Adding Support for Swift 6 (#292)

Adding Support for Swift 6 (#1)

Author: leogdion

Sources/XMLCoder/Auxiliaries/Box/DateBox.swift

@@ -8,7 +8,7 @@
 
 import Foundation
 
-struct DateBox: Equatable {
+struct DateBox: Equatable, Sendable {
     enum Format: Equatable {
         case secondsSince1970
         case millisecondsSince1970
@@ -44,7 +44,7 @@ struct DateBox: Equatable {
 
     init?(iso8601 string: String) {
         if #available(macOS 10.12, iOS 10.0, watchOS 3.0, tvOS 10.0, *) {
-            guard let unboxed = _iso8601Formatter.date(from: string) else {
+            guard let unboxed =  ISO8601DateFormatter.xmlCoderFormatter().date(from: string) else {
                 return nil
             }
             self.init(unboxed, format: .iso8601)
@@ -70,7 +70,7 @@ struct DateBox: Equatable {
             return milliseconds.description
         case .iso8601:
             if #available(macOS 10.12, iOS 10.0, watchOS 3.0, tvOS 10.0, *) {
-                return _iso8601Formatter.string(from: self.unboxed)
+                return ISO8601DateFormatter.xmlCoderFormatter().string(from: self.unboxed)
             } else {
                 fatalError("ISO8601DateFormatter is unavailable on this platform.")
             }

Sources/XMLCoder/Auxiliaries/ISO8601DateFormatter.swift

@@ -8,14 +8,10 @@
 
 import Foundation
 
-/// Shared ISO8601 Date Formatter
-/// NOTE: This value is implicitly lazy and _must_ be lazy. We're compiled
-/// against the latest SDK (w/ ISO8601DateFormatter), but linked against
-/// whichever Foundation the user has. ISO8601DateFormatter might not exist, so
-/// we better not hit this code path on an older OS.
-@available(macOS 10.12, iOS 10.0, watchOS 3.0, tvOS 10.0, *)
-var _iso8601Formatter: ISO8601DateFormatter = {
-    let formatter = ISO8601DateFormatter()
-    formatter.formatOptions = .withInternetDateTime
-    return formatter
-}()
+extension ISO8601DateFormatter {
+    static func xmlCoderFormatter() -> ISO8601DateFormatter {
+        let formatter = ISO8601DateFormatter()
+        formatter.formatOptions = .withInternetDateTime
+        return formatter
+    }
+}

Sources/XMLCoder/Encoder/DynamicNodeEncoding.swift

@@ -40,7 +40,7 @@
  </book>
  ```
  */
-public protocol DynamicNodeEncoding: Encodable {
+public protocol DynamicNodeEncoding: Encodable, Sendable {
     static func nodeEncoding(for key: CodingKey) -> XMLEncoder.NodeEncoding
 }
 

Sources/XMLCoder/Encoder/XMLEncoder.swift

@@ -13,7 +13,7 @@ open class XMLEncoder {
     // MARK: Options
 
     /// The formatting of the output XML data.
-    public struct OutputFormatting: OptionSet {
+    public struct OutputFormatting: OptionSet, Sendable {
         /// The format's default value.
         public let rawValue: UInt
 
@@ -39,7 +39,7 @@ open class XMLEncoder {
     }
 
     /// A node's encoding type. Specifies how a node will be encoded.
-    public enum NodeEncoding {
+    public enum NodeEncoding : Sendable {
         case attribute
         case element
         case both
@@ -233,8 +233,8 @@ open class XMLEncoder {
     @available(*, deprecated, renamed: "NodeEncodingStrategy")
     public typealias NodeEncodingStrategies = NodeEncodingStrategy
 
-    public typealias XMLNodeEncoderClosure = (CodingKey) -> NodeEncoding?
-    public typealias XMLEncodingClosure = (Encodable.Type, Encoder) -> XMLNodeEncoderClosure
+    public typealias XMLNodeEncoderClosure = @Sendable (CodingKey) -> NodeEncoding?
+    public typealias XMLEncodingClosure = @Sendable (Encodable.Type, Encoder) -> XMLNodeEncoderClosure
 
     /// Set of strategies to use for encoding of nodes.
     public enum NodeEncodingStrategy {
@@ -262,7 +262,13 @@ open class XMLEncoder {
             guard let dynamicType = codableType as? DynamicNodeEncoding.Type else {
                 return { _ in nil }
             }
-            return dynamicType.nodeEncoding(for:)
+            #if compiler(>=6.1)
+                return dynamicType.nodeEncoding(for:)
+            #else
+                return { (@Sendable key: CodingKey) in
+                    dynamicType.nodeEncoding(for: key)
+                }
+            #endif
         }
     }