diff --git a/interop/src/cangjie/InteropTypes.cj b/interop/src/cangjie/InteropTypes.cj
index 993c8346eca71158524b8321f11f2583ed68ddc4..38197fc41b63a705bafe7b40ad4ccfae8234e981 100644
--- a/interop/src/cangjie/InteropTypes.cj
+++ b/interop/src/cangjie/InteropTypes.cj
@@ -20,8 +20,10 @@ public type KPointer = UInt64
 public type KFloat = Float32
 public type pointer = KPointer
 public type KInt = Int32
+public type KLong = Int64
 public type KStringPtr = String
 public type ArrayBuffer = ArrayList<UInt8>
+public const nullptr: UInt64 = 0
 @C
 public struct KInteropReturnBuffer {
   public var length: Int32
diff --git a/interop/src/cangjie/Finalizable.cj b/interop/src/cangjie/MaterializedBase.cj
similarity index 83%
rename from interop/src/cangjie/Finalizable.cj
rename to interop/src/cangjie/MaterializedBase.cj
index 5e26d0e8fc3a77cc0d4b3be04ecfdeb33a1de51b..362de947c7ac506d35fc45ec7348be4991bcf927 100644
--- a/interop/src/cangjie/Finalizable.cj
+++ b/interop/src/cangjie/MaterializedBase.cj
@@ -24,14 +24,11 @@ public open class Finalizable {
     }
 }
 
-public abstract class MaterializedBase {
-    public var peer: Option<Finalizable> = Option.None
+public interface MaterializedBase {
+    public func getPeer(): ?Finalizable
 
-    public func getPeer(): ?Finalizable {
-        return this.peer
-    }
-
-    public static func toPeerPtr(value: Object): KPointer {
+    public static func toPeerPtr(value: Any): KPointer
+    {
         let base: MaterializedBase = match (value as MaterializedBase) {
             case Some(x) => x
             case None => throw Exception("Value is not a MaterializedBase instance!")
diff --git a/interop/src/cangjie/SerializerBase.cj b/interop/src/cangjie/SerializerBase.cj
index 99df18ce96becca321931bc08668ce7c8c8e33ea..fdca1ae634db9a2391aaa688ab09504d45acb213 100644
--- a/interop/src/cangjie/SerializerBase.cj
+++ b/interop/src/cangjie/SerializerBase.cj
@@ -49,7 +49,7 @@ public enum RuntimeType {
     }
 }
 
-public class PromiseAndResourceId {
+public class PromiseAndResourceId<T> {
     public var promise: Any
     public var resourceId: ResourceId
     init (promise: Any, resourceId: ResourceId) {
@@ -137,21 +137,21 @@ public open class SerializerBase {
         this.writePointer(callSync)
         return resourceId
     }
-    public func holdAndWriteCallbackForPromiseVoid(): PromiseAndResourceId {
+    public func holdAndWriteCallbackForPromiseVoid(): PromiseAndResourceId<Unit> {
         return holdAndWriteCallbackForPromiseVoid(0, 0, 0, 0)
     }
-    public func holdAndWriteCallbackForPromiseVoid(hold: KPointer, release: KPointer, call: KPointer, callSync: KPointer): PromiseAndResourceId {
-        let resourceId: ResourceId
-        resourceId = this.holdAndWriteCallback({ => }, hold, release, call, callSync)
-        return PromiseAndResourceId({ => }, resourceId)
+    public func holdAndWriteCallbackForPromiseVoid(hold: KPointer, release: KPointer, call: KPointer, callSync: KPointer): PromiseAndResourceId<Unit> {
+        var resourceId: ResourceId = 0
+        let promise = { => }
+        return PromiseAndResourceId<Unit>(promise, resourceId)
     }
-    public func holdAndWriteCallbackForPromise<T>(): PromiseAndResourceId {
+    public func holdAndWriteCallbackForPromise<T>(): PromiseAndResourceId<T> {
         return holdAndWriteCallbackForPromise<T>(0, 0, 0)
     }
-    public func holdAndWriteCallbackForPromise<T>(hold: KPointer, release: KPointer, call: KPointer): PromiseAndResourceId {
-        let resourceId: ResourceId
-        resourceId = this.holdAndWriteCallback({ => }, hold, release, call, 0)
-        return PromiseAndResourceId({ => }, resourceId)
+    public func holdAndWriteCallbackForPromise<T>(hold: KPointer, release: KPointer, call: KPointer): PromiseAndResourceId<T> {
+        var resourceId: ResourceId = 0
+        let promise = { => }
+        return PromiseAndResourceId<T>(promise, resourceId)
     }
     public func writeFunction(value: Any): Unit {
         // TODO