Swift Language Support: Drop <5.9, Add 6.0 (#73)

* wip

* wip

.github/workflows/ci.yml

@@ -10,20 +10,20 @@ on:
 
 jobs:
   build:
-    name: MacOS
-    runs-on: macos-13
+    name: macOS
+    runs-on: macos-14
     steps:
     - uses: actions/checkout@v4
-    - name: Select Xcode 15.2
-      run: sudo xcode-select -s /Applications/Xcode_15.2.app
+    - name: Select Xcode 15.4
+      run: sudo xcode-select -s /Applications/Xcode_15.4.app
     - name: Run tests
       run: make test-swift
 
   ubuntu:
     strategy:
       matrix:
         swift:
-          - '5.9'
+          - '5.10'
     name: Ubuntu (Swift ${{ matrix.swift }})
     runs-on: ubuntu-latest
     container: swift:${{ matrix.swift }}
@@ -35,7 +35,7 @@ jobs:
       run: swift test -c release --parallel
 
   windows:
-    name: Windows (Swift ${{ matrix.swfit }}, ${{ matrix.config }})
+    name: Windows (Swift ${{ matrix.swift }}, ${{ matrix.config }})
     strategy:
       matrix:
         os: [windows-latest]
@@ -45,8 +45,8 @@ jobs:
     steps:
       - uses: compnerd/gha-setup-swift@main
         with:
-          branch: swift-5.9.1-release
-          tag: 5.9.1-RELEASE
+          branch: swift-5.10-release
+          tag: 5.10-RELEASE
       - uses: actions/checkout@v4
       - name: Build
         run: swift build -c ${{ matrix.config }}

Package.swift

@@ -1,4 +1,4 @@
-// swift-tools-version:5.6
+// swift-tools-version: 5.9
 
 import PackageDescription
 
@@ -35,6 +35,13 @@ let package = Package(
   ]
 )
 
+for target in package.targets {
+  target.swiftSettings = target.swiftSettings ?? []
+  target.swiftSettings!.append(contentsOf: [
+    .enableExperimentalFeature("StrictConcurrency")
+  ])
+}
+
 #if !os(Windows)
   // DocC needs to be ported to Windows
   // https://github.com/thebrowsercompany/swift-build/issues/39

Package@swift-6.0.swift

@@ -0,0 +1,45 @@
+// swift-tools-version: 6.0
+
+import PackageDescription
+
+let package = Package(
+  name: "swift-identified-collections",
+  products: [
+    .library(
+      name: "IdentifiedCollections",
+      targets: ["IdentifiedCollections"]
+    )
+  ],
+  dependencies: [
+    .package(url: "https://github.com/apple/swift-collections", from: "1.0.2"),
+    .package(url: "https://github.com/apple/swift-collections-benchmark", from: "0.0.2"),
+  ],
+  targets: [
+    .target(
+      name: "IdentifiedCollections",
+      dependencies: [
+        .product(name: "OrderedCollections", package: "swift-collections")
+      ]
+    ),
+    .testTarget(
+      name: "IdentifiedCollectionsTests",
+      dependencies: ["IdentifiedCollections"]
+    ),
+    .executableTarget(
+      name: "swift-identified-collections-benchmark",
+      dependencies: [
+        "IdentifiedCollections",
+        .product(name: "CollectionsBenchmark", package: "swift-collections-benchmark"),
+      ]
+    ),
+  ],
+  swiftLanguageVersions: [.v6]
+)
+
+#if !os(Windows)
+  // DocC needs to be ported to Windows
+  // https://github.com/thebrowsercompany/swift-build/issues/39
+  package.dependencies.append(
+    .package(url: "https://github.com/apple/swift-docc-plugin", from: "1.0.0")
+  )
+#endif

Sources/IdentifiedCollections/IdentifiedArray/IdentifiedArray+Initializers.swift

@@ -20,11 +20,10 @@ extension IdentifiedArray {
   ///   implements high-quality hashing.
   @inlinable
   @_disfavoredOverload
-  public init<S>(
-    uncheckedUniqueElements elements: S,
+  public init(
+    uncheckedUniqueElements elements: some Sequence<Element>,
     id: KeyPath<Element, ID>
-  )
-  where S: Sequence, S.Element == Element {
+  ) {
     self.init(
       id: id,
       _id: { $0[keyPath: id] },
@@ -46,11 +45,10 @@ extension IdentifiedArray {
   /// - Complexity: Expected O(*n*) on average, where *n* is the count of elements, if `ID`
   ///   implements high-quality hashing.
   @inlinable
-  public init<S>(
+  public init<S: Sequence<Element>>(
     uniqueElements elements: S,
     id: KeyPath<Element, ID>
-  )
-  where S: Sequence, S.Element == Element {
+  ) {
     if S.self == Self.self {
       self = elements as! Self
       return
@@ -82,11 +80,11 @@ extension IdentifiedArray {
   /// - Returns: A new array initialized with the unique elements of `elements`.
   /// - Complexity: Expected O(*n*) on average, where *n* is the count of elements, if `ID`
   ///   implements high-quality hashing.
-  public init<S: Sequence>(
-    _ elements: S,
+  public init(
+    _ elements: some Sequence<Element>,
     id: KeyPath<Element, ID>,
     uniquingIDsWith combine: (Element, Element) throws -> Element
-  ) rethrows where S.Element == Element {
+  ) rethrows {
     try self.init(
       id: id,
       _id: { $0[keyPath: id] },
@@ -146,7 +144,7 @@ extension IdentifiedArray where Element: Identifiable, ID == Element.ID {
   ///   implements high-quality hashing.
   @inlinable
   @_disfavoredOverload
-  public init<S>(uncheckedUniqueElements elements: S) where S: Sequence, S.Element == Element {
+  public init(uncheckedUniqueElements elements: some Sequence<Element>) {
     self.init(
       id: \.id,
       _id: { $0.id },
@@ -166,7 +164,7 @@ extension IdentifiedArray where Element: Identifiable, ID == Element.ID {
   /// - Complexity: Expected O(*n*) on average, where *n* is the count of elements, if `ID`
   ///   implements high-quality hashing.
   @inlinable
-  public init<S>(uniqueElements elements: S) where S: Sequence, S.Element == Element {
+  public init<S: Sequence<Element>>(uniqueElements elements: S) {
     if S.self == Self.self {
       self = elements as! Self
       return
@@ -198,10 +196,10 @@ extension IdentifiedArray where Element: Identifiable, ID == Element.ID {
   /// - Complexity: Expected O(*n*) on average, where *n* is the count of elements, if `ID`
   ///   implements high-quality hashing.
   @inlinable
-  public init<S: Sequence>(
-    _ elements: S,
+  public init(
+    _ elements: some Sequence<Element>,
     uniquingIDsWith combine: (Element, Element) throws -> Element
-  ) rethrows where S.Element == Element {
+  ) rethrows {
     try self.init(
       id: \.id,
       _id: { $0.id },
@@ -217,15 +215,15 @@ extension IdentifiedArray where Element: Identifiable, ID == Element.ID {
 
 extension IdentifiedArray {
   @available(*, deprecated, renamed: "init(uniqueElements:id:)")
-  public init<S>(_ elements: S, id: KeyPath<Element, ID>) where S: Sequence, S.Element == Element {
+  public init(_ elements: some Sequence<Element>, id: KeyPath<Element, ID>) {
     self.init(uniqueElements: elements, id: id)
   }
 }
 
 @available(iOS 13, macOS 10.15, tvOS 13, watchOS 6, *)
 extension IdentifiedArray where Element: Identifiable, ID == Element.ID {
   @available(*, deprecated, renamed: "init(uniqueElements:)")
-  public init<S>(_ elements: S) where S: Sequence, S.Element == Element {
+  public init(_ elements: some Sequence<Element>) {
     self.init(uniqueElements: elements)
   }
 }

Sources/IdentifiedCollections/IdentifiedArray/IdentifiedArray+Insertions.swift

@@ -23,8 +23,7 @@ extension IdentifiedArray {
   /// - Complexity: The operation is expected to perform amortized O(1) copy, hash, and compare
   ///   operations on the `Element` type, if it implements high-quality hashing.
   @inlinable
-  public mutating func append<S>(contentsOf newElements: S)
-  where Element == S.Element, S: Sequence {
+  public mutating func append(contentsOf newElements: some Sequence<Element>) {
     self.reserveCapacity(self.count + newElements.underestimatedCount)
     for element in newElements {
       self.append(element)

Sources/IdentifiedCollections/IdentifiedArray/IdentifiedArray+RangeReplaceableCollection.swift

@@ -14,8 +14,9 @@ where Element: Identifiable, ID == Element.ID {
   }
 
   @inlinable
-  public mutating func replaceSubrange<C: Collection>(_ subrange: Range<Int>, with newElements: C)
-  where C.Element == Element {
+  public mutating func replaceSubrange(
+    _ subrange: Range<Int>, with newElements: some Collection<Element>
+  ) {
     self._dictionary.removeSubrange(subrange)
     self._dictionary.reserveCapacity(self.count + newElements.count)
     for element in newElements.reversed() {

Sources/IdentifiedCollections/IdentifiedArray/IdentifiedArray+Sendable.swift

@@ -1,4 +1,2 @@
-#if swift(>=5.5)
-  extension IdentifiedArray: @unchecked Sendable
-  where ID: Sendable, Element: Sendable {}
-#endif
+extension IdentifiedArray: @unchecked Sendable
+where ID: Sendable, Element: Sendable {}

Sources/IdentifiedCollections/IdentifiedArray/IdentifiedArray.swift

@@ -261,7 +261,7 @@ import OrderedCollections
 /// should not be mutated in place, as it will drift from its associated dictionary key. Identified
 /// array is designed to avoid this invariant, with the exception of its *id-based* subscript.
 /// Mutating an element's id will result in a runtime error.
-public struct IdentifiedArray<ID, Element> where ID: Hashable {
+public struct IdentifiedArray<ID: Hashable, Element> {
   public let id: KeyPath<Element, ID>
 
   // NB: Captures identity access. Direct access to `Identifiable`'s `.id` property is faster than

Sources/swift-identified-collections-benchmark/main.swift

@@ -1,8 +1,13 @@
 import CollectionsBenchmark
 import IdentifiedCollections
 
-@available(iOS 13, macOS 10.15, tvOS 13, watchOS 6, *)
-extension Int: Identifiable { public var id: Self { self } }
+#if $RetroactiveAttribute
+  @available(iOS 13, macOS 10.15, tvOS 13, watchOS 6, *)
+  extension Int: @retroactive Identifiable { public var id: Self { self } }
+#else
+  @available(iOS 13, macOS 10.15, tvOS 13, watchOS 6, *)
+  extension Int: Identifiable { public var id: Self { self } }
+#endif
 
 if #available(iOS 13, macOS 10.15, tvOS 13, watchOS 6, *) {
   var benchmark = Benchmark(title: "Identified Collections Benchmark")

Tests/IdentifiedCollectionsTests/IdentifiedArrayTests.swift

@@ -2,7 +2,11 @@ import XCTest
 
 @testable import IdentifiedCollections
 
-extension Int: Identifiable { public var id: Self { self } }
+#if $RetroactiveAttribute
+  extension Int: @retroactive Identifiable { public var id: Self { self } }
+#else
+  extension Int: Identifiable { public var id: Self { self } }
+#endif
 
 private struct User: Equatable, Identifiable {
   let id: Int