Enable SE-0335 (Existential any) upcoming feature (#1181)

Author: d-ronnqvist

Package.swift

@@ -14,6 +14,8 @@ import class Foundation.ProcessInfo
 
 let swiftSettings: [SwiftSetting] = [
     .unsafeFlags(["-Xfrontend", "-warn-long-expression-type-checking=1000"], .when(configuration: .debug)),
+    
+    .enableUpcomingFeature("ExistentialAny"), // SE-0335: https://github.com/swiftlang/swift-evolution/blob/main/proposals/0335-existential-any.md
 ]
 
 let package = Package(

Sources/SwiftDocC/Benchmark/Benchmark.swift

@@ -53,7 +53,7 @@ public class Benchmark: Encodable {
     #endif
 
     /// The list of metrics included in this benchmark.
-    public var metrics: [BenchmarkMetric] = []
+    public var metrics: [any BenchmarkMetric] = []
 
     enum CodingKeys: String, CodingKey {
         case date, metrics, arguments, platform
@@ -71,8 +71,8 @@ public class Benchmark: Encodable {
             guard let result = log.result else {
                 return nil
             }
-            let id = (log as? DynamicallyIdentifiableMetric)?.identifier ?? type(of: log).identifier
-            let displayName = (log as? DynamicallyIdentifiableMetric)?.displayName ?? type(of: log).displayName
+            let id = (log as? (any DynamicallyIdentifiableMetric))?.identifier ?? type(of: log).identifier
+            let displayName = (log as? (any DynamicallyIdentifiableMetric))?.displayName ?? type(of: log).displayName
             return .init(id: id, displayName: displayName, value: result)
         }
 
@@ -84,13 +84,13 @@ public class Benchmark: Encodable {
         )
     }
 
-    public func encode(to encoder: Encoder) throws {
+    public func encode(to encoder: any Encoder) throws {
         try results()?.encode(to: encoder)
     }
 }
 
 private extension Benchmark {
-    func shouldLogMetricType(_ metricType: BenchmarkMetric.Type) -> Bool {
+    func shouldLogMetricType(_ metricType: any BenchmarkMetric.Type) -> Bool {
         return isEnabled && (metricsFilter == nil || metricType.identifier.hasPrefix(metricsFilter!))
     }
 }

Sources/SwiftDocC/Benchmark/BenchmarkResults.swift

@@ -97,7 +97,7 @@ public struct BenchmarkResults: Codable {
                 case duration, bytesInMemory, bytesOnDisk, checksum
             }
 
-            public init(from decoder: Decoder) throws {
+            public init(from decoder: any Decoder) throws {
                 let container = try decoder.container(keyedBy: CodingKeys.self)
 
                 switch try container.decode(ValueKind.self, forKey: .type) {
@@ -112,7 +112,7 @@ public struct BenchmarkResults: Codable {
                 }
             }
 
-            public func encode(to encoder: Encoder) throws {
+            public func encode(to encoder: any Encoder) throws {
                 var container = encoder.container(keyedBy: CodingKeys.self)
 
                 switch self {
@@ -149,7 +149,7 @@ extension BenchmarkResults {
         case platformName, timestamp, doccArguments, metrics
     }
 
-    public init(from decoder: Decoder) throws {
+    public init(from decoder: any Decoder) throws {
         let container = try decoder.container(keyedBy: CodingKeys.self)
 
         if container.contains(.platformName) {

Sources/SwiftDocC/Checker/Checker.swift

@@ -280,7 +280,7 @@ public struct CompositeChecker: Checker {
         }
     }
 
-    public mutating func visit(_ markup: Markup) -> () {
+    public mutating func visit(_ markup: any Markup) -> () {
         for i in checkers.indices {
             checkers[i].visit(markup)
         }

Sources/SwiftDocC/Checker/Checkers/AbstractContainsFormattedTextOnly.swift

@@ -43,7 +43,7 @@ public struct AbstractContainsFormattedTextOnly: Checker {
         }
     }
 
-    private mutating func foundInvalidContent(_ invalidContent: InvalidContent, markup: Markup) {
+    private mutating func foundInvalidContent(_ invalidContent: InvalidContent, markup: any Markup) {
         let explanation = """
             Summary should only contain (formatted) text. To resolve this issue, place links and images elsewhere in the document, or remove them.
             """

Sources/SwiftDocC/Checker/Checkers/NonInclusiveLanguageChecker.swift

@@ -129,7 +129,7 @@ public struct NonInclusiveLanguageChecker: Checker {
     ///   - markup: The markup element that contains the text.
     /// - Returns: An array of ranges at which the term was found.
     /// > Warning: Crashes if the term expression pattern is not valid.
-    func ranges(for term: Term, in text: String, of markup: Markup) -> [SourceRange] {
+    func ranges(for term: Term, in text: String, of markup: any Markup) -> [SourceRange] {
         var ranges = [SourceRange]()
 
         let regex = try! defaultRegularExpressions[term.expression]

Sources/SwiftDocC/Converter/Rewriter/RenderNodeTransformationComposition.swift

@@ -11,16 +11,16 @@
 /// A transformation that applies two transformations, one after the other.
 public struct RenderNodeTransformationComposition: RenderNodeTransforming {
     /// The first transformation to apply.
-    public var first: RenderNodeTransforming
+    public var first: any RenderNodeTransforming
     /// The second transformation to apply.
-    public var second: RenderNodeTransforming
+    public var second: any RenderNodeTransforming
 
     /// Initializes a transformation that applies two transformations, one after the other.
     ///
     /// - Parameters:
     ///   - first: The first transformation to apply.
     ///   - second: The second transformation to apply.
-    public init(first: RenderNodeTransforming, second: RenderNodeTransforming) {
+    public init(first: any RenderNodeTransforming, second: any RenderNodeTransforming) {
         self.first = first
         self.second = second
     }

Sources/SwiftDocC/Converter/Rewriter/RenderNodeTransformer.swift

@@ -37,7 +37,7 @@ open class RenderNodeTransformer {
     ///
     /// - Parameter transformation: The transformation to apply.
     /// - Returns: The transformed render node.
-    public func apply(transformation: RenderNodeTransforming) -> RenderNode {
+    public func apply(transformation: any RenderNodeTransforming) -> RenderNode {
         let context = RenderNodeTransformationContext(referencesCount: referencesCount)
 
         return transformation

Sources/SwiftDocC/Converter/Rewriter/RenderNodeTransforming.swift

@@ -27,7 +27,7 @@ extension RenderNodeTransforming {
     ///
     /// - Parameter otherTransformation: The other transformation to apply after the receiver.
     /// - Returns: A new transformation that applies the two transformations, one after another.
-    public func then(_ otherTransformation: RenderNodeTransforming) -> RenderNodeTransformationComposition {
+    public func then(_ otherTransformation: any RenderNodeTransforming) -> RenderNodeTransformationComposition {
         return RenderNodeTransformationComposition(first: self, second: otherTransformation)
     }
 }

Sources/SwiftDocC/Converter/TopicRenderReferenceEncoder.swift

@@ -23,7 +23,7 @@ enum TopicRenderReferenceEncoder {
     ///   instance to avoid encoding the same reference objects repeatedly.
     static func addRenderReferences(
         to renderNodeData: inout Data,
-        references: [String: RenderReference],
+        references: [String: any RenderReference],
         encodeAccumulatedVariantOverrides: Bool = false,
         encoder: JSONEncoder,
         renderReferenceCache referenceCache: RenderReferenceCache