nullable, non-nullable reference

src/main/kotlin/nl/astraeus/persistence/reference/Reference.kt

@@ -6,10 +6,33 @@ import java.io.Serializable
 import kotlin.reflect.KProperty
 
 inline fun <reified T : Persistable> reference(
-) = Reference(T::class.java)
+  initialValue:T
+) = Reference(T::class.java, initialValue)
 
+inline fun <reified T : Persistable> nullableReference(
+) = NullableReference(T::class.java)
 
 class Reference<S : Persistable>(
+  val cls: Class<S>,
+  initialValue: S
+) : Serializable {
+  var id: Long = initialValue.id
+
+  operator fun getValue(thisRef: Persistable, property: KProperty<*>): S {
+    return currentTransaction()?.find(cls.kotlin, id) ?: throw IllegalStateException("Reference not found")
+  }
+
+  operator fun setValue(thisRef: Persistable, property: KProperty<*>, value: S) {
+    currentTransaction()?.store(value)
+    id = value.id
+  }
+
+  companion object {
+    private const val serialVersionUID: Long = 1L
+  }
+}
+
+class NullableReference<S : Persistable>(
   val cls: Class<S>
 ) : Serializable {
   var id: Long? = null
@@ -29,4 +52,4 @@ class Reference<S : Persistable>(
   companion object {
     private const val serialVersionUID: Long = 1L
   }
-}
+}