Rewrite registrars in Java

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

@@ -0,0 +1,7 @@
+package juuxel.adorn.lib.registry;
+
+import java.util.function.Supplier;
+
+@FunctionalInterface
+public interface Registered<T> extends Supplier<T> {
+}

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

@@ -0,0 +1,10 @@
+package juuxel.adorn.lib.registry;
+
+import java.util.function.Supplier;
+
+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);
+}

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

@@ -0,0 +1,16 @@
+package juuxel.adorn.lib.registry;
+
+import juuxel.adorn.util.InlineServices;
+import juuxel.adorn.util.Services;
+import net.minecraft.registry.Registry;
+import net.minecraft.registry.RegistryKey;
+
+@InlineServices
+public interface RegistrarFactory {
+    <T> Registrar<T> create(RegistryKey<Registry<T>> registryKey);
+
+    @InlineServices.Getter
+    static RegistrarFactory get() {
+        return Services.load(RegistrarFactory.class);
+    }
+}

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

@@ -3,12 +3,12 @@
 import juuxel.adorn.AdornCommon;
 import juuxel.adorn.lib.registry.Registered;
 import juuxel.adorn.lib.registry.Registrar;
-import kotlin.jvm.functions.Function0;
 import net.minecraft.registry.Registry;
 
 import java.util.ArrayList;
 import java.util.Iterator;
 import java.util.List;
+import java.util.function.Supplier;
 
 public final class RegistrarImpl<T> implements Registrar<T> {
     private final Registry<T> registry;
@@ -19,8 +19,8 @@ public RegistrarImpl(Registry<T> registry) {
     }
 
     @Override
-    public <U extends T> Registered<U> register(String id, Function0<? extends U> provider) {
-        var registered = Registry.register(registry, AdornCommon.id(id), provider.invoke());
+    public <U extends T> Registered<U> register(String id, Supplier<? extends U> provider) {
+        var registered = Registry.register(registry, AdornCommon.id(id), provider.get());
         objects.add(registered);
         return () -> registered;
     }

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

@@ -3,7 +3,6 @@
 import com.google.common.collect.Iterators;
 import juuxel.adorn.AdornCommon;
 import juuxel.adorn.lib.registry.Registered;
-import kotlin.jvm.functions.Function0;
 import net.minecraft.registry.Registry;
 import net.minecraft.registry.RegistryKey;
 import net.neoforged.bus.api.IEventBus;
@@ -13,6 +12,7 @@
 import java.util.ArrayList;
 import java.util.Iterator;
 import java.util.List;
+import java.util.function.Supplier;
 
 public final class DeferredRegistrar<T> implements ForgeRegistrar<T> {
     private final DeferredRegister<T> register;
@@ -28,8 +28,8 @@ public void hook(IEventBus modBus) {
     }
 
     @Override
-    public <U extends T> Registered<U> register(String id, Function0<? extends U> provider) {
-        var registryObject = register.register(id, provider::invoke);
+    public <U extends T> Registered<U> register(String id, Supplier<? extends U> provider) {
+        var registryObject = register.register(id, provider);
         objects.add(registryObject);
         return registryObject::get;
     }