Update Swift tools version to 5.9 (#861)

* Update Swift tools version to 5.9

rdar://116871051

* Use if-let shorthand (SE-0345) available from Swift 5.7

* Modernize generics with opaque types (SE-0328 & SE-0341) available from Swift 5.7

This also leverages "primary associated types" (SE-0358) available from Swift 5.7

* Remove unused AnyCommunicationBridge type-erasure wrapper

* Remove back-port of pointer API (SE-0370) available in Swift 5.8

* Use package access level (SE-0386, available from Swift 5.9) instead of SPI for FileManagerProtocol

* Simplify extensions using bound generic types (SE-0361) available since Swift 5.7

* Use shorthand syntax for array, dictionary, and optional types (always available)

* Define primary associated type (SE-0346) for DirectiveArgument protocol

* Use opaque parameter types (SE-0341) in protocol definitions

* Use opaque return types (SE-0328) for some properties

* Use array and dictionary shorthand syntax in more places

* Use bound generic types (SE-0361) for extensions in more places

* Revert "Use package access level (SE-0386, available from Swift 5.9) instead of SPI for FileManagerProtocol"

f1ca44c

Author: d-ronnqvist

Dockerfile

@@ -1,12 +1,12 @@
 # This source file is part of the Swift.org open source project
 #
-# Copyright (c) 2021 Apple Inc. and the Swift project authors
+# Copyright (c) 2021-2024 Apple Inc. and the Swift project authors
 # Licensed under Apache License v2.0 with Runtime Library Exception
 #
 # See https://swift.org/LICENSE.txt for license information
 # See https://swift.org/CONTRIBUTORS.txt for Swift project authors
 
-FROM swift:5.5
+FROM swift:5.9-focal
 
 # Set up the current build user in the same way done in the Swift.org CI system: 
 # https://github.com/apple/swift-docker/blob/main/swift-ci/master/ubuntu/20.04/Dockerfile.

Package.swift

@@ -1,8 +1,8 @@
-// swift-tools-version:5.6
+// swift-tools-version:5.9
 /*
  This source file is part of the Swift.org open source project
 
- Copyright (c) 2021-2023 Apple Inc. and the Swift project authors
+ Copyright (c) 2021-2024 Apple Inc. and the Swift project authors
  Licensed under Apache License v2.0 with Runtime Library Exception
 
  See https://swift.org/LICENSE.txt for license information

Sources/SwiftDocC/Catalog Processing/GeneratedCurationWriter.swift

@@ -78,7 +78,7 @@ public struct GeneratedCurationWriter {
             // Calculate the longest link to nicely align all the comments
             let longestLink = links.map(\.link.count).max()! // `links` are non-empty so it's safe to force-unwrap `.max()` here
             for (link, comment) in links {
-                if let comment = comment {
+                if let comment {
                     text.append(link.padding(toLength: longestLink, withPad: " ", startingAt: 0))
                     text.append(comment)
                 } else {
@@ -127,7 +127,7 @@ public struct GeneratedCurationWriter {
             return [:]
         }
 
-        if let symbolLink = symbolLink {
+        if let symbolLink {
             switch context.linkResolver.resolve(UnresolvedTopicReference(topicURL: .init(symbolPath: symbolLink)), in: curationCrawlRoot, fromSymbolLink: true, context: context) {
             case .success(let foundSymbol):
                 curationCrawlRoot = foundSymbol
@@ -146,7 +146,7 @@ public struct GeneratedCurationWriter {
             }
 
             guard let absoluteLink = allAbsoluteLinks[usr], let curationText = defaultCurationText(for: reference) else { continue }
-            if let catalogURL = catalogURL, let existingURL = context.documentationExtensionURL(for: reference) {
+            if let catalogURL, let existingURL = context.documentationExtensionURL(for: reference) {
                 let updatedFileURL: URL
                 if catalogURL == outputURL {
                     updatedFileURL = existingURL

Sources/SwiftDocC/Checker/Checker.swift

@@ -181,7 +181,7 @@ public struct AnyChecker: Checker {
     private var box: AnyCheckerBox
 
     /// Creates an instance that type erases the given checker.
-    public init<C: Checker>(_ checker: C) {
+    public init(_ checker: some Checker) {
         self.box = CheckerBox(checker)
     }
 
@@ -270,7 +270,7 @@ public struct CompositeChecker: Checker {
     public var checkers: [AnyChecker]
 
     /// Creates a checker that performs the combined work of the given checkers.
-    public init<Checkers: Sequence>(_ checkers: Checkers) where Checkers.Element: Checker {
+    public init(_ checkers: some Sequence<Checker>) {
         self.checkers = checkers.map { $0.any() }
     }
 

Sources/SwiftDocC/Checker/Checkers/DuplicateTopicsSection.swift

@@ -35,7 +35,7 @@ public struct DuplicateTopicsSections: Checker {
         return duplicates.map { duplicateHeading -> Problem in
             let range = duplicateHeading.range!
             let notes: [DiagnosticNote]
-            if let sourceFile = sourceFile, let range = first.range {
+            if let sourceFile, let range = first.range {
                 notes = [DiagnosticNote(source: sourceFile, range: range, message: "First Topics Section starts here.")]
             } else {
                 notes = []

Sources/SwiftDocC/Checker/Checkers/NonInclusiveLanguageChecker.swift

@@ -110,7 +110,7 @@ public struct NonInclusiveLanguageChecker: Checker {
             explanation: term.message
         )
         var solutions: [Solution] = []
-        if let range = range {
+        if let range {
             let replacement = Replacement(range: range, replacement: term.replacement)
             let solution = Solution(summary: "Replace with \(term.replacement.singleQuoted)", replacements: [replacement])
             solutions.append(solution)

Sources/SwiftDocC/Checker/Checkers/NonOverviewHeadingChecker.swift

@@ -22,7 +22,7 @@ public struct NonOverviewHeadingChecker: Checker {
         return nonOverviewHeadings.compactMap { heading -> Problem? in
             guard let headingRange = heading.range else { return nil }
             let notes: [DiagnosticNote]
-            if let sourceFile = sourceFile, let range = overviewHeading?.range {
+            if let sourceFile, let range = overviewHeading?.range {
                 notes = [DiagnosticNote(source: sourceFile, range: range, message: "Overview section starts here")]
             } else {
                 notes = []

Sources/SwiftDocC/Converter/RenderNode+Coding.swift

@@ -213,7 +213,7 @@ public extension RenderNode {
         do {
             // If there is no topic reference cache, just encode the reference.
             // To skim a little off the duration we first do a quick check if the key is present at all.
-            guard let renderReferenceCache = renderReferenceCache else {
+            guard let renderReferenceCache else {
                 return try encoder.encode(self)
             }
 

Sources/SwiftDocC/Converter/TopicRenderReferenceEncoder.swift

@@ -94,7 +94,7 @@ enum TopicRenderReferenceEncoder {
 
                 // If a cache key was provided, update the cache with the reference and it's
                 // overrides.
-                if let cacheKey = cacheKey {
+                if let cacheKey {
                     referenceCache.sync { cache in
                         cache[cacheKey] = (
                             encodedReference,

Sources/SwiftDocC/Coverage/DocumentationCoverageOptions.swift

@@ -139,9 +139,7 @@ extension DocumentationCoverageOptions {
 }
 
 extension DocumentationCoverageOptions.KindFilterOptions {
-    public init<List>(bitFlags: List) where
-        List: Collection,
-        List.Element == BitFlagRepresentation {
+    public init(bitFlags: some Collection<BitFlagRepresentation>) {
         let mask = bitFlags.reduce(0) {
             $0 | $1.bitMask
         }