Initial Sendable Work (#128)

* Enable strict concurrency checking in 5.9

* Make some types we need Sendable Sendable

* Add new AsyncRouter that can be Sendable

* Remove AsyncRouter until I can work out how to handle that mess

Package@swift-5.9.swift

@@ -0,0 +1,35 @@
+// swift-tools-version:5.9
+import PackageDescription
+
+let package = Package(
+    name: "routing-kit",
+    platforms: [
+        .macOS(.v10_15),
+        .iOS(.v13),
+        .tvOS(.v13),
+        .watchOS(.v6),
+    ],
+    products: [
+        .library(name: "RoutingKit", targets: ["RoutingKit"]),
+    ],
+    dependencies: [
+        .package(url: "https://github.com/apple/swift-log.git", from: "1.5.3")
+    ],
+    targets: [
+        .target(
+            name: "RoutingKit",
+            dependencies: [
+                .product(name: "Logging", package: "swift-log"),
+            ],
+            swiftSettings: [
+                .enableExperimentalFeature("StrictConcurrency=complete"),
+            ]),
+        .testTarget(
+            name: "RoutingKitTests",
+            dependencies: ["RoutingKit"],
+            swiftSettings: [
+                .enableExperimentalFeature("StrictConcurrency=complete"),
+            ]
+        ),
+    ]
+)

Sources/RoutingKit/Parameters.swift

@@ -8,7 +8,7 @@ import Logging
 ///
 ///     let postID = parameters.get("post_id")
 ///
-public struct Parameters {
+public struct Parameters: Sendable {
     /// Internal storage.
     private var values: [String: String]
     private var catchall: Catchall

Sources/RoutingKit/PathComponent.swift

@@ -1,6 +1,6 @@
 /// A single path component of a `Route`. An array of these components describes
 /// a route's path, including which parts are constant and which parts are dynamic.
-public enum PathComponent: ExpressibleByStringInterpolation, CustomStringConvertible {
+public enum PathComponent: ExpressibleByStringInterpolation, CustomStringConvertible, Sendable {
     /// A normal, constant path component.
     case constant(String)
 

Sources/RoutingKit/TrieRouter.swift

@@ -8,7 +8,7 @@ import Logging
 /// See https://en.wikipedia.org/wiki/Trie for more information.
 public final class TrieRouter<Output>: Router, CustomStringConvertible {
     /// Available `TrieRouter` customization options.
-    public enum ConfigurationOption {
+    public enum ConfigurationOption: Sendable {
         /// If set, this will cause the router's route matching to be case-insensitive.
         /// - note: Case-insensitive routing may be less performant than case-sensitive routing.
         case caseInsensitive
@@ -18,7 +18,7 @@ public final class TrieRouter<Output>: Router, CustomStringConvertible {
     public var options: Set<ConfigurationOption>
 
     /// The root node.
-    private var root: Node
+    private let root: Node
 
     /// Configured logger.
     public let logger: Logger