add Field.Coded dynamic lookups for ObjectPublisher and ObjectSnapshot

CoreStoreTests/DynamicModelTests.swift

@@ -362,6 +362,7 @@ class DynamicModelTests: BaseTestDataTestCase {
                     XCTAssertEqual(person.name, personSnapshot1.$name)
                     XCTAssertEqual(person.title, personSnapshot1.$title)
                     XCTAssertEqual(person.displayName, personSnapshot1.$displayName)
+                    XCTAssertEqual(person.job, personSnapshot1.$job)
                     
                     person.title = "Sir"
                     XCTAssertEqual(person.displayName, "Sir John")
@@ -380,15 +381,19 @@ class DynamicModelTests: BaseTestDataTestCase {
                     XCTAssertEqual(person.name, personSnapshot2.$name)
                     XCTAssertEqual(person.title, personSnapshot2.$title)
                     XCTAssertEqual(person.displayName, personSnapshot2.$displayName)
+                    XCTAssertEqual(person.job, personSnapshot2.$job)
 
                     var personSnapshot3 = personSnapshot2
                     personSnapshot3.$name = "James"
                     XCTAssertEqual(personSnapshot1.$name, "John")
                     XCTAssertEqual(personSnapshot1.$displayName, "Mr. John")
+                    XCTAssertEqual(personSnapshot1.$job, .unemployed)
                     XCTAssertEqual(personSnapshot2.$name, "John")
                     XCTAssertEqual(personSnapshot2.$displayName, "Sir John")
+                    XCTAssertEqual(personSnapshot2.$job, .engineer)
                     XCTAssertEqual(personSnapshot3.$name, "James")
                     XCTAssertEqual(personSnapshot3.$displayName, "Sir John")
+                    XCTAssertEqual(personSnapshot3.$job, .engineer)
                     
 
                     
@@ -401,6 +406,14 @@ class DynamicModelTests: BaseTestDataTestCase {
                 },
                 success: { _ in
 
+                    let person = try! stack.fetchOne(From<Person>())
+                    XCTAssertNotNil(person)
+
+                    let personPublisher = person!.asPublisher(in: stack)
+                    XCTAssertEqual(personPublisher.$name, "John")
+                    XCTAssertEqual(personPublisher.$displayName, "Sir John")
+                    XCTAssertEqual(personPublisher.$job, .engineer)
+
                     updateDone.fulfill()
                 },
                 failure: { _ in

Sources/ObjectPublisher.swift

@@ -397,6 +397,21 @@ extension ObjectPublisher where O: CoreStoreObject {
         return FieldContainer<OBase>.Virtual<V>.read(field: object[keyPath: member], for: rawObject) as! V?
     }
 
+    /**
+     Returns the value for the property identified by a given key.
+     */
+    public subscript<OBase, V>(dynamicMember member: KeyPath<O, FieldContainer<OBase>.Coded<V>>) -> V? {
+
+        guard
+            let object = self.object,
+            let rawObject = object.rawObject
+            else {
+
+                return nil
+        }
+        return FieldContainer<OBase>.Coded<V>.read(field: object[keyPath: member], for: rawObject) as! V?
+    }
+
     /**
      Returns the value for the property identified by a given key.
      */

Sources/ObjectSnapshot.swift

@@ -209,6 +209,23 @@ extension ObjectSnapshot where O: CoreStoreObject {
         }
     }
 
+    /**
+     Returns the value for the property identified by a given key.
+     */
+    public subscript<OBase, V>(dynamicMember member: KeyPath<O, FieldContainer<OBase>.Coded<V>>) -> V {
+
+        get {
+
+            let key = String(keyPath: member)
+            return self.values[key] as! V
+        }
+        set {
+
+            let key = String(keyPath: member)
+            self.values[key] = newValue
+        }
+    }
+
     /**
      Returns the value for the property identified by a given key.
      */