping @Sendable (Root) -> Value?
-  ) -> Self {
-    #if swift(>=5.10)
-      nonisolated(unsafe) let embed = embed
-      return Self(embed: { embed($0) }, extract: extract)
-    #else
-      @UncheckedSendable var embed = embed
-      return Self(embed: { [$embed] in $embed.wrappedValue($0) }, extract: extract)
-    #endif
-  }
-
   /// Returns a root by embedding a value.
   ///
   /// - Parameter value: A value to embed.

Sources/CasePathsCore/CasePathable.swift

@@ -46,18 +46,18 @@ public protocol CasePathable {
 /// associated value types.
 @_documentation(visibility: internal)
 @dynamicMemberLookup
-public struct Case<Value>: Sendable {
-  fileprivate let _embed: @Sendable (Value) -> Any
-  fileprivate let _extract: @Sendable (Any) -> Value?
+public struct Case<Value> {
+  fileprivate let _embed: (Value) -> Any
+  fileprivate let _extract: (Any) -> Value?
 }
 
 extension Case {
   public init<Root>(
-    embed: @escaping @Sendable (Value) -> Root,
-    extract: @escaping @Sendable (Root) -> Value?
+    embed: @escaping (Value) -> Root,
+    extract: @escaping (Root) -> Value?
   ) {
     self._embed = embed
-    self._extract = { @Sendable in ($0 as? Root).flatMap(extract) }
+    self._extract = { ($0 as? Root).flatMap(extract) }
   }
 
   public init() {
@@ -72,14 +72,9 @@ extension Case {
     dynamicMember keyPath: KeyPath<Value.AllCasePaths, AnyCasePath<Value, AppendedValue>>
   ) -> Case<AppendedValue>
   where Value: CasePathable {
-    let keyPath = keyPath.unsafeSendable()
-    return Case<AppendedValue>(
-      embed: {
-        _embed(Value.allCasePaths[keyPath: keyPath].embed($0))
-      },
-      extract: {
-        _extract(from: $0).flatMap(Value.allCasePaths[keyPath: keyPath].extract)
-      }
+    Case<AppendedValue>(
+      embed: { _embed(Value.allCasePaths[keyPath: keyPath].embed($0)) },
+      extract: { _extract(from: $0).flatMap(Value.allCasePaths[keyPath: keyPath].extract) }
     )
   }
 
@@ -516,16 +511,9 @@ extension AnyCasePath where Value: CasePathable {
   public subscript<AppendedValue>(
     dynamicMember keyPath: KeyPath<Value.AllCasePaths, AnyCasePath<Value, AppendedValue>>
   ) -> AnyCasePath<Root, AppendedValue> {
-    let keyPath = keyPath.unsafeSendable()
-    return AnyCasePath<Root, AppendedValue>(
-      embed: {
-        embed(Value.allCasePaths[keyPath: keyPath].embed($0))
-      },
-      extract: {
-        extract(from: $0).flatMap(
-          Value.allCasePaths[keyPath: keyPath].extract(from:)
-        )
-      }
+    AnyCasePath<Root, AppendedValue>(
+      embed: { embed(Value.allCasePaths[keyPath: keyPath].embed($0)) },
+      extract: { extract(from: $0).flatMap(Value.allCasePaths[keyPath: keyPath].extract(from:)) }
     )
   }
 }