Added: optional properties by key path

Sources/KeyValueCoding/Accessor.swift

@@ -28,7 +28,7 @@ protocol Accessor {}
 
 extension Accessor {
 
-    static func get(from pointer: UnsafeRawPointer) -> Any? {
+    static func get(from pointer: UnsafeRawPointer) -> Any {
         return pointer.assumingMemoryBound(to: Self.self).pointee
     }
 

Sources/KeyValueCoding/KeyValueCoding.swift

@@ -23,15 +23,6 @@
 //  THE SOFTWARE.
 //
 
-fileprivate extension Array {
-    mutating func popFirst() -> Element? {
-        guard count > 0 else {
-            return nil
-        }
-        return removeFirst()
-    }
-}
-
 fileprivate func withPointer<T>(_ instance: inout T, _ body: (UnsafeMutableRawPointer, Metadata) -> Any?) -> Any? {
     withUnsafePointer(to: &instance) {
         let metadata = swift_metadata(of: T.self)
@@ -70,22 +61,23 @@ fileprivate func withPointer<T>(_ instance: inout T, _ body: (UnsafeMutableRawPo
 }
 
 @discardableResult
-fileprivate func withProperty<T>(_ instance: inout T, path: [String], _ body: (Accessor.Type, UnsafeMutableRawPointer) -> Any?) -> Any? {
+fileprivate func withProperty<T>(_ instance: inout T, path: [String], _ body: (Metadata, UnsafeMutableRawPointer) -> Any?) -> Any? {
     withPointer(&instance) { pointer, metadata in
         var keys = path
-        guard let key = keys.popFirst(), let property = (metadata.properties.first { $0.name == key }) else {
+        guard let key = keys.popLast(), let property = (metadata.properties.first { $0.name == key }) else {
             return nil
         }
 
         let pointer = pointer.advanced(by: property.offset)
 
         if keys.isEmpty {
-            return body(property.metadata.accessor, pointer)
+            return body(property.metadata, pointer)
         }
-        else if var value = property.metadata.accessor.get(from: pointer) {
+        else if var value = property.metadata.get(from: pointer) {
             defer {
-                if property.metadata.kind == .struct {
-                    property.metadata.accessor.set(value: value, pointer: pointer)
+                let metadata = swift_metadata(of: type(of: value))
+                if metadata.kind == .struct {
+                    property.metadata.set(value: value, pointer: pointer)
                 }
             }
             return withProperty(&value, path: keys, body)
@@ -122,12 +114,9 @@ public func swift_metadata(of instance: Any) -> Metadata {
 ///     - key: The name of one of the instance's properties.
 /// - Returns: The value for the property identified by key.
 public func swift_value<T>(of instance: inout T, key: String) -> Any? {
-    let path = key.components(separatedBy: ".")
-    guard path.count > 0 else {
-        return nil
-    }
-    return withProperty(&instance, path: path) { accessor, pointer in
-        accessor.get(from: pointer)
+    let path: [String] = key.components(separatedBy: ".").reversed()
+    return withProperty(&instance, path: path) { metadata, pointer in
+        metadata.get(from: pointer)
     }
 }
 
@@ -138,12 +127,9 @@ public func swift_value<T>(of instance: inout T, key: String) -> Any? {
 ///     - value: The value for the property identified by key.
 ///     - key: The name of one of the instance's properties.
 public func swift_setValue<T>(_ value: Any?, to: inout T, key: String) {
-    let path = key.components(separatedBy: ".")
-    guard path.count > 0 else {
-        return
-    }
-    withProperty(&to, path: path) { accessor, pointer in
-        accessor.set(value: value as Any, pointer: pointer)
+    let path: [String] = key.components(separatedBy: ".").reversed()
+    withProperty(&to, path: path) { metadata, pointer in
+        metadata.set(value: value as Any, pointer: pointer)
     }
 }
 

Sources/KeyValueCoding/Metadata.swift

@@ -105,16 +105,14 @@ public struct Metadata {
 
     private let container: ProtocolTypeContainer
 
-    var accessor: Accessor.Type { container.accessor }
-
     /// Type.
     public let type: Any.Type
 
     /// Kind of the type.
     public let kind: Kind
 
     /// Size of the type.
-    public var size: Int { accessor.size }
+    public var size: Int { container.accessor.size }
 
     /// Accessible properties of the type.
     public let properties: [Property]
@@ -128,15 +126,11 @@ public struct Metadata {
         var fieldMetadata = _FieldReflectionMetadata()
         return (0..<count).compactMap {
             let propertyType = swift_reflectionMirror_recursiveChildMetadata(type, index: $0, fieldMetadata: &fieldMetadata)
-
             defer { fieldMetadata.freeFunc?(fieldMetadata.name) }
-            guard let propertyName = fieldMetadata.name.flatMap({ String(validatingUTF8: $0) }) else {
-                return nil
-            }
 
             let offset = swift_reflectionMirror_recursiveChildOffset(type, index: $0)
 
-            return Property(name: propertyName,
+            return Property(name: String(cString: fieldMetadata.name!),
                             isStrong: fieldMetadata.isStrong,
                             isVar: fieldMetadata.isVar,
                             offset: offset,
@@ -150,6 +144,22 @@ public struct Metadata {
         self.container = ProtocolTypeContainer(type: type)
         self.properties = Self.enumProperties(type: type, kind: self.kind)
     }
+
+    func get(from pointer: UnsafeRawPointer) -> Any? {
+        let value = container.accessor.get(from: pointer)
+
+        // Optional
+        if kind == .optional {
+            let mirror = Mirror(reflecting: value)
+            return mirror.children.first?.value
+        }
+
+        return value
+    }
+
+    func set(value: Any, pointer: UnsafeMutableRawPointer) {
+        container.accessor.set(value: value as Any, pointer: pointer)
+    }
 }
 
 class MetadataCache {