Split Registered.key into a subinterface

Author: Juuxel

common/src/main/java/juuxel/adorn/lib/registry/Registered.java

@@ -4,6 +4,9 @@
 
 import java.util.function.Supplier;
 
+@FunctionalInterface
 public interface Registered<T> extends Supplier<T> {
-    RegistryKey<? super T> key();
+    interface WithKey<R, T extends R> extends Registered<T> {
+        RegistryKey<R> key();
+    }
 }

common/src/main/java/juuxel/adorn/lib/registry/RegisteredMap.java

@@ -10,7 +10,7 @@
 import java.util.function.Supplier;
 import java.util.stream.Stream;
 
-public final class RegisteredMap<K, V> implements Supplier<Map<K, V>> {
+public final class RegisteredMap<K, V> implements Registered<Map<K, V>> {
     private final Map<K, Registered<? extends V>> map;
     private final Supplier<Map<K, V>> builtMap;
 

common/src/main/java/juuxel/adorn/lib/registry/Registrar.java

@@ -10,7 +10,7 @@ public interface Registrar<T> extends Iterable<T> {
     /**
      * Registers an object with the id. The object is created using the provider.
      */
-    <U extends T> Registered<U> register(String id, Supplier<? extends U> provider);
+    <U extends T> Registered.WithKey<T, U> register(String id, Supplier<? extends U> provider);
 
     @SuppressWarnings("unchecked")
     default <K, U extends T> RegisteredMap<K, U> registerBy(Collection<? extends K> keys, Function<K, Registered<? extends U>> factory) {

fabric/src/main/java/juuxel/adorn/platform/fabric/RegistrarImpl.java

@@ -20,18 +20,18 @@ public RegistrarImpl(Registry<T> registry) {
     }
 
     @Override
-    public <U extends T> Registered<U> register(String id, Supplier<? extends U> provider) {
+    public <U extends T> Registered.WithKey<T, U> register(String id, Supplier<? extends U> provider) {
         var key = RegistryKey.of(registry.getKey(), AdornCommon.id(id));
         var registered = Registry.register(registry, key, provider.get());
         objects.add(registered);
-        return new Registered<>() {
+        return new Registered.WithKey<>() {
             @Override
             public U get() {
                 return registered;
             }
 
             @Override
-            public RegistryKey<? super U> key() {
+            public RegistryKey<T> key() {
                 return key;
             }
         };

forge/src/main/java/juuxel/adorn/platform/forge/registrar/DeferredRegistrar.java

@@ -29,12 +29,12 @@ public void hook(IEventBus modBus) {
     }
 
     @Override
-    public <U extends T> Registered<U> register(String id, Supplier<? extends U> provider) {
+    public <U extends T> Registered.WithKey<T, U> register(String id, Supplier<? extends U> provider) {
         var registryObject = register.register(id, provider);
         objects.add(registryObject);
-        return new Registered<>() {
+        return new Registered.WithKey<>() {
             @Override
-            public RegistryKey<? super U> key() {
+            public RegistryKey<T> key() {
                 return ((IHolderExtension<T>) registryObject).getKey();
             }