[patchwork, core, extensions] Hugely simplify Patchworks

gradle/libs.versions.toml

@@ -1,6 +1,5 @@
 [versions]
 assertj = "3.26.3"
-asm = "9.7"
 autoservice = "1.1.1"
 java-main = "8"
 java-test = "21"
@@ -16,8 +15,6 @@ lombok = { id = "io.freefair.lombok", version = "8.13.1" }
 
 [libraries]
 assertj = { group = "org.assertj", name = "assertj-core", version.ref = "assertj" }
-asm-commons = { group = "org.ow2.asm", name = "asm-commons", version.ref = "asm" }
-asm-core = { group = "org.ow2.asm", name = "asm", version.ref = "asm" }
 autoservice-annotations = { group = "com.google.auto.service", name = "auto-service-annotations", version.ref = "autoservice" }
 autoservice-processor = { group = "com.google.auto.service", name = "auto-service", version.ref = "autoservice" }
 jetbrains-annotations = { group = "org.jetbrains", name = "annotations", version.ref = "jetbrains-annotations" }

tweed5-core/src/main/java/de/siphalor/tweed5/core/api/container/ConfigContainer.java

@@ -1,13 +1,12 @@
 package de.siphalor.tweed5.core.api.container;
 
 import de.siphalor.tweed5.construct.api.TweedConstructFactory;
-import de.siphalor.tweed5.core.api.extension.EntryExtensionsData;
 import de.siphalor.tweed5.core.api.entry.ConfigEntry;
-import de.siphalor.tweed5.core.api.extension.RegisteredExtensionData;
 import de.siphalor.tweed5.core.api.extension.TweedExtension;
+import de.siphalor.tweed5.patchwork.api.Patchwork;
+import org.jspecify.annotations.Nullable;
 
 import java.util.Collection;
-import java.util.Map;
 import java.util.Optional;
 
 /**
@@ -16,7 +15,7 @@ import java.util.Optional;
  * @param <T> The class that the config tree represents
  * @see ConfigContainerSetupPhase
  */
-public interface ConfigContainer<T> {
+public interface ConfigContainer<T extends @Nullable Object> {
 	@SuppressWarnings("rawtypes")
 	TweedConstructFactory<ConfigContainer> FACTORY = TweedConstructFactory.builder(ConfigContainer.class).build();
 
@@ -36,10 +35,9 @@ public interface ConfigContainer<T> {
 
 	void attachTree(ConfigEntry<T> rootEntry);
 
-	EntryExtensionsData createExtensionsData();
+	Patchwork createExtensionsData();
 
 	void initialize();
 
 	ConfigEntry<T> rootEntry();
-	Map<Class<?>, ? extends RegisteredExtensionData<EntryExtensionsData, ?>> entryDataExtensions();
 }

tweed5-core/src/main/java/de/siphalor/tweed5/core/api/container/package-info.java

@@ -0,0 +1,4 @@
+@NullMarked
+package de.siphalor.tweed5.core.api.container;
+
+import org.jspecify.annotations.NullMarked;

tweed5-core/src/main/java/de/siphalor/tweed5/core/api/entry/BaseConfigEntry.java

@@ -1,14 +1,14 @@
 package de.siphalor.tweed5.core.api.entry;
 
 import de.siphalor.tweed5.core.api.container.ConfigContainer;
-import de.siphalor.tweed5.core.api.extension.EntryExtensionsData;
+import de.siphalor.tweed5.patchwork.api.Patchwork;
 import lombok.Getter;
 
 @Getter
 public abstract class BaseConfigEntry<T> implements ConfigEntry<T> {
 	private final ConfigContainer<?> container;
 	private final Class<T> valueClass;
-	private final EntryExtensionsData extensionsData;
+	private final Patchwork extensionsData;
 
 	public BaseConfigEntry(ConfigContainer<?> container, Class<T> valueClass) {
 		this.container = container;

tweed5-core/src/main/java/de/siphalor/tweed5/core/api/entry/CollectionConfigEntry.java

@@ -1,8 +1,15 @@
 package de.siphalor.tweed5.core.api.entry;
 
 import java.util.Collection;
+import java.util.function.Consumer;
 
 public interface CollectionConfigEntry<E, T extends Collection<E>> extends ConfigEntry<T> {
+	@Override
+	default CollectionConfigEntry<E, T> apply(Consumer<ConfigEntry<T>> function) {
+		ConfigEntry.super.apply(function);
+		return this;
+	}
+
 	ConfigEntry<E> elementEntry();
 
 	T instantiateCollection(int size);

tweed5-core/src/main/java/de/siphalor/tweed5/core/api/entry/CompoundConfigEntry.java

@@ -1,8 +1,15 @@
 package de.siphalor.tweed5.core.api.entry;
 
 import java.util.Map;
+import java.util.function.Consumer;
 
 public interface CompoundConfigEntry<T> extends ConfigEntry<T> {
+	@Override
+	default CompoundConfigEntry<T> apply(Consumer<ConfigEntry<T>> function) {
+		ConfigEntry.super.apply(function);
+		return this;
+	}
+
 	Map<String, ConfigEntry<?>> subEntries();
 
 	<V> void set(T compoundValue, String key, V value);

tweed5-core/src/main/java/de/siphalor/tweed5/core/api/entry/ConfigEntry.java

@@ -1,18 +1,32 @@
 package de.siphalor.tweed5.core.api.entry;
 
-import de.siphalor.tweed5.core.api.extension.EntryExtensionsData;
 import de.siphalor.tweed5.core.api.container.ConfigContainer;
+import de.siphalor.tweed5.patchwork.api.Patchwork;
+import org.jspecify.annotations.NonNull;
+import org.jspecify.annotations.Nullable;
 
-public interface ConfigEntry<T> {
+import java.util.function.Consumer;
+import java.util.function.Function;
+
+public interface ConfigEntry<T extends @Nullable Object> {
 
 	ConfigContainer<?> container();
 
 	Class<T> valueClass();
 
-	EntryExtensionsData extensionsData();
+	Patchwork extensionsData();
+
+	default ConfigEntry<T> apply(Consumer<ConfigEntry<T>> function) {
+		function.accept(this);
+		return this;
+	}
+
+	default <R> R call(Function<ConfigEntry<T>, R> function) {
+		return function.apply(this);
+	}
 
 	void visitInOrder(ConfigEntryVisitor visitor);
-	void visitInOrder(ConfigEntryValueVisitor visitor, T value);
+	void visitInOrder(ConfigEntryValueVisitor visitor, @Nullable T value);
 
-	T deepCopy(T value);
+	T deepCopy(@NonNull T value);
 }

tweed5-core/src/main/java/de/siphalor/tweed5/core/api/entry/SimpleConfigEntry.java

@@ -1,4 +1,11 @@
 package de.siphalor.tweed5.core.api.entry;
 
+import java.util.function.Consumer;
+
 public interface SimpleConfigEntry<T> extends ConfigEntry<T> {
+	@Override
+	default SimpleConfigEntry<T> apply(Consumer<ConfigEntry<T>> function) {
+		ConfigEntry.super.apply(function);
+		return this;
+	}
 }

tweed5-core/src/main/java/de/siphalor/tweed5/core/api/extension/EntryExtensionsData.java

@@ -1,6 +0,0 @@
-package de.siphalor.tweed5.core.api.extension;
-
-import de.siphalor.tweed5.patchwork.api.Patchwork;
-
-public interface EntryExtensionsData extends Patchwork<EntryExtensionsData> {
-}

tweed5-core/src/main/java/de/siphalor/tweed5/core/api/extension/RegisteredExtensionData.java

@@ -1,7 +0,0 @@
-package de.siphalor.tweed5.core.api.extension;
-
-import de.siphalor.tweed5.patchwork.api.Patchwork;
-
-public interface RegisteredExtensionData<U extends Patchwork<U>, E> {
-	void set(U patchwork, E extension);
-}

tweed5-core/src/main/java/de/siphalor/tweed5/core/api/extension/TweedExtensionSetupContext.java

@@ -1,6 +1,8 @@
 package de.siphalor.tweed5.core.api.extension;
 
+import de.siphalor.tweed5.patchwork.api.PatchworkPartAccess;
+
 public interface TweedExtensionSetupContext {
-	<E> RegisteredExtensionData<EntryExtensionsData, E> registerEntryExtensionData(Class<E> dataClass);
+	<E> PatchworkPartAccess<E> registerEntryExtensionData(Class<E> dataClass);
 	void registerExtension(Class<? extends TweedExtension> extensionClass);
 }

tweed5-core/src/main/java/de/siphalor/tweed5/core/impl/DefaultConfigContainer.java

@@ -3,21 +3,15 @@ package de.siphalor.tweed5.core.impl;
 import de.siphalor.tweed5.core.api.container.ConfigContainer;
 import de.siphalor.tweed5.core.api.container.ConfigContainerSetupPhase;
 import de.siphalor.tweed5.core.api.entry.ConfigEntry;
-import de.siphalor.tweed5.core.api.extension.EntryExtensionsData;
-import de.siphalor.tweed5.core.api.extension.RegisteredExtensionData;
 import de.siphalor.tweed5.core.api.extension.TweedExtension;
 import de.siphalor.tweed5.core.api.extension.TweedExtensionSetupContext;
 import de.siphalor.tweed5.patchwork.api.Patchwork;
-import de.siphalor.tweed5.patchwork.api.PatchworkClassCreator;
+import de.siphalor.tweed5.patchwork.api.PatchworkFactory;
-import de.siphalor.tweed5.patchwork.impl.PatchworkClass;
+import de.siphalor.tweed5.patchwork.api.PatchworkPartAccess;
-import de.siphalor.tweed5.patchwork.impl.PatchworkClassGenerator;
-import de.siphalor.tweed5.patchwork.impl.PatchworkClassPart;
 import de.siphalor.tweed5.utils.api.collection.InheritanceMap;
 import lombok.Getter;
-import lombok.Setter;
 import org.jspecify.annotations.Nullable;
 
-import java.lang.invoke.MethodHandle;
 import java.lang.reflect.Field;
 import java.lang.reflect.Modifier;
 import java.util.*;
@@ -28,9 +22,7 @@ public class DefaultConfigContainer<T> implements ConfigContainer<T> {
 	private final Set<Class<? extends TweedExtension>> requestedExtensions = new HashSet<>();
 	private final InheritanceMap<TweedExtension> extensions = new InheritanceMap<>(TweedExtension.class);
 	private @Nullable ConfigEntry<T> rootEntry;
-	private @Nullable PatchworkClass<EntryExtensionsData> entryExtensionsDataPatchworkClass;
+	private @Nullable PatchworkFactory entryExtensionsDataPatchworkFactory;
-	private final Map<Class<?>, RegisteredExtensionDataImpl<EntryExtensionsData, ?>> registeredEntryDataExtensions
-			= new HashMap<>();
 
 	@Override
 	public void registerExtension(Class<? extends TweedExtension> extensionClass) {
@@ -42,15 +34,12 @@ public class DefaultConfigContainer<T> implements ConfigContainer<T> {
 	public void finishExtensionSetup() {
 		requireSetupPhase(ConfigContainerSetupPhase.EXTENSIONS_SETUP);
 
+		PatchworkFactory.Builder entryExtensionDataPatchworkFactoryBuilder = PatchworkFactory.builder();
+
 		TweedExtensionSetupContext extensionSetupContext = new TweedExtensionSetupContext() {
 			@Override
-			public <E> RegisteredExtensionData<EntryExtensionsData, E> registerEntryExtensionData(Class<E> dataClass) {
+			public <E> PatchworkPartAccess<E> registerEntryExtensionData(Class<E> dataClass) {
-				if (registeredEntryDataExtensions.containsKey(dataClass)) {
+				return entryExtensionDataPatchworkFactoryBuilder.registerPart(dataClass);
-					throw new IllegalArgumentException("Extension " + dataClass.getName() + " is already registered");
-				}
-				RegisteredExtensionDataImpl<EntryExtensionsData, E> registered = new RegisteredExtensionDataImpl<>();
-				registeredEntryDataExtensions.put(dataClass, registered);
-				return registered;
 			}
 
 			@Override
@@ -81,20 +70,7 @@ public class DefaultConfigContainer<T> implements ConfigContainer<T> {
 			}
 		}
 
-		PatchworkClassCreator<EntryExtensionsData> entryExtensionsDataGenerator = PatchworkClassCreator.<EntryExtensionsData>builder()
+		entryExtensionsDataPatchworkFactory = entryExtensionDataPatchworkFactoryBuilder.build();
-				.patchworkInterface(EntryExtensionsData.class)
-				.classPackage("de.siphalor.tweed5.core.generated.entryextensiondata")
-				.classPrefix("EntryExtensionsData$")
-				.build();
-		try {
-			entryExtensionsDataPatchworkClass = entryExtensionsDataGenerator.createClass(registeredEntryDataExtensions.keySet());
-			for (PatchworkClassPart part : entryExtensionsDataPatchworkClass.parts()) {
-				RegisteredExtensionDataImpl<EntryExtensionsData, ?> registeredExtension = registeredEntryDataExtensions.get(part.partInterface());
-				registeredExtension.setter(part.fieldSetter());
-			}
-		} catch (PatchworkClassGenerator.GenerationException e) {
-			throw new IllegalStateException("Failed to create patchwork class for entry extensions' data", e);
-		}
 
 		setupPhase = ConfigContainerSetupPhase.TREE_SETUP;
 
@@ -230,25 +206,11 @@ public class DefaultConfigContainer<T> implements ConfigContainer<T> {
 	}
 
 	@Override
-	public EntryExtensionsData createExtensionsData() {
+	public Patchwork createExtensionsData() {
 		requireSetupPhase(ConfigContainerSetupPhase.TREE_SETUP);
 
-		try {
+		assert entryExtensionsDataPatchworkFactory != null;
-			assert entryExtensionsDataPatchworkClass != null;
+		return entryExtensionsDataPatchworkFactory.create();
-			return (EntryExtensionsData) entryExtensionsDataPatchworkClass.constructor().invoke();
-		} catch (Throwable e) {
-			throw new IllegalStateException("Failed to construct patchwork class for entry extensions' data", e);
-		}
-	}
-
-	@Override
-	public Map<Class<?>, ? extends RegisteredExtensionData<EntryExtensionsData, ?>> entryDataExtensions() {
-		requireSetupPhase(
-				ConfigContainerSetupPhase.TREE_SETUP,
-				ConfigContainerSetupPhase.TREE_ATTACHED,
-				ConfigContainerSetupPhase.INITIALIZED
-		);
-		return registeredEntryDataExtensions;
 	}
 
 	@Override
@@ -295,18 +257,4 @@ public class DefaultConfigContainer<T> implements ConfigContainer<T> {
 			);
 		}
 	}
-
-	@Setter
-	private static class RegisteredExtensionDataImpl<U extends Patchwork<U>, E> implements RegisteredExtensionData<U, E> {
-		private MethodHandle setter;
-
-		@Override
-		public void set(U patchwork, E extension) {
-			try {
-				setter.invokeWithArguments(patchwork, extension);
-			} catch (Throwable e) {
-				throw new IllegalStateException(e);
-			}
-		}
-	}
 }

tweed5-core/src/main/java/de/siphalor/tweed5/core/impl/entry/SimpleConfigEntryImpl.java

@@ -5,6 +5,7 @@ import de.siphalor.tweed5.core.api.entry.BaseConfigEntry;
 import de.siphalor.tweed5.core.api.entry.ConfigEntryValueVisitor;
 import de.siphalor.tweed5.core.api.entry.ConfigEntryVisitor;
 import de.siphalor.tweed5.core.api.entry.SimpleConfigEntry;
+import org.jspecify.annotations.NonNull;
 
 public class SimpleConfigEntryImpl<T> extends BaseConfigEntry<T> implements SimpleConfigEntry<T> {
 	public SimpleConfigEntryImpl(ConfigContainer<?> container, Class<T> valueClass) {
@@ -22,7 +23,7 @@ public class SimpleConfigEntryImpl<T> extends BaseConfigEntry<T> implements Simp
 	}
 
 	@Override
-	public T deepCopy(T value) {
+	public T deepCopy(@NonNull T value) {
 		return value;
 	}
 }

tweed5-core/src/test/java/de/siphalor/tweed5/core/impl/DefaultConfigContainerTest.java

@@ -2,8 +2,6 @@ package de.siphalor.tweed5.core.impl;
 
 import de.siphalor.tweed5.core.api.container.ConfigContainerSetupPhase;
 import de.siphalor.tweed5.core.api.entry.ConfigEntry;
-import de.siphalor.tweed5.core.api.extension.EntryExtensionsData;
-import de.siphalor.tweed5.core.api.extension.RegisteredExtensionData;
 import de.siphalor.tweed5.core.api.extension.TweedExtension;
 import de.siphalor.tweed5.core.api.extension.TweedExtensionSetupContext;
 import de.siphalor.tweed5.core.impl.entry.SimpleConfigEntryImpl;
@@ -131,28 +129,7 @@ class DefaultConfigContainerTest {
 		configContainer.registerExtension(ExtensionB.class);
 		configContainer.finishExtensionSetup();
 		var extensionData = configContainer.createExtensionsData();
-		assertThat(extensionData).isNotNull()
+		assertThat(extensionData).isNotNull();
-				.satisfies(
-						data -> assertThat(data.isPatchworkPartDefined(ExtensionBData.class)).isTrue(),
-						data -> assertThat(data.isPatchworkPartDefined(String.class)).isFalse()
-				);
-	}
-
-	@Test
-	void entryDataExtensions() {
-		var configContainer = new DefaultConfigContainer<>();
-		configContainer.registerExtension(ExtensionB.class);
-		configContainer.finishExtensionSetup();
-
-		assertThat(configContainer.entryDataExtensions()).containsOnlyKeys(ExtensionBData.class);
-		//noinspection unchecked
-		var registeredExtension = (RegisteredExtensionData<EntryExtensionsData, ExtensionBData>)
-				configContainer.entryDataExtensions().get(ExtensionBData.class);
-
-		var extensionsData = configContainer.createExtensionsData();
-		registeredExtension.set(extensionsData, new ExtensionBDataImpl("blub"));
-
-		assertThat(((ExtensionBData) extensionsData).test()).isEqualTo("blub");
 	}
 
 	@SuppressWarnings("unchecked")

tweed5-default-extensions/src/main/java/de/siphalor/tweed5/defaultextensions/comment/api/CommentExtension.java

@@ -5,8 +5,20 @@ import de.siphalor.tweed5.core.api.extension.TweedExtension;
 import de.siphalor.tweed5.defaultextensions.comment.impl.CommentExtensionImpl;
 import org.jspecify.annotations.Nullable;
 
+import java.util.function.Consumer;
+
 public interface CommentExtension extends TweedExtension {
 	Class<? extends CommentExtension> DEFAULT = CommentExtensionImpl.class;
 
+	static <C extends ConfigEntry<?>> Consumer<C> baseComment(String baseComment) {
+		return entry -> {
+			CommentExtension extension = entry.container().extension(CommentExtension.class)
+					.orElseThrow(() -> new IllegalStateException("No comment extension registered"));
+			extension.setBaseComment(entry, baseComment);
+		};
+	}
+
+	void setBaseComment(ConfigEntry<?> configEntry, String baseComment);
+
 	@Nullable String getFullComment(ConfigEntry<?> configEntry);
 }

tweed5-default-extensions/src/main/java/de/siphalor/tweed5/defaultextensions/comment/api/EntryComment.java

@@ -1,5 +0,0 @@
-package de.siphalor.tweed5.defaultextensions.comment.api;
-
-public interface EntryComment {
-	String comment();
-}

tweed5-default-extensions/src/main/java/de/siphalor/tweed5/defaultextensions/comment/impl/CommentExtensionImpl.java

@@ -2,32 +2,32 @@ package de.siphalor.tweed5.defaultextensions.comment.impl;
 
 import com.google.auto.service.AutoService;
 import de.siphalor.tweed5.core.api.container.ConfigContainer;
+import de.siphalor.tweed5.core.api.container.ConfigContainerSetupPhase;
 import de.siphalor.tweed5.core.api.entry.ConfigEntry;
-import de.siphalor.tweed5.core.api.extension.EntryExtensionsData;
-import de.siphalor.tweed5.core.api.extension.RegisteredExtensionData;
 import de.siphalor.tweed5.core.api.extension.TweedExtension;
 import de.siphalor.tweed5.core.api.extension.TweedExtensionSetupContext;
 import de.siphalor.tweed5.core.api.middleware.DefaultMiddlewareContainer;
 import de.siphalor.tweed5.core.api.middleware.Middleware;
 import de.siphalor.tweed5.data.extension.api.TweedEntryWriter;
 import de.siphalor.tweed5.data.extension.api.extension.ReadWriteRelatedExtension;
-import de.siphalor.tweed5.defaultextensions.comment.api.*;
+import de.siphalor.tweed5.defaultextensions.comment.api.CommentExtension;
+import de.siphalor.tweed5.defaultextensions.comment.api.CommentModifyingExtension;
+import de.siphalor.tweed5.defaultextensions.comment.api.CommentProducer;
+import de.siphalor.tweed5.patchwork.api.PatchworkPartAccess;
+import lombok.Data;
 import lombok.Getter;
-import lombok.Value;
-import org.jspecify.annotations.NonNull;
 import org.jspecify.annotations.Nullable;
 
 @AutoService(CommentExtension.class)
 public class CommentExtensionImpl implements ReadWriteRelatedExtension, CommentExtension {
 	private final ConfigContainer<?> configContainer;
 	@Getter
-	private final RegisteredExtensionData<EntryExtensionsData, InternalCommentEntryData> internalEntryDataExtension;
+	private final PatchworkPartAccess<CustomEntryData> customEntryDataAccess;
 	private final DefaultMiddlewareContainer<CommentProducer> middlewareContainer;
 
 	public CommentExtensionImpl(ConfigContainer<?> configContainer, TweedExtensionSetupContext context) {
 		this.configContainer = configContainer;
-		this.internalEntryDataExtension = context.registerEntryExtensionData(InternalCommentEntryData.class);
+		this.customEntryDataAccess = context.registerEntryExtensionData(CustomEntryData.class);
-		context.registerEntryExtensionData(EntryComment.class);
 		this.middlewareContainer = new DefaultMiddlewareContainer<>();
 	}
 
@@ -48,31 +48,49 @@ public class CommentExtensionImpl implements ReadWriteRelatedExtension, CommentE
 
 	@Override
 	public @Nullable Middleware<TweedEntryWriter<?, ?>> entryWriterMiddleware() {
-		return TweedEntryWriterCommentMiddleware.INSTANCE;
+		return new TweedEntryWriterCommentMiddleware(this);
+	}
+
+	@Override
+	public void setBaseComment(ConfigEntry<?> configEntry, String baseComment) {
+		if (configEntry.container() != configContainer) {
+			throw new IllegalArgumentException("config entry doesn't belong to config container of this extension");
+		} else if (configContainer.setupPhase().compareTo(ConfigContainerSetupPhase.INITIALIZED) >= 0) {
+			throw new IllegalStateException("config container must not be initialized");
+		}
+
+		getOrCreateCustomEntryData(configEntry).baseComment(baseComment);
 	}
 
 	@Override
 	public void initEntry(ConfigEntry<?> configEntry) {
-		EntryExtensionsData entryExtensionsData = configEntry.extensionsData();
+		CustomEntryData entryData = getOrCreateCustomEntryData(configEntry);
-		String baseComment;
+		entryData.commentProducer(middlewareContainer.process(entry -> entryData.baseComment()));
-		if (entryExtensionsData.isPatchworkPartSet(EntryComment.class)) {
+	}
-			baseComment = ((EntryComment) entryExtensionsData).comment();
-		} else {
-			baseComment = "";
-		}
 
-		CommentProducer middleware = middlewareContainer.process(entry -> baseComment);
+	private CustomEntryData getOrCreateCustomEntryData(ConfigEntry<?> entry) {
-		internalEntryDataExtension.set(entryExtensionsData, new InternalCommentEntryDataImpl(middleware));
+		CustomEntryData customEntryData = entry.extensionsData().get(customEntryDataAccess);
+		if (customEntryData == null) {
+			customEntryData = new CustomEntryData();
+			entry.extensionsData().set(customEntryDataAccess,  customEntryData);
+		}
+		return customEntryData;
 	}
 
 	@Override
-	public @Nullable String getFullComment(@NonNull ConfigEntry<?> configEntry) {
+	public @Nullable String getFullComment(ConfigEntry<?> configEntry) {
-		String comment = ((InternalCommentEntryData) configEntry.extensionsData()).commentProducer().createComment(configEntry);
+		CustomEntryData customEntryData = configEntry.extensionsData().get(customEntryDataAccess);
+		if (customEntryData == null) {
+			return null;
+		}
+		String comment = customEntryData.commentProducer().createComment(configEntry);
 		return comment.isEmpty() ? null : comment;
 	}
 
-	@Value
+
-	private static class InternalCommentEntryDataImpl implements InternalCommentEntryData {
+	@Data
-		CommentProducer commentProducer;
+	private static class CustomEntryData {
+		private String baseComment = "";
+		private CommentProducer commentProducer;
 	}
 }

tweed5-default-extensions/src/main/java/de/siphalor/tweed5/defaultextensions/comment/impl/InternalCommentEntryData.java

@@ -1,7 +0,0 @@
-package de.siphalor.tweed5.defaultextensions.comment.impl;
-
-import de.siphalor.tweed5.defaultextensions.comment.api.CommentProducer;
-
-public interface InternalCommentEntryData {
-	CommentProducer commentProducer();
-}

tweed5-default-extensions/src/main/java/de/siphalor/tweed5/defaultextensions/comment/impl/TweedEntryWriterCommentMiddleware.java

@@ -5,12 +5,14 @@ import de.siphalor.tweed5.core.api.entry.ConfigEntry;
 import de.siphalor.tweed5.core.api.middleware.Middleware;
 import de.siphalor.tweed5.data.extension.api.TweedEntryWriter;
 import de.siphalor.tweed5.dataapi.api.TweedDataVisitor;
+import de.siphalor.tweed5.defaultextensions.comment.api.CommentExtension;
 import lombok.RequiredArgsConstructor;
 import org.jspecify.annotations.NonNull;
 import org.jspecify.annotations.Nullable;
 
+@RequiredArgsConstructor
 class TweedEntryWriterCommentMiddleware implements Middleware<TweedEntryWriter<?, ?>> {
-	public static final TweedEntryWriterCommentMiddleware INSTANCE = new TweedEntryWriterCommentMiddleware();
+	private final CommentExtension commentExtension;
 
 	@Override
 	public String id() {
@@ -49,7 +51,7 @@ class TweedEntryWriterCommentMiddleware implements Middleware<TweedEntryWriter<?
 	}
 
 	@RequiredArgsConstructor
-	private static class CompoundDataVisitor implements TweedDataVisitor {
+	private class CompoundDataVisitor implements TweedDataVisitor {
 		private final TweedDataVisitor delegate;
 		private final CompoundConfigEntry<?> compoundConfigEntry;
 
@@ -134,11 +136,7 @@ class TweedEntryWriterCommentMiddleware implements Middleware<TweedEntryWriter<?
 		}
 	}
 
-	private static @Nullable String getEntryComment(ConfigEntry<?> entry) {
+	private @Nullable String getEntryComment(ConfigEntry<?> entry) {
-		if (!entry.extensionsData().isPatchworkPartSet(InternalCommentEntryData.class)) {
+		return commentExtension.getFullComment(entry);
-			return null;
-		}
-		String comment = ((InternalCommentEntryData) entry.extensionsData()).commentProducer().createComment(entry).trim();
-		return comment.isEmpty() ? null : comment;
 	}
 }

tweed5-default-extensions/src/main/java/de/siphalor/tweed5/defaultextensions/pather/api/PathTracking.java

@@ -5,7 +5,7 @@ import org.jspecify.annotations.Nullable;
 import java.util.ArrayDeque;
 import java.util.Deque;
 
-public class PathTracking implements PatherData {
+public class PathTracking {
 	private final StringBuilder pathBuilder = new StringBuilder(256);
 	private final Deque<Context> contextStack = new ArrayDeque<>(50);
 	private final Deque<String> pathParts = new ArrayDeque<>(50);
@@ -52,8 +52,7 @@ public class PathTracking implements PatherData {
 		return index;
 	}
 
-	@Override
+	public String currentPath() {
-	public String valuePath() {
 		return pathBuilder.toString();
 	}
 

tweed5-default-extensions/src/main/java/de/siphalor/tweed5/defaultextensions/pather/api/PathTrackingConfigEntryValueVisitor.java

@@ -3,6 +3,7 @@ package de.siphalor.tweed5.defaultextensions.pather.api;
 import de.siphalor.tweed5.core.api.entry.ConfigEntry;
 import de.siphalor.tweed5.core.api.entry.ConfigEntryValueVisitor;
 import lombok.RequiredArgsConstructor;
+import org.jspecify.annotations.Nullable;
 
 @RequiredArgsConstructor
 public class PathTrackingConfigEntryValueVisitor implements ConfigEntryValueVisitor {
@@ -10,7 +11,7 @@ public class PathTrackingConfigEntryValueVisitor implements ConfigEntryValueVisi
 	private final PathTracking pathTracking;
 
 	@Override
-	public <T> void visitEntry(ConfigEntry<T> entry, T value) {
+	public <T extends @Nullable Object> void visitEntry(ConfigEntry<T> entry, T value) {
 		delegate.visitEntry(entry, value);
 		entryVisited();
 	}

tweed5-default-extensions/src/main/java/de/siphalor/tweed5/defaultextensions/pather/api/PatherData.java

@@ -1,9 +0,0 @@
-package de.siphalor.tweed5.defaultextensions.pather.api;
-
-/**
- * Extension data for {@link de.siphalor.tweed5.data.extension.api.extension.ReadWriteContextExtensionsData}
- * that provides the path to the value currently being read/written.
- */
-public interface PatherData {
-	String valuePath();
-}

tweed5-default-extensions/src/main/java/de/siphalor/tweed5/defaultextensions/pather/api/PatherExtension.java

@@ -1,8 +1,13 @@
 package de.siphalor.tweed5.defaultextensions.pather.api;
 
 import de.siphalor.tweed5.core.api.extension.TweedExtension;
+import de.siphalor.tweed5.data.extension.api.TweedReadContext;
+import de.siphalor.tweed5.data.extension.api.TweedWriteContext;
 import de.siphalor.tweed5.defaultextensions.pather.impl.PatherExtensionImpl;
 
 public interface PatherExtension extends TweedExtension {
 	Class<? extends PatherExtension> DEFAULT = PatherExtensionImpl.class;
+
+	String getPath(TweedReadContext context);
+	String getPath(TweedWriteContext context);
 }

tweed5-default-extensions/src/main/java/de/siphalor/tweed5/defaultextensions/pather/impl/PatherExtensionImpl.java

@@ -2,29 +2,33 @@ package de.siphalor.tweed5.defaultextensions.pather.impl;
 
 import com.google.auto.service.AutoService;
 import de.siphalor.tweed5.core.api.entry.ConfigEntry;
-import de.siphalor.tweed5.core.api.extension.RegisteredExtensionData;
 import de.siphalor.tweed5.core.api.extension.TweedExtension;
 import de.siphalor.tweed5.core.api.middleware.Middleware;
-import de.siphalor.tweed5.data.extension.api.*;
+import de.siphalor.tweed5.data.extension.api.TweedEntryReader;
-import de.siphalor.tweed5.data.extension.api.extension.ReadWriteContextExtensionsData;
+import de.siphalor.tweed5.data.extension.api.TweedEntryWriter;
+import de.siphalor.tweed5.data.extension.api.TweedReadContext;
+import de.siphalor.tweed5.data.extension.api.TweedWriteContext;
 import de.siphalor.tweed5.data.extension.api.extension.ReadWriteExtensionSetupContext;
 import de.siphalor.tweed5.data.extension.api.extension.ReadWriteRelatedExtension;
 import de.siphalor.tweed5.dataapi.api.TweedDataReader;
 import de.siphalor.tweed5.dataapi.api.TweedDataVisitor;
-import de.siphalor.tweed5.defaultextensions.pather.api.*;
+import de.siphalor.tweed5.defaultextensions.pather.api.PathTracking;
+import de.siphalor.tweed5.defaultextensions.pather.api.PathTrackingDataReader;
+import de.siphalor.tweed5.defaultextensions.pather.api.PathTrackingDataVisitor;
+import de.siphalor.tweed5.defaultextensions.pather.api.PatherExtension;
+import de.siphalor.tweed5.patchwork.api.PatchworkPartAccess;
 import lombok.val;
 import org.jspecify.annotations.NonNull;
-import org.jspecify.annotations.NullUnmarked;
 import org.jspecify.annotations.Nullable;
 
 @AutoService(PatherExtension.class)
-@NullUnmarked
 public class PatherExtensionImpl implements PatherExtension, TweedExtension, ReadWriteRelatedExtension {
 	private static final String PATHER_ID = "pather";
 
-	private RegisteredExtensionData<ReadWriteContextExtensionsData, PatherData> rwContextPathTrackingData;
+	private final Middleware<TweedEntryReader<?, ?>> entryReaderMiddleware = createEntryReaderMiddleware();
-	private Middleware<TweedEntryReader<?, ?>> entryReaderMiddleware;
+	private final Middleware<TweedEntryWriter<?, ?>> entryWriterMiddleware = createEntryWriterMiddleware();
-	private Middleware<TweedEntryWriter<?, ?>> entryWriterMiddleware;
+
+	private @Nullable PatchworkPartAccess<PathTracking> rwContextPathTrackingAccess;
 
 	@Override
 	public String getId() {
@@ -33,13 +37,32 @@ public class PatherExtensionImpl implements PatherExtension, TweedExtension, Rea
 
 	@Override
 	public void setupReadWriteExtension(ReadWriteExtensionSetupContext context) {
-		rwContextPathTrackingData = context.registerReadWriteContextExtensionData(PatherData.class);
+		rwContextPathTrackingAccess = context.registerReadWriteContextExtensionData(PathTracking.class);
-
-		entryReaderMiddleware = createEntryReaderMiddleware();
-		entryWriterMiddleware = createEntryWriterMiddleware();
 	}
 
-	private @NonNull Middleware<TweedEntryReader<?, ?>> createEntryReaderMiddleware() {
+	@Override
+	public String getPath(TweedReadContext context) {
+		assert rwContextPathTrackingAccess != null;
+
+		PathTracking pathTracking = context.extensionsData().get(rwContextPathTrackingAccess);
+		if (pathTracking == null) {
+			throw new IllegalStateException("Path tracking is not active!");
+		}
+		return pathTracking.currentPath();
+	}
+
+	@Override
+	public String getPath(TweedWriteContext context) {
+		assert rwContextPathTrackingAccess != null;
+
+		PathTracking pathTracking = context.extensionsData().get(rwContextPathTrackingAccess);
+		if (pathTracking == null) {
+			throw new IllegalStateException("Path tracking is not active!");
+		}
+		return pathTracking.currentPath();
+	}
+
+	private Middleware<TweedEntryReader<?, ?>> createEntryReaderMiddleware() {
 		return new Middleware<TweedEntryReader<?, ?>>() {
 			@Override
 			public String id() {
@@ -48,16 +71,19 @@ public class PatherExtensionImpl implements PatherExtension, TweedExtension, Rea
 
 			@Override
 			public TweedEntryReader<?, ?> process(TweedEntryReader<?, ?> inner) {
+				assert rwContextPathTrackingAccess != null;
+
 				//noinspection unchecked
 				val castedInner = (TweedEntryReader<Object, @NonNull ConfigEntry<Object>>) inner;
 
 				return (TweedDataReader reader, ConfigEntry<Object> entry, TweedReadContext context) -> {
-					if (context.extensionsData().isPatchworkPartSet(PatherData.class)) {
+					PathTracking pathTracking = context.extensionsData().get(rwContextPathTrackingAccess);
+					if (pathTracking != null) {
 						return castedInner.read(reader, entry, context);
 					}
 
-					PathTracking pathTracking = new PathTracking();
+					pathTracking = new PathTracking();
-					rwContextPathTrackingData.set(context.extensionsData(), pathTracking);
+					context.extensionsData().set(rwContextPathTrackingAccess, pathTracking);
 					return castedInner.read(new PathTrackingDataReader(reader, pathTracking), entry, context);
 				};
 			}
@@ -73,17 +99,20 @@ public class PatherExtensionImpl implements PatherExtension, TweedExtension, Rea
 
 			@Override
 			public TweedEntryWriter<?, ?> process(TweedEntryWriter<?, ?> inner) {
+				assert rwContextPathTrackingAccess != null;
+
 				//noinspection unchecked
 				val castedInner = (TweedEntryWriter<Object, @NonNull ConfigEntry<Object>>) inner;
 
 				return (TweedDataVisitor writer, Object value, ConfigEntry<Object> entry, TweedWriteContext context) -> {
-					if (context.extensionsData().isPatchworkPartSet(PatherData.class)) {
+					PathTracking pathTracking = context.extensionsData().get(rwContextPathTrackingAccess);
+					if (pathTracking != null) {
 						castedInner.write(writer, value, entry, context);
 						return;
 					}
 
-					PathTracking pathTracking = new PathTracking();
+					pathTracking = new PathTracking();
-					rwContextPathTrackingData.set(context.extensionsData(), pathTracking);
+					context.extensionsData().set(rwContextPathTrackingAccess, pathTracking);
 					castedInner.write(new PathTrackingDataVisitor(writer, pathTracking), value, entry, context);
 				};
 			}

tweed5-default-extensions/src/main/java/de/siphalor/tweed5/defaultextensions/validation/api/EntrySpecificValidation.java

@@ -1,9 +0,0 @@
-package de.siphalor.tweed5.defaultextensions.validation.api;
-
-import de.siphalor.tweed5.core.api.middleware.Middleware;
-
-import java.util.Collection;
-
-public interface EntrySpecificValidation {
-	Collection<Middleware<ConfigEntryValidator>> validators();
-}

tweed5-default-extensions/src/main/java/de/siphalor/tweed5/defaultextensions/validation/api/ValidationExtension.java

@@ -2,12 +2,54 @@ package de.siphalor.tweed5.defaultextensions.validation.api;
 
 import de.siphalor.tweed5.core.api.entry.ConfigEntry;
 import de.siphalor.tweed5.core.api.extension.TweedExtension;
+import de.siphalor.tweed5.core.api.middleware.Middleware;
+import de.siphalor.tweed5.defaultextensions.validation.api.result.ValidationIssue;
 import de.siphalor.tweed5.defaultextensions.validation.api.result.ValidationIssues;
+import de.siphalor.tweed5.defaultextensions.validation.api.validators.SimpleValidatorMiddleware;
 import de.siphalor.tweed5.defaultextensions.validation.impl.ValidationExtensionImpl;
+import org.jetbrains.annotations.ApiStatus;
 import org.jspecify.annotations.Nullable;
 
+import java.util.*;
+import java.util.function.Consumer;
+import java.util.function.Function;
+
 public interface ValidationExtension extends TweedExtension {
 	Class<? extends ValidationExtension> DEFAULT = ValidationExtensionImpl.class;
 
+	static <C extends ConfigEntry<T>, T> Consumer<C> validators(ConfigEntryValidator... validators) {
+		return entry -> {
+			ValidationExtension extension = entry.container().extension(ValidationExtension.class)
+					.orElseThrow(() -> new IllegalStateException("No validation extension registered"));
+			extension.addValidators(entry, validators);
+		};
+	}
+
+	static <C extends ConfigEntry<T>, T> Function<C, ValidationIssues> validate(T value) {
+		return entry -> {
+			ValidationExtension extension = entry.container().extension(ValidationExtension.class)
+					.orElseThrow(() -> new IllegalStateException("No validation extension registered"));
+			return extension.validate(entry, value);
+		};
+	}
+
+	default <T> void addValidators(ConfigEntry<T> entry, ConfigEntryValidator... validators) {
+		String lastId = null;
+		for (ConfigEntryValidator validator : validators) {
+			String id = UUID.randomUUID().toString();
+			Set<String> mustComeAfter = lastId == null ? Collections.emptySet() : Collections.singleton(lastId);
+
+			addValidatorMiddleware(entry, new SimpleValidatorMiddleware(id, validator) {
+				@Override
+				public Set<String> mustComeAfter() {
+					return mustComeAfter;
+				}
+			});
+
+			lastId = id;
+		}
+	}
+	<T> void addValidatorMiddleware(ConfigEntry<T> entry, Middleware<ConfigEntryValidator> validator);
+
 	<T extends @Nullable Object> ValidationIssues validate(ConfigEntry<T> entry, T value);
 }

tweed5-default-extensions/src/main/java/de/siphalor/tweed5/defaultextensions/validation/api/result/ValidationResult.java

@@ -3,6 +3,7 @@ package de.siphalor.tweed5.defaultextensions.validation.api.result;
 import lombok.AccessLevel;
 import lombok.Getter;
 import lombok.RequiredArgsConstructor;
+import org.jspecify.annotations.Nullable;
 
 import java.util.ArrayList;
 import java.util.Collection;
@@ -11,16 +12,16 @@ import java.util.function.Function;
 
 @Getter
 @RequiredArgsConstructor(access = AccessLevel.PRIVATE)
-public class ValidationResult<T> {
+public class ValidationResult<T extends @Nullable Object> {
 	private final T value;
 	private final Collection<ValidationIssue> issues;
 	private final boolean hasError;
 
-	public static <T> ValidationResult<T> ok(T value) {
+	public static <T extends @Nullable Object> ValidationResult<T> ok(T value) {
 		return new ValidationResult<>(value, Collections.emptyList(), false);
 	}
 
-	public static <T> ValidationResult<T> withIssues(T value, Collection<ValidationIssue> issues) {
+	public static <T extends @Nullable Object> ValidationResult<T> withIssues(T value, Collection<ValidationIssue> issues) {
 		return new ValidationResult<>(value, issues, issuesContainError(issues));
 	}
 

tweed5-default-extensions/src/main/java/de/siphalor/tweed5/defaultextensions/validation/impl/InternalValidationEntryData.java

@@ -1,7 +0,0 @@
-package de.siphalor.tweed5.defaultextensions.validation.impl;
-
-import de.siphalor.tweed5.defaultextensions.validation.api.ConfigEntryValidator;
-
-public interface InternalValidationEntryData {
-	ConfigEntryValidator completeEntryValidator();
-}

tweed5-default-extensions/src/main/java/de/siphalor/tweed5/defaultextensions/validation/impl/ValidationExtensionImpl.java

@@ -4,8 +4,6 @@ import com.google.auto.service.AutoService;
 import de.siphalor.tweed5.core.api.container.ConfigContainer;
 import de.siphalor.tweed5.core.api.entry.ConfigEntry;
 import de.siphalor.tweed5.core.api.entry.ConfigEntryValueVisitor;
-import de.siphalor.tweed5.core.api.extension.EntryExtensionsData;
-import de.siphalor.tweed5.core.api.extension.RegisteredExtensionData;
 import de.siphalor.tweed5.core.api.extension.TweedExtension;
 import de.siphalor.tweed5.core.api.extension.TweedExtensionSetupContext;
 import de.siphalor.tweed5.core.api.middleware.DefaultMiddlewareContainer;
@@ -14,7 +12,6 @@ import de.siphalor.tweed5.core.api.middleware.MiddlewareContainer;
 import de.siphalor.tweed5.data.extension.api.TweedEntryReadException;
 import de.siphalor.tweed5.data.extension.api.TweedEntryReader;
 import de.siphalor.tweed5.data.extension.api.TweedReadContext;
-import de.siphalor.tweed5.data.extension.api.extension.ReadWriteContextExtensionsData;
 import de.siphalor.tweed5.data.extension.api.extension.ReadWriteExtensionSetupContext;
 import de.siphalor.tweed5.data.extension.api.extension.ReadWriteRelatedExtension;
 import de.siphalor.tweed5.dataapi.api.TweedDataReader;
@@ -22,20 +19,16 @@ import de.siphalor.tweed5.defaultextensions.comment.api.CommentModifyingExtensio
 import de.siphalor.tweed5.defaultextensions.comment.api.CommentProducer;
 import de.siphalor.tweed5.defaultextensions.pather.api.PathTracking;
 import de.siphalor.tweed5.defaultextensions.pather.api.PathTrackingConfigEntryValueVisitor;
-import de.siphalor.tweed5.defaultextensions.pather.api.PatherData;
 import de.siphalor.tweed5.defaultextensions.pather.api.PatherExtension;
 import de.siphalor.tweed5.defaultextensions.validation.api.ConfigEntryValidator;
-import de.siphalor.tweed5.defaultextensions.validation.api.EntrySpecificValidation;
 import de.siphalor.tweed5.defaultextensions.validation.api.ValidationExtension;
 import de.siphalor.tweed5.defaultextensions.validation.api.ValidationProvidingExtension;
 import de.siphalor.tweed5.defaultextensions.validation.api.result.ValidationIssue;
 import de.siphalor.tweed5.defaultextensions.validation.api.result.ValidationIssueLevel;
 import de.siphalor.tweed5.defaultextensions.validation.api.result.ValidationIssues;
 import de.siphalor.tweed5.defaultextensions.validation.api.result.ValidationResult;
-import lombok.Getter;
+import de.siphalor.tweed5.patchwork.api.PatchworkPartAccess;
-import lombok.RequiredArgsConstructor;
+import lombok.*;
-import lombok.Value;
-import org.jetbrains.annotations.NotNull;
 import org.jspecify.annotations.Nullable;
 
 import java.util.*;
@@ -48,7 +41,7 @@ public class ValidationExtensionImpl implements ReadWriteRelatedExtension, Valid
 	);
 	private static final ConfigEntryValidator PRIMITIVE_VALIDATOR = new ConfigEntryValidator() {
 		@Override
-		public <T> ValidationResult<T> validate(@NotNull ConfigEntry<T> configEntry, @Nullable T value) {
+		public <T> ValidationResult<T> validate(ConfigEntry<T> configEntry, @Nullable T value) {
 			if (value == null) {
 				//noinspection unchecked
 				return (ValidationResult<T>) PRIMITIVE_IS_NULL_RESULT;
@@ -57,33 +50,32 @@ public class ValidationExtensionImpl implements ReadWriteRelatedExtension, Valid
 		}
 
 		@Override
-		public <T> String description(@NotNull ConfigEntry<T> configEntry) {
+		public <T> String description(ConfigEntry<T> configEntry) {
 			return "Value must not be null.";
 		}
 	};
 	private static final ConfigEntryValidator NOOP_VALIDATOR = new ConfigEntryValidator() {
 		@Override
-		public <T> ValidationResult<T> validate(@NotNull ConfigEntry<T> configEntry, @Nullable T value) {
+		public <T> ValidationResult<@Nullable T> validate(ConfigEntry<T> configEntry, @Nullable T value) {
 			return ValidationResult.ok(value);
 		}
 
 		@Override
-		public <T> String description(@NotNull ConfigEntry<T> configEntry) {
+		public <T> String description(ConfigEntry<T> configEntry) {
 			return "";
 		}
 	};
 
 	private final ConfigContainer<?> configContainer;
-	private final RegisteredExtensionData<EntryExtensionsData, InternalValidationEntryData> validationEntryDataExtension;
+	private final PatchworkPartAccess<CustomEntryData> customEntryDataAccess;
 	private final MiddlewareContainer<ConfigEntryValidator> entryValidatorMiddlewareContainer
 			= new DefaultMiddlewareContainer<>();
-	private @Nullable RegisteredExtensionData<ReadWriteContextExtensionsData, ValidationIssues>
+	private @Nullable PatchworkPartAccess<ValidationIssues> readContextValidationIssuesAccess;
-			readContextValidationIssuesExtensionData;
+	private @Nullable PatherExtension patherExtension;
 
 	public ValidationExtensionImpl(ConfigContainer<?> configContainer, TweedExtensionSetupContext context) {
 		this.configContainer = configContainer;
-		this.validationEntryDataExtension = context.registerEntryExtensionData(InternalValidationEntryData.class);
+		this.customEntryDataAccess = context.registerEntryExtensionData(CustomEntryData.class);
-		context.registerEntryExtensionData(EntrySpecificValidation.class);
 		context.registerExtension(PatherExtension.class);
 	}
 
@@ -102,6 +94,9 @@ public class ValidationExtensionImpl implements ReadWriteRelatedExtension, Valid
 			}
 		}
 		entryValidatorMiddlewareContainer.seal();
+
+		patherExtension = configContainer.extension(PatherExtension.class)
+				.orElseThrow(() -> new IllegalStateException("Missing requested PatherExtension"));
 	}
 
 	@Override
@@ -116,16 +111,21 @@ public class ValidationExtensionImpl implements ReadWriteRelatedExtension, Valid
 			public CommentProducer process(CommentProducer inner) {
 				return entry -> {
 					String baseComment = inner.createComment(entry);
-					if (entry.extensionsData().isPatchworkPartSet(InternalValidationEntryData.class)) {
+					CustomEntryData entryData = entry.extensionsData().get(customEntryDataAccess);
-						String validationDescription = ((InternalValidationEntryData) entry.extensionsData())
+					if (entryData == null || entryData.completeValidator() == null) {
-								.completeEntryValidator()
+						return baseComment;
-								.description(entry)
+					}
-								.trim();
+					String validationDescription = entryData.completeValidator()
-						if (!validationDescription.isEmpty()) {
+							.description(entry)
-							baseComment += "\n\n" + validationDescription;
+							.trim();
-						}
+					if (validationDescription.isEmpty()) {
+						return baseComment;
+					}
+					if (baseComment.isEmpty()) {
+						return validationDescription;
+					} else {
+						return "\n\n" + validationDescription;
 					}
-					return baseComment;
 				};
 			}
 		};
@@ -133,7 +133,13 @@ public class ValidationExtensionImpl implements ReadWriteRelatedExtension, Valid
 
 	@Override
 	public void setupReadWriteExtension(ReadWriteExtensionSetupContext context) {
-		readContextValidationIssuesExtensionData = context.registerReadWriteContextExtensionData(ValidationIssues.class);
+		readContextValidationIssuesAccess = context.registerReadWriteContextExtensionData(ValidationIssues.class);
+	}
+
+	@Override
+	public <T> void addValidatorMiddleware(ConfigEntry<T> entry, Middleware<ConfigEntryValidator> validator) {
+		CustomEntryData entryData = getOrCreateCustomEntryData(entry);
+		entryData.addValidator(validator);
 	}
 
 	@Override
@@ -145,26 +151,26 @@ public class ValidationExtensionImpl implements ReadWriteRelatedExtension, Valid
 			baseValidator = NOOP_VALIDATOR;
 		}
 
-		ConfigEntryValidator entryValidator;
+		CustomEntryData entryData = getOrCreateCustomEntryData(configEntry);
-		Collection<Middleware<ConfigEntryValidator>> entrySpecificValidators = getEntrySpecificValidators(configEntry);
+
-		if (entrySpecificValidators.isEmpty()) {
+		if (entryData.validators().isEmpty()) {
-			entryValidator = entryValidatorMiddlewareContainer.process(baseValidator);
+			entryData.completeValidator(entryValidatorMiddlewareContainer.process(baseValidator));
 		} else {
 			DefaultMiddlewareContainer<ConfigEntryValidator> entrySpecificValidatorContainer = new DefaultMiddlewareContainer<>();
 			entrySpecificValidatorContainer.registerAll(entryValidatorMiddlewareContainer.middlewares());
-			entrySpecificValidatorContainer.registerAll(entrySpecificValidators);
+			entrySpecificValidatorContainer.registerAll(entryData.validators());
 			entrySpecificValidatorContainer.seal();
-			entryValidator = entrySpecificValidatorContainer.process(baseValidator);
+			entryData.completeValidator(entrySpecificValidatorContainer.process(baseValidator));
 		}
-
-		validationEntryDataExtension.set(configEntry.extensionsData(), new InternalValidationEntryDataImpl(entryValidator));
 	}
 
-	private Collection<Middleware<ConfigEntryValidator>> getEntrySpecificValidators(ConfigEntry<?> configEntry) {
+	private CustomEntryData getOrCreateCustomEntryData(ConfigEntry<?> entry) {
-		if (!configEntry.extensionsData().isPatchworkPartSet(EntrySpecificValidation.class)) {
+		CustomEntryData entryData = entry.extensionsData().get(customEntryDataAccess);
-			return Collections.emptyList();
+		if (entryData == null) {
+			entryData = new CustomEntryData();
+			entry.extensionsData().set(customEntryDataAccess, entryData);
 		}
-		return ((EntrySpecificValidation) configEntry.extensionsData()).validators();
+		return entryData;
 	}
 
 	@Override
@@ -173,7 +179,7 @@ public class ValidationExtensionImpl implements ReadWriteRelatedExtension, Valid
 	}
 
 	@Override
-	public <T> ValidationIssues validate(@NotNull ConfigEntry<T> entry, @Nullable T value) {
+	public <T> ValidationIssues validate(ConfigEntry<T> entry, @Nullable T value) {
 		PathTracking pathTracking = new PathTracking();
 		ValidatingConfigEntryVisitor validatingVisitor = new ValidatingConfigEntryVisitor(pathTracking);
 
@@ -182,9 +188,22 @@ public class ValidationExtensionImpl implements ReadWriteRelatedExtension, Valid
 		return validatingVisitor.validationIssues();
 	}
 
-	@Value
+	@Data
-	private static class InternalValidationEntryDataImpl implements InternalValidationEntryData {
+	private static class CustomEntryData {
-		ConfigEntryValidator completeEntryValidator;
+		@Setter(AccessLevel.NONE)
+		private @Nullable List<Middleware<ConfigEntryValidator>> validators;
+		private @Nullable ConfigEntryValidator completeValidator;
+
+		public List<Middleware<ConfigEntryValidator>> validators() {
+			return validators == null ? Collections.emptyList() : validators;
+		}
+
+		public void addValidator(Middleware<ConfigEntryValidator> validator) {
+			if (validators == null) {
+				validators = new ArrayList<>();
+			}
+			validators.add(validator);
+		}
 	}
 
 	private class EntryValidationReaderMiddleware implements Middleware<TweedEntryReader<?, ?>> {
@@ -200,23 +219,29 @@ public class ValidationExtensionImpl implements ReadWriteRelatedExtension, Valid
 
 		@Override
 		public TweedEntryReader<?, ?> process(TweedEntryReader<?, ?> inner) {
+			assert readContextValidationIssuesAccess != null && patherExtension != null;
+
 			//noinspection unchecked
 			TweedEntryReader<Object, ConfigEntry<Object>> castedInner = (TweedEntryReader<Object, ConfigEntry<Object>>) inner;
 			return (TweedDataReader reader, ConfigEntry<Object> entry, TweedReadContext context) -> {
-				ValidationIssues validationIssues;
+				ValidationIssues validationIssues = context.extensionsData().get(readContextValidationIssuesAccess);
-				if (!context.extensionsData().isPatchworkPartSet(ValidationIssues.class)) {
+				if (validationIssues == null) {
 					validationIssues = new ValidationIssuesImpl();
-					readContextValidationIssuesExtensionData.set(context.extensionsData(), validationIssues);
 				} else {
 					validationIssues = (ValidationIssues) context.extensionsData();
 				}
 
 				Object value = castedInner.read(reader, entry, context);
 
-				ValidationResult<Object> validationResult = ((InternalValidationEntryData) entry.extensionsData()).completeEntryValidator().validate(entry, value);
+				ConfigEntryValidator entryValidator = entry.extensionsData()
+						.get(customEntryDataAccess)
+						.completeValidator();
+				assert entryValidator != null;
 
-				if (!validationResult.issues().isEmpty() && context.extensionsData().isPatchworkPartSet(PatherData.class)) {
+				ValidationResult<Object> validationResult = entryValidator.validate(entry, value);
-					String path = ((PatherData) context.extensionsData()).valuePath();
+
+				if (!validationResult.issues().isEmpty()) {
+					String path = patherExtension.getPath(context);
 					validationIssues.issuesByPath().put(path, new ValidationIssues.EntryIssues(
 							entry,
 							validationResult.issues()
@@ -234,15 +259,19 @@ public class ValidationExtensionImpl implements ReadWriteRelatedExtension, Valid
 
 	@Getter
 	@RequiredArgsConstructor
-	private static class ValidatingConfigEntryVisitor implements ConfigEntryValueVisitor {
+	private class ValidatingConfigEntryVisitor implements ConfigEntryValueVisitor {
 		private final PathTracking pathTracking;
 		private final ValidationIssues validationIssues = new ValidationIssuesImpl();
 
 		@Override
 		public <T> void visitEntry(ConfigEntry<T> entry, T value) {
-			ValidationResult<T> result = ((InternalValidationEntryData) entry.extensionsData()).completeEntryValidator().validate(entry, value);
+			CustomEntryData entryData = entry.extensionsData().get(customEntryDataAccess);
+			assert entryData != null;
+			ConfigEntryValidator entryValidator = entryData.completeValidator();
+			assert entryValidator != null;
+			ValidationResult<T> result = entryValidator.validate(entry, value);
 			if (!result.issues().isEmpty()) {
-				validationIssues.issuesByPath().put(pathTracking.valuePath(), new ValidationIssues.EntryIssues(entry, result.issues()));
+				validationIssues.issuesByPath().put(pathTracking.currentPath(), new ValidationIssues.EntryIssues(entry, result.issues()));
 			}
 		}
 

tweed5-default-extensions/src/main/java/de/siphalor/tweed5/defaultextensions/validationfallback/api/ValidationFallbackExtension.java

@@ -1,8 +1,21 @@
 package de.siphalor.tweed5.defaultextensions.validationfallback.api;
 
+import de.siphalor.tweed5.core.api.entry.ConfigEntry;
 import de.siphalor.tweed5.core.api.extension.TweedExtension;
 import de.siphalor.tweed5.defaultextensions.validationfallback.impl.ValidationFallbackExtensionImpl;
 
+import java.util.function.Consumer;
+
 public interface ValidationFallbackExtension extends TweedExtension {
 	Class<? extends ValidationFallbackExtension> DEFAULT = ValidationFallbackExtensionImpl.class;
+
+	static <C extends ConfigEntry<T>, T> Consumer<C> validationFallbackValue(T value) {
+		return entry -> {
+			ValidationFallbackExtension extension = entry.container().extension(ValidationFallbackExtension.class)
+					.orElseThrow(() -> new IllegalStateException("ValidationFallbackExtension is not registered"));
+			extension.setFallbackValue(entry, value);
+		};
+	}
+
+	<T> void setFallbackValue(ConfigEntry<T> entry, T value);
 }

tweed5-default-extensions/src/main/java/de/siphalor/tweed5/defaultextensions/validationfallback/api/ValidationFallbackValue.java

@@ -1,7 +0,0 @@
-package de.siphalor.tweed5.defaultextensions.validationfallback.api;
-
-import org.jspecify.annotations.Nullable;
-
-public interface ValidationFallbackValue {
-	@Nullable Object validationFallbackValue();
-}

tweed5-default-extensions/src/main/java/de/siphalor/tweed5/defaultextensions/validationfallback/impl/ValidationFallbackExtensionImpl.java

@@ -10,7 +10,8 @@ import de.siphalor.tweed5.defaultextensions.validation.api.result.ValidationIssu
 import de.siphalor.tweed5.defaultextensions.validation.api.result.ValidationIssueLevel;
 import de.siphalor.tweed5.defaultextensions.validation.api.result.ValidationResult;
 import de.siphalor.tweed5.defaultextensions.validationfallback.api.ValidationFallbackExtension;
-import de.siphalor.tweed5.defaultextensions.validationfallback.api.ValidationFallbackValue;
+import de.siphalor.tweed5.patchwork.api.PatchworkPartAccess;
+import lombok.Data;
 import org.jspecify.annotations.Nullable;
 
 import java.util.ArrayList;
@@ -20,8 +21,11 @@ import java.util.stream.Collectors;
 
 @AutoService(ValidationFallbackExtension.class)
 public class ValidationFallbackExtensionImpl implements ValidationFallbackExtension, ValidationProvidingExtension {
+
+	private final PatchworkPartAccess<CustomEntryData> customEntryDataAccess;
+
 	public ValidationFallbackExtensionImpl(TweedExtensionSetupContext context) {
-		context.registerEntryExtensionData(ValidationFallbackValue.class);
+		customEntryDataAccess = context.registerEntryExtensionData(CustomEntryData.class);
 	}
 
 	@Override
@@ -29,12 +33,31 @@ public class ValidationFallbackExtensionImpl implements ValidationFallbackExtens
 		return "validation-fallback";
 	}
 
+	@Override
+	public <T> void setFallbackValue(ConfigEntry<T> entry, T value) {
+		getOrCreateCustomEntryData(entry).fallbackValue(value);
+	}
+
+	private CustomEntryData getOrCreateCustomEntryData(ConfigEntry<?> entry) {
+		CustomEntryData customEntryData = entry.extensionsData().get(customEntryDataAccess);
+		if (customEntryData == null) {
+			customEntryData = new CustomEntryData();
+			entry.extensionsData().set(customEntryDataAccess, customEntryData);
+		}
+		return customEntryData;
+	}
+
 	@Override
 	public Middleware<ConfigEntryValidator> validationMiddleware() {
 		return new ValidationFallbackMiddleware();
 	}
 
-	private static class ValidationFallbackMiddleware implements Middleware<ConfigEntryValidator> {
+	@Data
+	private static class CustomEntryData {
+		@Nullable Object fallbackValue;
+	}
+
+	private class ValidationFallbackMiddleware implements Middleware<ConfigEntryValidator> {
 		@Override
 		public String id() {
 			return "validation-fallback";
@@ -59,13 +82,14 @@ public class ValidationFallbackExtensionImpl implements ValidationFallbackExtens
 					if (!result.hasError()) {
 						return result;
 					}
-					if (!configEntry.extensionsData().isPatchworkPartSet(ValidationFallbackValue.class)) {
+					CustomEntryData entryData = configEntry.extensionsData().get(customEntryDataAccess);
+					if (entryData == null) {
 						return result;
 					}
 
-					Object fallbackValue = ((ValidationFallbackValue) configEntry.extensionsData()).validationFallbackValue();
+					Object fallbackValue = entryData.fallbackValue();
 					if (fallbackValue != null) {
-						if (fallbackValue.getClass() == configEntry.valueClass()) {
+						if (configEntry.valueClass().isInstance(fallbackValue)) {
 							//noinspection unchecked
 							fallbackValue = configEntry.deepCopy((T) fallbackValue);
 						} else {
@@ -90,12 +114,11 @@ public class ValidationFallbackExtensionImpl implements ValidationFallbackExtens
 
 				@Override
 				public <T> String description(ConfigEntry<T> configEntry) {
-					if (!configEntry.extensionsData().isPatchworkPartSet(ValidationFallbackValue.class)) {
+					CustomEntryData entryData = configEntry.extensionsData().get(customEntryDataAccess);
+					if (entryData == null) {
 						return inner.description(configEntry);
 					}
-					return inner.description(configEntry) +
+					return inner.description(configEntry) + "\n\nDefault/Fallback value: " + entryData.fallbackValue();
-							"\n\nDefault/Fallback value: " +
-							((ValidationFallbackValue) configEntry.extensionsData()).validationFallbackValue();
 				}
 			};
 		}

tweed5-default-extensions/src/test/java/de/siphalor/tweed5/defaultextensions/comment/impl/CommentExtensionImplTest.java

@@ -1,27 +1,20 @@
 package de.siphalor.tweed5.defaultextensions.comment.impl;
 
-import de.siphalor.tweed5.core.api.extension.EntryExtensionsData;
+import de.siphalor.tweed5.core.api.entry.CompoundConfigEntry;
-import de.siphalor.tweed5.core.api.extension.RegisteredExtensionData;
+import de.siphalor.tweed5.core.api.entry.SimpleConfigEntry;
 import de.siphalor.tweed5.core.api.extension.TweedExtension;
 import de.siphalor.tweed5.core.api.middleware.Middleware;
 import de.siphalor.tweed5.core.impl.DefaultConfigContainer;
 import de.siphalor.tweed5.core.impl.entry.SimpleConfigEntryImpl;
 import de.siphalor.tweed5.core.impl.entry.StaticMapCompoundConfigEntryImpl;
-import de.siphalor.tweed5.data.extension.api.EntryReaderWriterDefinition;
 import de.siphalor.tweed5.data.extension.api.ReadWriteExtension;
-import de.siphalor.tweed5.data.extension.api.TweedEntryReader;
-import de.siphalor.tweed5.data.extension.api.TweedEntryWriter;
-import de.siphalor.tweed5.data.extension.api.readwrite.TweedEntryReaderWriter;
-import de.siphalor.tweed5.data.extension.api.readwrite.TweedEntryReaderWriters;
 import de.siphalor.tweed5.data.hjson.HjsonCommentType;
 import de.siphalor.tweed5.data.hjson.HjsonWriter;
 import de.siphalor.tweed5.defaultextensions.comment.api.CommentExtension;
 import de.siphalor.tweed5.defaultextensions.comment.api.CommentModifyingExtension;
 import de.siphalor.tweed5.defaultextensions.comment.api.CommentProducer;
-import de.siphalor.tweed5.defaultextensions.comment.api.EntryComment;
 import lombok.NoArgsConstructor;
-import lombok.RequiredArgsConstructor;
+import org.jspecify.annotations.NonNull;
-import lombok.Value;
 import org.jspecify.annotations.NullUnmarked;
 import org.junit.jupiter.api.Test;
 
@@ -31,6 +24,9 @@ import java.util.LinkedHashMap;
 import java.util.List;
 import java.util.Map;
 
+import static de.siphalor.tweed5.data.extension.api.ReadWriteExtension.entryReaderWriter;
+import static de.siphalor.tweed5.data.extension.api.readwrite.TweedEntryReaderWriters.*;
+import static de.siphalor.tweed5.defaultextensions.comment.api.CommentExtension.baseComment;
 import static de.siphalor.tweed5.testutils.MapTestUtils.sequencedMap;
 import static java.util.Map.entry;
 import static org.junit.jupiter.api.Assertions.*;
@@ -38,44 +34,44 @@ import static org.junit.jupiter.api.Assertions.*;
 @NullUnmarked
 class CommentExtensionImplTest {
 
-	private DefaultConfigContainer<Map<String, Object>> configContainer;
+	private DefaultConfigContainer<@NonNull Map<String, Object>> configContainer;
-	private StaticMapCompoundConfigEntryImpl<Map<String, Object>> rootEntry;
+	private CompoundConfigEntry<Map<String, Object>> rootEntry;
-	private SimpleConfigEntryImpl<Integer> intEntry;
+	private SimpleConfigEntry<Integer> intEntry;
-	private SimpleConfigEntryImpl<String> stringEntry;
+	private SimpleConfigEntry<String> stringEntry;
-	private SimpleConfigEntryImpl<Long> noCommentEntry;
+	private SimpleConfigEntry<Long> noCommentEntry;
 
 	@SafeVarargs
 	final void setupContainer(Class<? extends TweedExtension>... extraExtensions) {
 		configContainer = new DefaultConfigContainer<>();
 
 		configContainer.registerExtension(CommentExtension.DEFAULT);
+		configContainer.registerExtension(ReadWriteExtension.DEFAULT);
 		configContainer.registerExtensions(extraExtensions);
 		configContainer.finishExtensionSetup();
 
-		intEntry = new SimpleConfigEntryImpl<>(configContainer, Integer.class);
+		intEntry = new SimpleConfigEntryImpl<>(configContainer, Integer.class)
-		stringEntry = new SimpleConfigEntryImpl<>(configContainer, String.class);
+				.apply(entryReaderWriter(intReaderWriter()))
-		noCommentEntry = new SimpleConfigEntryImpl<>(configContainer, Long.class);
+				.apply(baseComment("It is an integer"));
+		stringEntry = new SimpleConfigEntryImpl<>(configContainer, String.class)
+				.apply(entryReaderWriter(stringReaderWriter()))
+				.apply(baseComment("It is a string"));
+		noCommentEntry = new SimpleConfigEntryImpl<>(configContainer, Long.class)
+				.apply(entryReaderWriter(longReaderWriter()));
 
 		//noinspection unchecked
 		rootEntry = new StaticMapCompoundConfigEntryImpl<>(
 				configContainer,
-				((Class<Map<String, Object>>)(Class<?>) Map.class),
+				((Class<Map<String, Object>>) (Class<?>) Map.class),
 				LinkedHashMap::new,
 				sequencedMap(List.of(
 						entry("int", intEntry),
 						entry("string", stringEntry),
 						entry("noComment", noCommentEntry)
-				))
+				)))
-		);
+				.apply(entryReaderWriter(compoundReaderWriter()))
+				.apply(baseComment("This is the root value.\nIt is the topmost value in the tree."));
 
 		configContainer.attachTree(rootEntry);
-
-		//noinspection unchecked
-		RegisteredExtensionData<EntryExtensionsData, EntryComment> commentData = (RegisteredExtensionData<EntryExtensionsData, EntryComment>) configContainer.entryDataExtensions().get(EntryComment.class);
-
-		commentData.set(rootEntry.extensionsData(), new CommentImpl("This is the root value.\nIt is the topmost value in the tree."));
-		commentData.set(intEntry.extensionsData(), new CommentImpl("It is an integer"));
-		commentData.set(stringEntry.extensionsData(), new CommentImpl("It is a string"));
 	}
 
 	@Test
@@ -102,8 +98,7 @@ class CommentExtensionImplTest {
 
 	@Test
 	void simpleCommentsInHjson() {
-		setupContainer(ReadWriteExtension.DEFAULT);
+		setupContainer();
-		setupReadWriteTypes();
 		configContainer.initialize();
 
 		Map<String, Object> value = new HashMap<>();
@@ -134,21 +129,6 @@ class CommentExtensionImplTest {
 				""", output.toString());
 	}
 
-	private void setupReadWriteTypes() {
-		//noinspection unchecked
-		var readerWriterData = (RegisteredExtensionData<EntryExtensionsData, EntryReaderWriterDefinition>) configContainer.entryDataExtensions().get(EntryReaderWriterDefinition.class);
-
-		readerWriterData.set(rootEntry.extensionsData(), new TrivialEntryReaderWriterDefinition(TweedEntryReaderWriters.compoundReaderWriter()));
-		readerWriterData.set(intEntry.extensionsData(), new TrivialEntryReaderWriterDefinition(TweedEntryReaderWriters.intReaderWriter()));
-		readerWriterData.set(stringEntry.extensionsData(), new TrivialEntryReaderWriterDefinition(TweedEntryReaderWriters.stringReaderWriter()));
-		readerWriterData.set(noCommentEntry.extensionsData(), new TrivialEntryReaderWriterDefinition(TweedEntryReaderWriters.longReaderWriter()));
-	}
-
-	@Value
-	private static class CommentImpl implements EntryComment {
-		String comment;
-	}
-
 	@NoArgsConstructor
 	public static class TestCommentModifyingExtension implements TweedExtension, CommentModifyingExtension {
 		@Override
@@ -158,7 +138,7 @@ class CommentExtensionImplTest {
 
 		@Override
 		public Middleware<CommentProducer> commentMiddleware() {
-			return new Middleware<CommentProducer>() {
+			return new Middleware<>() {
 				@Override
 				public String id() {
 					return "test";
@@ -171,19 +151,4 @@ class CommentExtensionImplTest {
 			};
 		}
 	}
-
-	@RequiredArgsConstructor
-	private static class TrivialEntryReaderWriterDefinition implements EntryReaderWriterDefinition {
-		private final TweedEntryReaderWriter<?, ?> readerWriter;
-
-		@Override
-		public TweedEntryReader<?, ?> reader() {
-			return readerWriter;
-		}
-
-		@Override
-		public TweedEntryWriter<?, ?> writer() {
-			return readerWriter;
-		}
-	}
 }

tweed5-default-extensions/src/test/java/de/siphalor/tweed5/defaultextensions/validation/impl/ValidationExtensionImplTest.java

@@ -1,37 +1,39 @@
 package de.siphalor.tweed5.defaultextensions.validation.impl;
 
+import de.siphalor.tweed5.core.api.entry.CompoundConfigEntry;
 import de.siphalor.tweed5.core.api.entry.ConfigEntry;
-import de.siphalor.tweed5.core.api.extension.EntryExtensionsData;
+import de.siphalor.tweed5.core.api.entry.SimpleConfigEntry;
-import de.siphalor.tweed5.core.api.extension.RegisteredExtensionData;
 import de.siphalor.tweed5.core.impl.DefaultConfigContainer;
 import de.siphalor.tweed5.core.impl.entry.SimpleConfigEntryImpl;
 import de.siphalor.tweed5.core.impl.entry.StaticMapCompoundConfigEntryImpl;
 import de.siphalor.tweed5.defaultextensions.comment.api.CommentExtension;
-import de.siphalor.tweed5.defaultextensions.comment.api.EntryComment;
-import de.siphalor.tweed5.defaultextensions.validation.api.EntrySpecificValidation;
 import de.siphalor.tweed5.defaultextensions.validation.api.ValidationExtension;
 import de.siphalor.tweed5.defaultextensions.validation.api.result.ValidationIssue;
 import de.siphalor.tweed5.defaultextensions.validation.api.result.ValidationIssueLevel;
 import de.siphalor.tweed5.defaultextensions.validation.api.result.ValidationIssues;
 import de.siphalor.tweed5.defaultextensions.validation.api.validators.NumberRangeValidator;
-import de.siphalor.tweed5.defaultextensions.validation.api.validators.SimpleValidatorMiddleware;
 import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.Test;
 import org.junit.jupiter.params.ParameterizedTest;
 import org.junit.jupiter.params.provider.CsvSource;
 
-import java.util.*;
+import java.util.HashMap;
+import java.util.LinkedHashMap;
+import java.util.List;
+import java.util.Map;
 
+import static de.siphalor.tweed5.defaultextensions.comment.api.CommentExtension.baseComment;
+import static de.siphalor.tweed5.defaultextensions.validation.api.ValidationExtension.validators;
 import static de.siphalor.tweed5.testutils.MapTestUtils.sequencedMap;
 import static java.util.Map.entry;
 import static org.junit.jupiter.api.Assertions.*;
 
 class ValidationExtensionImplTest {
 	private DefaultConfigContainer<Map<String, Object>> configContainer;
-	private StaticMapCompoundConfigEntryImpl<Map<String, Object>> rootEntry;
+	private CompoundConfigEntry<Map<String, Object>> rootEntry;
-	private SimpleConfigEntryImpl<Byte> byteEntry;
+	private SimpleConfigEntry<Byte> byteEntry;
-	private SimpleConfigEntryImpl<Integer> intEntry;
+	private SimpleConfigEntry<Integer> intEntry;
-	private SimpleConfigEntryImpl<Double> doubleEntry;
+	private SimpleConfigEntry<Double> doubleEntry;
 
 	@BeforeEach
 	void setUp() {
@@ -41,9 +43,13 @@ class ValidationExtensionImplTest {
 		configContainer.registerExtension(ValidationExtension.DEFAULT);
 		configContainer.finishExtensionSetup();
 
-		byteEntry = new SimpleConfigEntryImpl<>(configContainer, Byte.class);
+		byteEntry = new SimpleConfigEntryImpl<>(configContainer, Byte.class)
-		intEntry = new SimpleConfigEntryImpl<>(configContainer, Integer.class);
+				.apply(validators(new NumberRangeValidator<>(Byte.class, (byte) 10, (byte) 100)));
-		doubleEntry = new SimpleConfigEntryImpl<>(configContainer, Double.class);
+		intEntry = new SimpleConfigEntryImpl<>(configContainer, Integer.class)
+				.apply(validators(new NumberRangeValidator<>(Integer.class, null, 123)))
+				.apply(baseComment("This is the main comment!"));
+		doubleEntry = new SimpleConfigEntryImpl<>(configContainer, Double.class)
+				.apply(validators(new NumberRangeValidator<>(Double.class, 0.5, null)));
 
 		//noinspection unchecked
 		rootEntry = new StaticMapCompoundConfigEntryImpl<>(
@@ -59,25 +65,6 @@ class ValidationExtensionImplTest {
 
 
 		configContainer.attachTree(rootEntry);
-
-		//noinspection unchecked
-		RegisteredExtensionData<EntryExtensionsData, EntryComment> commentData = (RegisteredExtensionData<EntryExtensionsData, EntryComment>) configContainer.entryDataExtensions().get(EntryComment.class);
-		commentData.set(intEntry.extensionsData(), () -> "This is the main comment!");
-		//noinspection unchecked
-		RegisteredExtensionData<EntryExtensionsData, EntrySpecificValidation> entrySpecificValidation = (RegisteredExtensionData<EntryExtensionsData, EntrySpecificValidation>) configContainer.entryDataExtensions().get(EntrySpecificValidation.class);
-		entrySpecificValidation.set(
-				byteEntry.extensionsData(),
-				() -> Collections.singleton(new SimpleValidatorMiddleware("range", new NumberRangeValidator<>(Byte.class, (byte) 10, (byte) 100)))
-		);
-		entrySpecificValidation.set(
-				intEntry.extensionsData(),
-				() -> Collections.singleton(new SimpleValidatorMiddleware("range", new NumberRangeValidator<>(Integer.class, null, 123)))
-		);
-		entrySpecificValidation.set(
-				doubleEntry.extensionsData(),
-				() -> Collections.singleton(new SimpleValidatorMiddleware("range", new NumberRangeValidator<>(Double.class, 0.5, null)))
-		);
-
 		configContainer.initialize();
 	}
 

tweed5-default-extensions/src/test/java/de/siphalor/tweed5/defaultextensions/validationfallback/impl/ValidationFallbackExtensionImplTest.java

@@ -1,30 +1,21 @@
 package de.siphalor.tweed5.defaultextensions.validationfallback.impl;
 
 import de.siphalor.tweed5.core.api.entry.ConfigEntry;
-import de.siphalor.tweed5.core.api.extension.EntryExtensionsData;
+import de.siphalor.tweed5.core.api.entry.SimpleConfigEntry;
-import de.siphalor.tweed5.core.api.extension.RegisteredExtensionData;
 import de.siphalor.tweed5.core.impl.DefaultConfigContainer;
 import de.siphalor.tweed5.core.impl.entry.SimpleConfigEntryImpl;
-import de.siphalor.tweed5.data.extension.api.EntryReaderWriterDefinition;
 import de.siphalor.tweed5.data.extension.api.ReadWriteExtension;
-import de.siphalor.tweed5.data.extension.api.TweedEntryReader;
-import de.siphalor.tweed5.data.extension.api.TweedEntryWriter;
-import de.siphalor.tweed5.data.extension.api.readwrite.TweedEntryReaderWriters;
 import de.siphalor.tweed5.data.hjson.HjsonCommentType;
 import de.siphalor.tweed5.data.hjson.HjsonLexer;
 import de.siphalor.tweed5.data.hjson.HjsonReader;
 import de.siphalor.tweed5.data.hjson.HjsonWriter;
 import de.siphalor.tweed5.defaultextensions.comment.api.CommentExtension;
 import de.siphalor.tweed5.defaultextensions.validation.api.ConfigEntryValidator;
-import de.siphalor.tweed5.defaultextensions.validation.api.EntrySpecificValidation;
 import de.siphalor.tweed5.defaultextensions.validation.api.ValidationExtension;
 import de.siphalor.tweed5.defaultextensions.validation.api.result.ValidationIssue;
 import de.siphalor.tweed5.defaultextensions.validation.api.result.ValidationIssueLevel;
 import de.siphalor.tweed5.defaultextensions.validation.api.result.ValidationResult;
-import de.siphalor.tweed5.defaultextensions.validation.api.validators.SimpleValidatorMiddleware;
 import de.siphalor.tweed5.defaultextensions.validationfallback.api.ValidationFallbackExtension;
-import de.siphalor.tweed5.defaultextensions.validationfallback.api.ValidationFallbackValue;
-import org.jetbrains.annotations.NotNull;
 import org.jspecify.annotations.Nullable;
 import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.Test;
@@ -33,18 +24,19 @@ import org.junit.jupiter.params.provider.ValueSource;
 
 import java.io.StringReader;
 import java.io.StringWriter;
-import java.util.Arrays;
 import java.util.Collections;
-import java.util.Set;
 
+import static de.siphalor.tweed5.data.extension.api.ReadWriteExtension.*;
+import static de.siphalor.tweed5.data.extension.api.readwrite.TweedEntryReaderWriters.*;
+import static de.siphalor.tweed5.defaultextensions.validation.api.ValidationExtension.validators;
+import static de.siphalor.tweed5.defaultextensions.validationfallback.api.ValidationFallbackExtension.validationFallbackValue;
 import static org.junit.jupiter.api.Assertions.assertDoesNotThrow;
 import static org.junit.jupiter.api.Assertions.assertEquals;
 
 class ValidationFallbackExtensionImplTest {
 	private DefaultConfigContainer<Integer> configContainer;
-	private SimpleConfigEntryImpl<Integer> intEntry;
+	private SimpleConfigEntry<Integer> intEntry;
 
-	@SuppressWarnings("unchecked")
 	@BeforeEach
 	void setUp() {
 		configContainer = new DefaultConfigContainer<>();
@@ -55,92 +47,82 @@ class ValidationFallbackExtensionImplTest {
 
 		configContainer.finishExtensionSetup();
 
-		intEntry = new SimpleConfigEntryImpl<>(configContainer, Integer.class);
+		intEntry = new SimpleConfigEntryImpl<>(configContainer, Integer.class)
+				.apply(entryReaderWriter(nullableReader(intReaderWriter()), nullableWriter(intReaderWriter())))
+				.apply(validators(
+						new ConfigEntryValidator() {
+							@Override
+							public <T extends @Nullable Object> ValidationResult<T> validate(ConfigEntry<T> configEntry, @Nullable T value) {
+								if (value == null) {
+									return ValidationResult.withIssues(
+											null, Collections.singleton(
+													new ValidationIssue(
+															"Value must not be null",
+															ValidationIssueLevel.ERROR
+													)
+											)
+									);
+								}
+								return ValidationResult.ok(value);
+							}
+
+							@Override
+							public <T> String description(ConfigEntry<T> configEntry) {
+								return "Must not be null.";
+							}
+						},
+						new ConfigEntryValidator() {
+
+							@Override
+							public <T> ValidationResult<T> validate(ConfigEntry<T> configEntry, @Nullable T value) {
+								assert value != null;
+								int intValue = (int) value;
+								if (intValue < 1) {
+									return ValidationResult.withIssues(
+											value,
+											Collections.singleton(new ValidationIssue(
+													"Must be greater or equal to 1",
+													ValidationIssueLevel.ERROR
+											))
+									);
+								}
+								if (intValue > 6) {
+									return ValidationResult.withIssues(
+											value,
+											Collections.singleton(new ValidationIssue(
+													"Must be smaller or equal to 6",
+													ValidationIssueLevel.ERROR
+											))
+									);
+								}
+								return ValidationResult.ok(value);
+							}
+
+							@Override
+							public <T> String description(ConfigEntry<T> configEntry) {
+								return "Must be between 1 and 6";
+							}
+						}
+				))
+				.apply(validationFallbackValue(3));
+
 		configContainer.attachTree(intEntry);
-
-		RegisteredExtensionData<EntryExtensionsData, EntrySpecificValidation> entrySpecificValidation = (RegisteredExtensionData<EntryExtensionsData, EntrySpecificValidation>) configContainer.entryDataExtensions().get(EntrySpecificValidation.class);
-		entrySpecificValidation.set(intEntry.extensionsData(), () -> Arrays.asList(
-				new SimpleValidatorMiddleware("non-null", new ConfigEntryValidator() {
-					@Override
-					public <T> ValidationResult<T> validate(ConfigEntry<T> configEntry, @Nullable T value) {
-						if (value == null) {
-							return ValidationResult.withIssues(null, Collections.singleton(
-									new ValidationIssue("Value must not be null", ValidationIssueLevel.ERROR)
-							));
-						}
-						return ValidationResult.ok(value);
-					}
-
-					@Override
-					public @NotNull <T> String description(ConfigEntry<T> configEntry) {
-						return "Must not be null.";
-					}
-				}),
-				new SimpleValidatorMiddleware("range", new ConfigEntryValidator() {
-					@Override
-					public <T> ValidationResult<T> validate(ConfigEntry<T> configEntry, @Nullable T value) {
-						Integer intValue = (Integer) value;
-						if (intValue < 1) {
-							return ValidationResult.withIssues(value, Collections.singleton(new ValidationIssue("Must be greater or equal to 1", ValidationIssueLevel.ERROR)));
-						}
-						if (intValue > 6) {
-							return ValidationResult.withIssues(value, Collections.singleton(new ValidationIssue("Must be smaller or equal to 6", ValidationIssueLevel.ERROR)));
-						}
-						return ValidationResult.ok(value);
-					}
-
-					@Override
-					public @NotNull <T> String description(ConfigEntry<T> configEntry) {
-						return "Must be between 1 and 6";
-					}
-				}) {
-					@Override
-					public Set<String> mustComeAfter() {
-						return Collections.singleton("non-null");
-					}
-				}
-		));
-
-		RegisteredExtensionData<EntryExtensionsData, ValidationFallbackValue> validationFallbackValue = (RegisteredExtensionData<EntryExtensionsData, ValidationFallbackValue>) configContainer.entryDataExtensions().get(ValidationFallbackValue.class);
-		validationFallbackValue.set(intEntry.extensionsData(), () -> 3);
-
-		RegisteredExtensionData<EntryExtensionsData, EntryReaderWriterDefinition> readerWriterData = (RegisteredExtensionData<EntryExtensionsData, EntryReaderWriterDefinition>) configContainer.entryDataExtensions().get(EntryReaderWriterDefinition.class);
-		readerWriterData.set(intEntry.extensionsData(), new EntryReaderWriterDefinition() {
-			@Override
-			public TweedEntryReader<?, ?> reader() {
-				return TweedEntryReaderWriters.nullableReader(TweedEntryReaderWriters.intReaderWriter());
-			}
-
-			@Override
-			public TweedEntryWriter<?, ?> writer() {
-				return TweedEntryReaderWriters.nullableWriter(TweedEntryReaderWriters.intReaderWriter());
-			}
-		});
-
 		configContainer.initialize();
 	}
 
 	@ParameterizedTest
 	@ValueSource(strings = {"0", "7", "123", "null"})
 	void fallbackTriggers(String input) {
-		ReadWriteExtension readWriteExtension = configContainer.extension(ReadWriteExtension.class).orElseThrow();
+		Integer result = intEntry.call(read(new HjsonReader(new HjsonLexer(new StringReader(input)))));
-		Integer result = assertDoesNotThrow(() -> readWriteExtension.read(
-				new HjsonReader(new HjsonLexer(new StringReader(input))),
-				intEntry,
-				readWriteExtension.createReadWriteContextExtensionsData()
-		));
 		assertEquals(3, result);
 	}
 
 	@Test
 	void description() {
-		ReadWriteExtension readWriteExtension = configContainer.extension(ReadWriteExtension.class).orElseThrow();
 		StringWriter stringWriter = new StringWriter();
-		assertDoesNotThrow(() -> readWriteExtension.write(
+		intEntry.apply(write(
 				new HjsonWriter(stringWriter, new HjsonWriter.Options().multilineCommentType(HjsonCommentType.SLASHES)),
-				5,
+				5
-				intEntry,
-				readWriteExtension.createReadWriteContextExtensionsData()
 		));
 
 		assertEquals(

tweed5-patchwork/build.gradle.kts

@@ -1,8 +1,3 @@
 plugins {
     id("de.siphalor.tweed5.base-module")
 }
-
-dependencies {
-    implementation(libs.asm.core)
-    implementation(libs.asm.commons)
-}

tweed5-patchwork/src/main/java/de/siphalor/tweed5/patchwork/api/InvalidPatchworkAccessException.java

@@ -0,0 +1,7 @@
+package de.siphalor.tweed5.patchwork.api;
+
+public class InvalidPatchworkAccessException extends RuntimeException {
+	public InvalidPatchworkAccessException(String message) {
+		super(message);
+	}
+}

tweed5-patchwork/src/main/java/de/siphalor/tweed5/patchwork/api/Patchwork.java

@@ -1,8 +1,16 @@
 package de.siphalor.tweed5.patchwork.api;
 
-public interface Patchwork<S extends Patchwork<S>> {
+import org.jetbrains.annotations.CheckReturnValue;
-	boolean isPatchworkPartDefined(Class<?> patchworkInterface);
+import org.jetbrains.annotations.Contract;
-	boolean isPatchworkPartSet(Class<?> patchworkInterface);
+import org.jspecify.annotations.Nullable;
 
-	S copy();
+public interface Patchwork {
+	@Contract(pure = true)
+	<T extends @Nullable Object> @Nullable T get(PatchworkPartAccess<T> access) throws InvalidPatchworkAccessException;
+	@Contract(mutates = "this")
+	<T extends @Nullable Object> void set(PatchworkPartAccess<T> access, T value) throws InvalidPatchworkAccessException;
+
+	@CheckReturnValue
+	@Contract(pure = true)
+	Patchwork copy();
 }

tweed5-patchwork/src/main/java/de/siphalor/tweed5/patchwork/api/PatchworkClassCreator.java

@@ -1,90 +0,0 @@
-package de.siphalor.tweed5.patchwork.api;
-
-import de.siphalor.tweed5.patchwork.impl.ByteArrayClassLoader;
-import de.siphalor.tweed5.patchwork.impl.PatchworkClass;
-import de.siphalor.tweed5.patchwork.impl.PatchworkClassGenerator;
-import de.siphalor.tweed5.patchwork.impl.PatchworkClassPart;
-import lombok.AccessLevel;
-import lombok.NoArgsConstructor;
-import lombok.Setter;
-import lombok.Value;
-
-import java.lang.invoke.MethodHandle;
-import java.lang.invoke.MethodHandles;
-import java.lang.invoke.MethodType;
-import java.util.Collection;
-import java.util.Collections;
-import java.util.List;
-import java.util.stream.Collectors;
-
-@Value
-public class PatchworkClassCreator<P extends Patchwork<P>> {
-	Class<P> patchworkInterface;
-	PatchworkClassGenerator.Config generatorConfig;
-
-	public static <P extends Patchwork<P>> Builder<P> builder() {
-		return new Builder<>();
-	}
-
-	public PatchworkClass<P> createClass(Collection<Class<?>> partInterfaces) throws
-			PatchworkClassGenerator.GenerationException {
-		List<PatchworkClassPart> parts = partInterfaces.stream()
-				.map(PatchworkClassPart::new)
-				.collect(Collectors.toList());
-
-		PatchworkClassGenerator generator = new PatchworkClassGenerator(generatorConfig, parts);
-		try {
-			generator.verify();
-		} catch (PatchworkClassGenerator.VerificationException e) {
-			throw new IllegalArgumentException(e);
-		}
-		generator.generate();
-		byte[] classBytes = generator.emit();
-		//noinspection unchecked
-		Class<P> patchworkClass = (Class<P>) ByteArrayClassLoader.loadClass(null, classBytes);
-
-		MethodHandles.Lookup lookup = MethodHandles.publicLookup();
-		for (PatchworkClassPart part : parts) {
-			try {
-				MethodHandle setterHandle = lookup.findSetter(patchworkClass, part.fieldName(), part.partInterface());
-				part.fieldSetter(setterHandle);
-			} catch (NoSuchFieldException | IllegalAccessException e) {
-				throw new IllegalStateException(
-						"Failed to access setter for patchwork part " + part.partInterface().getName(),
-						e
-				);
-			}
-		}
-		try {
-			MethodHandle constructorHandle = lookup.findConstructor(patchworkClass, MethodType.methodType(Void.TYPE));
-
-			return PatchworkClass.<P>builder()
-					.classPackage(generatorConfig.classPackage())
-					.className(generator.className())
-					.theClass(patchworkClass)
-					.constructor(constructorHandle)
-					.parts(parts)
-					.build();
-
-		} catch (NoSuchMethodException | IllegalAccessException e) {
-			throw new IllegalStateException("Failed to access constructor of patchwork class", e);
-		}
-	}
-
-	@Setter
-	@NoArgsConstructor(access = AccessLevel.PRIVATE)
-	public static class Builder<P extends Patchwork<P>> {
-		private Class<P> patchworkInterface;
-		private String classPackage;
-		private String classPrefix = "";
-
-		public PatchworkClassCreator<P> build() {
-			return new PatchworkClassCreator<>(
-					patchworkInterface,
-					new PatchworkClassGenerator.Config(classPackage)
-							.classPrefix(classPrefix)
-							.markerInterfaces(Collections.singletonList(patchworkInterface))
-			);
-		}
-	}
-}

tweed5-patchwork/src/main/java/de/siphalor/tweed5/patchwork/api/PatchworkFactory.java

@@ -0,0 +1,16 @@
+package de.siphalor.tweed5.patchwork.api;
+
+import de.siphalor.tweed5.patchwork.impl.PatchworkFactoryImpl;
+
+public interface PatchworkFactory {
+	static Builder builder() {
+		return new PatchworkFactoryImpl.Builder();
+	}
+
+	Patchwork create();
+
+	interface Builder {
+		<T> PatchworkPartAccess<T> registerPart(Class<T> partClass);
+		PatchworkFactory build();
+	}
+}

tweed5-patchwork/src/main/java/de/siphalor/tweed5/patchwork/api/PatchworkPartAccess.java

@@ -0,0 +1,6 @@
+package de.siphalor.tweed5.patchwork.api;
+
+import org.jspecify.annotations.Nullable;
+
+public interface PatchworkPartAccess<T extends @Nullable Object> {
+}

tweed5-patchwork/src/main/java/de/siphalor/tweed5/patchwork/api/PatchworkPartIsNullException.java

@@ -1,7 +0,0 @@
-package de.siphalor.tweed5.patchwork.api;
-
-public class PatchworkPartIsNullException extends RuntimeException {
-	public PatchworkPartIsNullException(String message) {
-		super(message);
-	}
-}

tweed5-patchwork/src/main/java/de/siphalor/tweed5/patchwork/impl/ByteArrayClassLoader.java

@@ -1,21 +0,0 @@
-package de.siphalor.tweed5.patchwork.impl;
-
-
-import org.jspecify.annotations.Nullable;
-
-public class ByteArrayClassLoader extends ClassLoader {
-	public static Class<?> loadClass(@Nullable String binaryClassName, byte[] byteCode) {
-		return new ByteArrayClassLoader(ByteArrayClassLoader.class.getClassLoader())
-				.createClass(binaryClassName, byteCode);
-	}
-
-	private ByteArrayClassLoader(ClassLoader parent) {
-		super(parent);
-	}
-
-	public Class<?> createClass(@Nullable String binaryClassName, byte[] byteCode) {
-		Class<?> clazz = defineClass(binaryClassName, byteCode, 0, byteCode.length);
-		resolveClass(clazz);
-		return clazz;
-	}
-}

tweed5-patchwork/src/main/java/de/siphalor/tweed5/patchwork/impl/PatchworkClass.java

@@ -1,18 +0,0 @@
-package de.siphalor.tweed5.patchwork.impl;
-
-import de.siphalor.tweed5.patchwork.api.Patchwork;
-import lombok.Builder;
-import lombok.Value;
-
-import java.lang.invoke.MethodHandle;
-import java.util.Collection;
-
-@Value
-@Builder
-public class PatchworkClass<P extends Patchwork<P>> {
-	String classPackage;
-	String className;
-	Class<P> theClass;
-	MethodHandle constructor;
-	Collection<PatchworkClassPart> parts;
-}

tweed5-patchwork/src/main/java/de/siphalor/tweed5/patchwork/impl/PatchworkClassGenerator.java

@@ -1,653 +0,0 @@
-package de.siphalor.tweed5.patchwork.impl;
-
-import de.siphalor.tweed5.patchwork.api.Patchwork;
-import de.siphalor.tweed5.patchwork.api.PatchworkPartIsNullException;
-import de.siphalor.tweed5.patchwork.impl.util.StreamUtils;
-import lombok.*;
-import org.jspecify.annotations.NonNull;
-import org.jspecify.annotations.Nullable;
-import org.objectweb.asm.*;
-import org.objectweb.asm.commons.GeneratorAdapter;
-
-import java.io.IOException;
-import java.lang.reflect.Method;
-import java.lang.reflect.Modifier;
-import java.util.*;
-import java.util.stream.Collectors;
-import java.util.stream.Stream;
-
-@Getter
-public class PatchworkClassGenerator {
-	/**
-	 * Class version to use (Java 8)
-	 */
-	private static final int CLASS_VERSION = Opcodes.V1_8;
-
-	private static final String INNER_EQUALS_METHOD_NAME = "patchwork$innerEquals";
-
-	private static String generateUniqueIdentifier() {
-		UUID uuid = UUID.randomUUID();
-		return uuid.toString().replace("-", "");
-	}
-
-	private final Config config;
-	private final Collection<PatchworkClassPart> parts;
-	private final String className;
-	@Getter(AccessLevel.NONE)
-	private final ClassWriter classWriter;
-
-	public PatchworkClassGenerator(Config config, Collection<PatchworkClassPart> parts) {
-		this.config = config;
-		this.parts = parts;
-		className = config.classPrefix() + generateUniqueIdentifier();
-		classWriter = new ClassWriter(ClassWriter.COMPUTE_FRAMES);
-	}
-
-	public String internalClassName() {
-		return config.classPackage().replace('.', '/') + "/" + className();
-	}
-
-	public String binaryClassName() {
-		return config.classPackage() + "." + className();
-	}
-
-	public void verify() throws VerificationException {
-		for (PatchworkClassPart part : parts) {
-			verifyClass(part.partInterface());
-		}
-		verifyPartMethods();
-	}
-
-	private void verifyClass(Class<?> partClass) throws InvalidPatchworkPartClassException {
-		if (!partClass.isInterface()) {
-			throw new InvalidPatchworkPartClassException(partClass, "Must be an interface");
-		}
-		if ((partClass.getModifiers() & Modifier.PUBLIC) == 0) {
-			throw new InvalidPatchworkPartClassException(partClass, "Interface must be public");
-		}
-	}
-
-	private void verifyPartMethods() throws DuplicateMethodsException {
-		Map<MethodDescriptor, Collection<Method>> methodsBySignature = new HashMap<>();
-
-		for (PatchworkClassPart patchworkPart : parts) {
-			for (Method method : patchworkPart.partInterface().getMethods()) {
-				MethodDescriptor signature = new MethodDescriptor(method.getName(), method.getParameterTypes());
-
-				methodsBySignature
-						.computeIfAbsent(signature, s -> new ArrayList<>())
-						.add(method);
-			}
-		}
-
-		List<Method> duplicateMethods = methodsBySignature.entrySet().stream()
-				.filter(entry -> entry.getValue().size() > 1)
-				.flatMap(entry -> entry.getValue().stream())
-				.collect(Collectors.toList());
-
-		if (!duplicateMethods.isEmpty()) {
-			throw new DuplicateMethodsException(duplicateMethods);
-		}
-	}
-
-	public void generate() throws GenerationException {
-		beginClass();
-		generateSimpleConstructor();
-		for (PatchworkClassPart extensionClass : parts) {
-			addPart(extensionClass);
-		}
-		appendPojoMethods();
-		appendDefaultPatchworkMethods();
-		classWriter.visitEnd();
-	}
-
-	public byte[] emit() {
-		return classWriter.toByteArray();
-	}
-
-	private void beginClass() {
-		String[] interfaces = StreamUtils.concat(
-				Stream.of(Type.getInternalName(Patchwork.class)),
-				config.markerInterfaces().stream().map(Type::getInternalName),
-				parts.stream().map(ext -> Type.getInternalName(ext.partInterface()))
-		).toArray(String[]::new);
-
-		classWriter.visit(
-				CLASS_VERSION,
-				Opcodes.ACC_PUBLIC | Opcodes.ACC_SYNTHETIC | Opcodes.ACC_FINAL,
-				internalClassName(),
-				null,
-				Type.getInternalName(Object.class),
-				interfaces
-		);
-	}
-
-	private void generateSimpleConstructor() {
-		MethodVisitor methodWriter = classWriter.visitMethod(Opcodes.ACC_PUBLIC, "<init>", "()V", null, null);
-		methodWriter.visitCode();
-		methodWriter.visitVarInsn(Opcodes.ALOAD, 0);
-		methodWriter.visitMethodInsn(Opcodes.INVOKESPECIAL, "java/lang/Object", "<init>", "()V", false);
-		methodWriter.visitInsn(Opcodes.RETURN);
-		methodWriter.visitMaxs(1, 1);
-		methodWriter.visitEnd();
-	}
-
-	private void appendPojoMethods() {
-		appendEqualsMethod();
-		appendHashCodeMethod();
-		appendToStringMethod();
-	}
-
-	// <editor-fold desc="POJO Methods">
-	private void appendEqualsMethod() {
-		appendInnerEqualsMethod();
-
-		GeneratorAdapter methodWriter = createMethod(
-				Opcodes.ACC_PUBLIC,
-				"equals",
-				"(Ljava/lang/Object;)Z",
-				null,
-				null
-		);
-		methodWriter.visitParameter("other", Opcodes.ACC_FINAL);
-		methodWriter.visitCode();
-
-
-		Label falseLabel = methodWriter.newLabel();
-		Label continueLabel = methodWriter.newLabel();
-
-		methodWriter.loadArg(0);
-		methodWriter.loadThis();
-		methodWriter.visitJumpInsn(Opcodes.IF_ACMPNE, continueLabel);
-		methodWriter.push(true);
-		methodWriter.returnValue();
-
-		methodWriter.visitLabel(continueLabel);
-		methodWriter.loadArg(0);
-		methodWriter.visitTypeInsn(Opcodes.INSTANCEOF, internalClassName());
-		methodWriter.visitJumpInsn(Opcodes.IFEQ, falseLabel);
-
-		methodWriter.loadArg(0);
-		methodWriter.visitTypeInsn(Opcodes.CHECKCAST, internalClassName());
-		methodWriter.loadThis();
-		methodWriter.visitMethodInsn(
-				Opcodes.INVOKESPECIAL,
-				internalClassName(),
-				INNER_EQUALS_METHOD_NAME,
-				"(L" + internalClassName() + ";)Z",
-				false
-		);
-		methodWriter.visitJumpInsn(Opcodes.IFEQ, falseLabel);
-
-		methodWriter.push(true);
-		methodWriter.returnValue();
-
-		methodWriter.visitLabel(falseLabel);
-		methodWriter.push(false);
-		methodWriter.returnValue();
-
-		methodWriter.visitMaxs(0, 0);
-		methodWriter.visitEnd();
-	}
-
-	private void appendInnerEqualsMethod() {
-		GeneratorAdapter methodWriter = createMethod(
-				Opcodes.ACC_PRIVATE,
-				INNER_EQUALS_METHOD_NAME,
-				"(L" + internalClassName() + ";)Z",
-				null,
-				null
-		);
-
-		methodWriter.visitParameter("other", Opcodes.ACC_FINAL);
-		methodWriter.visitCode();
-
-		Label falseLabel = methodWriter.newLabel();
-		for (PatchworkClassPart part : parts) {
-			methodWriter.loadArg(0);
-			visitFieldInsn(methodWriter, part, Opcodes.GETFIELD);
-			methodWriter.loadThis();
-			visitFieldInsn(methodWriter, part, Opcodes.GETFIELD);
-			methodWriter.visitMethodInsn(
-					Opcodes.INVOKESTATIC,
-					Type.getInternalName(Objects.class),
-					"equals",
-					"(Ljava/lang/Object;Ljava/lang/Object;)Z",
-					false
-			);
-			methodWriter.visitJumpInsn(Opcodes.IFEQ, falseLabel);
-		}
-
-		methodWriter.push(true);
-		methodWriter.returnValue();
-
-		methodWriter.visitLabel(falseLabel);
-		methodWriter.push(false);
-		methodWriter.returnValue();
-
-		methodWriter.visitMaxs(0, 0);
-		methodWriter.visitEnd();
-	}
-
-	private void appendHashCodeMethod() {
-		GeneratorAdapter methodWriter = createMethod(
-				Opcodes.ACC_PUBLIC,
-				"hashCode",
-				"()I",
-				null,
-				null
-		);
-
-		methodWriter.visitCode();
-
-		methodWriter.push(parts.size());
-		methodWriter.newArray(Type.getType(Object.class));
-
-		int i = 0;
-		for (PatchworkClassPart part : parts) {
-			methodWriter.dup();
-			methodWriter.push(i);
-
-			methodWriter.loadThis();
-			visitFieldInsn(methodWriter, part, Opcodes.GETFIELD);
-
-			methodWriter.visitInsn(Opcodes.AASTORE);
-
-			i++;
-		}
-
-		methodWriter.visitMethodInsn(
-				Opcodes.INVOKESTATIC,
-				"java/util/Objects",
-				"hash",
-				"([Ljava/lang/Object;)I",
-				false
-		);
-
-		methodWriter.returnValue();
-
-		methodWriter.visitMaxs(0, 0);
-		methodWriter.visitEnd();
-	}
-
-	private void appendToStringMethod() {
-		GeneratorAdapter methodWriter = createMethod(
-				Opcodes.ACC_PUBLIC,
-				"toString",
-				"()Ljava/lang/String;",
-				null,
-				null
-		);
-
-		methodWriter.visitCode();
-
-		String stringBuilderType = Type.getInternalName(StringBuilder.class);
-		methodWriter.visitTypeInsn(Opcodes.NEW, stringBuilderType);
-		methodWriter.dup();
-		methodWriter.push(className().length() + 10 + parts.size() * 64);
-		methodWriter.visitMethodInsn(
-				Opcodes.INVOKESPECIAL,
-				stringBuilderType,
-				"<init>",
-				"(I)V",
-				false
-		);
-
-		StringBuilder constantConcat = new StringBuilder();
-		constantConcat.append(className()).append("{\n");
-
-		for (PatchworkClassPart part : parts) {
-			constantConcat.append("\t").append(part.partInterface().getSimpleName()).append(": ");
-			methodWriter.push(constantConcat.toString());
-			constantConcat.setLength(0);
-			visitStringBuilderAppendString(methodWriter);
-
-			Label nullLabel = methodWriter.newLabel();
-			Label continueLabel = methodWriter.newLabel();
-			methodWriter.loadThis();
-			visitFieldInsn(methodWriter, part, Opcodes.GETFIELD);
-			methodWriter.dup();
-			methodWriter.visitJumpInsn(Opcodes.IFNULL, nullLabel);
-
-			visitToString(methodWriter);
-			methodWriter.visitJumpInsn(Opcodes.GOTO, continueLabel);
-
-			methodWriter.visitLabel(nullLabel);
-			methodWriter.pop();
-			methodWriter.push("<unset>");
-
-			methodWriter.visitLabel(continueLabel);
-			visitStringBuilderAppendString(methodWriter);
-
-			constantConcat.append(",\n");
-		}
-		constantConcat.append("}");
-		methodWriter.push(constantConcat.toString());
-		visitStringBuilderAppendString(methodWriter);
-		visitToString(methodWriter);
-		methodWriter.returnValue();
-
-		methodWriter.visitMaxs(0, 0);
-		methodWriter.visitEnd();
-	}
-	// </editor-fold>
-
-	private void appendDefaultPatchworkMethods() {
-		appendCopyMethod();
-		appendIsPatchworkPartDefinedMethod();
-		appendIsPatchworkPartSetMethod();
-	}
-
-	// <editor-fold desc="Patchwork Methods">
-	private void appendCopyMethod() {
-		GeneratorAdapter methodWriter = createMethod(
-				Opcodes.ACC_PUBLIC,
-				"copy",
-				"()L" + Type.getInternalName(Patchwork.class) + ";",
-				null,
-				null
-		);
-		methodWriter.visitCode();
-		methodWriter.visitTypeInsn(Opcodes.NEW, internalClassName());
-		methodWriter.dup();
-		methodWriter.visitMethodInsn(
-				Opcodes.INVOKESPECIAL,
-				internalClassName(),
-				"<init>",
-				"()V",
-				false
-		);
-		for (PatchworkClassPart part : parts) {
-			methodWriter.dup();
-			methodWriter.loadThis();
-			visitFieldInsn(methodWriter, part, Opcodes.GETFIELD);
-			visitFieldInsn(methodWriter, part, Opcodes.PUTFIELD);
-		}
-		methodWriter.returnValue();
-		methodWriter.visitMaxs(0, 0);
-		methodWriter.visitEnd();
-	}
-
-	private void appendIsPatchworkPartDefinedMethod() {
-		GeneratorAdapter methodWriter = createMethod(
-				Opcodes.ACC_PUBLIC,
-				"isPatchworkPartDefined",
-				"(Ljava/lang/Class;)Z",
-				null,
-				null
-		);
-		methodWriter.visitParameter(null, Opcodes.ACC_FINAL);
-		methodWriter.visitCode();
-		Label trueLabel = methodWriter.newLabel();
-		for (PatchworkClassPart part : parts) {
-			methodWriter.loadArg(0);
-			methodWriter.push(Type.getType(part.partInterface()));
-			methodWriter.ifCmp(Type.getType(Object.class), GeneratorAdapter.EQ, trueLabel);
-		}
-		methodWriter.push(false);
-		methodWriter.returnValue();
-		methodWriter.visitLabel(trueLabel);
-		methodWriter.push(true);
-		methodWriter.returnValue();
-		methodWriter.visitMaxs(0, 0);
-		methodWriter.visitEnd();
-	}
-
-	private void appendIsPatchworkPartSetMethod() {
-		GeneratorAdapter methodWriter = createMethod(
-				Opcodes.ACC_PUBLIC,
-				"isPatchworkPartSet",
-				"(Ljava/lang/Class;)Z",
-				null,
-				null
-		);
-		methodWriter.visitParameter(null, Opcodes.ACC_FINAL);
-		methodWriter.visitCode();
-		Label[] labels = new Label[parts.size()];
-		int i = 0;
-		for (PatchworkClassPart part : parts) {
-			labels[i] = methodWriter.newLabel();
-			methodWriter.loadArg(0);
-			methodWriter.push(Type.getType(part.partInterface()));
-			methodWriter.ifCmp(Type.getType(Object.class), GeneratorAdapter.EQ, labels[i]);
-			i++;
-		}
-		methodWriter.push(false);
-		methodWriter.returnValue();
-
-		Label falseLabel = methodWriter.newLabel();
-		i = 0;
-		for (PatchworkClassPart part : parts) {
-			methodWriter.visitLabel(labels[i]);
-			methodWriter.loadThis();
-			visitFieldInsn(methodWriter, part, Opcodes.GETFIELD);
-			methodWriter.push((String) null);
-			methodWriter.ifCmp(Type.getType(part.partInterface()), GeneratorAdapter.EQ, falseLabel);
-			methodWriter.push(true);
-			methodWriter.returnValue();
-			i++;
-		}
-		methodWriter.visitLabel(falseLabel);
-		methodWriter.push(false);
-		methodWriter.returnValue();
-		methodWriter.visitMaxs(1, 1);
-		methodWriter.visitEnd();
-	}
-
-	public void addPart(PatchworkClassPart patchworkPart) throws GenerationException {
-		patchworkPart.fieldName("f_" + generateUniqueIdentifier());
-
-		classWriter.visitField(
-				Opcodes.ACC_PUBLIC,
-				patchworkPart.fieldName(),
-				patchworkPart.partInterface().descriptorString(),
-				null,
-				null
-		);
-
-		appendPartMethods(patchworkPart);
-	}
-
-	private void appendPartMethods(PatchworkClassPart patchworkPart) throws GenerationException {
-		try {
-			ClassReader classReader = new ClassReader(patchworkPart.partInterface().getName());
-			classReader.accept(new PartClassVisitor(patchworkPart), ClassReader.SKIP_FRAMES);
-		} catch (IOException e) {
-			throw new GenerationException("Failed to read interface class file", e);
-		}
-	}
-	// </editor-fold>
-
-	private GeneratorAdapter createMethod(
-			int access,
-			String name,
-			String desc,
-			@Nullable String signature,
-			String @Nullable [] exceptions
-	) {
-		MethodVisitor methodVisitor = classWriter.visitMethod(access, name, desc, signature, exceptions);
-		return new GeneratorAdapter(methodVisitor, access, name, desc);
-	}
-
-	private void visitFieldInsn(MethodVisitor methodWriter, PatchworkClassPart part, int opcode) {
-		methodWriter.visitFieldInsn(
-				opcode,
-				internalClassName(),
-				part.fieldName(),
-				Type.getDescriptor(part.partInterface())
-		);
-	}
-
-	private static void visitToString(MethodVisitor methodWriter) {
-		methodWriter.visitMethodInsn(
-				Opcodes.INVOKEVIRTUAL,
-				Type.getInternalName(Object.class),
-				"toString",
-				"()Ljava/lang/String;",
-				false
-		);
-	}
-
-	private static void visitStringBuilderAppendString(MethodVisitor methodWriter) {
-		String stringBuilderType = Type.getInternalName(StringBuilder.class);
-		methodWriter.visitMethodInsn(
-				Opcodes.INVOKEVIRTUAL,
-				stringBuilderType,
-				"append",
-				"(Ljava/lang/String;)L" + stringBuilderType + ";",
-				false
-		);
-	}
-
-	private class PartClassVisitor extends ClassVisitor {
-		private final PatchworkClassPart extensionClass;
-
-		protected PartClassVisitor(PatchworkClassPart extensionClass) {
-			super(Opcodes.ASM9);
-			this.extensionClass = extensionClass;
-		}
-
-		@Override
-		public MethodVisitor visitMethod(
-				int access,
-				String name,
-				String descriptor,
-				String signature,
-				String[] exceptions
-		) {
-			GeneratorAdapter methodWriter = createMethod(Opcodes.ACC_PUBLIC, name, descriptor, signature, exceptions);
-			return new PartMethodVisitor(api, methodWriter, descriptor, extensionClass);
-		}
-	}
-
-	private class PartMethodVisitor extends MethodVisitor {
-		private final GeneratorAdapter methodWriter;
-		private final String methodDescriptor;
-		private final PatchworkClassPart patchworkPart;
-
-		protected PartMethodVisitor(
-				int api,
-				GeneratorAdapter methodWriter,
-				String methodDescriptor,
-				PatchworkClassPart patchworkPart
-		) {
-			super(api);
-			this.methodWriter = methodWriter;
-			this.patchworkPart = patchworkPart;
-			this.methodDescriptor = methodDescriptor;
-		}
-
-		@Override
-		public void visitParameter(String name, int access) {
-			methodWriter.visitParameter(name, access);
-		}
-
-		@Override
-		public void visitEnd() {
-			Label nullLabel = methodWriter.newLabel();
-
-			methodWriter.visitCode();
-			methodWriter.visitVarInsn(Opcodes.ALOAD, 0);
-			methodWriter.visitFieldInsn(
-					Opcodes.GETFIELD,
-					internalClassName(),
-					patchworkPart.fieldName(),
-					Type.getDescriptor(patchworkPart.partInterface())
-			);
-			methodWriter.dup();
-			methodWriter.ifNull(nullLabel);
-			methodWriter.loadArgs();
-			methodWriter.visitMethodInsn(
-					Opcodes.INVOKEINTERFACE,
-					Type.getInternalName(patchworkPart.partInterface()),
-					methodWriter.getName(),
-					methodDescriptor,
-					true
-			);
-			methodWriter.returnValue();
-			methodWriter.visitLabel(nullLabel);
-			methodWriter.pop();
-			methodWriter.throwException(
-					Type.getType(PatchworkPartIsNullException.class),
-					"The patchwork part " + patchworkPart.partInterface().getSimpleName() + " has not been set"
-			);
-
-			methodWriter.visitMaxs(-1, -1);
-			methodWriter.visitEnd();
-		}
-	}
-
-	@Value
-	private static class MethodDescriptor {
-		String name;
-		Class<?>[] parameterTypes;
-	}
-
-	@Data
-	public static class Config {
-		@lombok.NonNull
-		private @NonNull String classPackage;
-		private String classPrefix = "";
-		private Collection<Class<?>> markerInterfaces = Collections.emptyList();
-	}
-
-	public static class VerificationException extends Exception {
-		private VerificationException(String message) {
-			super(message);
-		}
-	}
-
-	@Value
-	@EqualsAndHashCode(callSuper = true)
-	public static class InvalidPatchworkPartClassException extends VerificationException {
-		Class<?> partClass;
-
-		public InvalidPatchworkPartClassException(Class<?> partClass, String message) {
-			super("Invalid patchwork part class " + partClass.getName() + ": " + message);
-			this.partClass = partClass;
-		}
-
-		@Override
-		public String toString() {
-			return super.toString();
-		}
-	}
-
-	@Value
-	@EqualsAndHashCode(callSuper = true)
-	public static class DuplicateMethodsException extends VerificationException {
-		transient Collection<Method> signatures;
-
-		private DuplicateMethodsException(Collection<Method> methods) {
-			super("Duplicate method signatures:\n" + methods.stream()
-					.map(DuplicateMethodsException::getMethodMessage)
-					.collect(Collectors.joining("\n")));
-			this.signatures = methods;
-		}
-
-		private static String getMethodMessage(Method method) {
-			StringBuilder stringBuilder = new StringBuilder("\t- "
-					+ method.getDeclaringClass().getCanonicalName()
-					+ "#(");
-			for (Class<?> parameterType : method.getParameterTypes()) {
-				stringBuilder.append(parameterType.getCanonicalName());
-				stringBuilder.append(", ");
-			}
-			stringBuilder.append(")");
-			stringBuilder.append(method.getReturnType().getCanonicalName());
-			stringBuilder.append("\n");
-			return stringBuilder.toString();
-		}
-
-		@Override
-		public String toString() {
-			return super.toString();
-		}
-	}
-
-	public static class GenerationException extends Exception {
-		public GenerationException(String message, Throwable cause) {
-			super(message, cause);
-		}
-	}
-}

tweed5-patchwork/src/main/java/de/siphalor/tweed5/patchwork/impl/PatchworkClassPart.java

@@ -1,12 +0,0 @@
-package de.siphalor.tweed5.patchwork.impl;
-
-import lombok.Data;
-
-import java.lang.invoke.MethodHandle;
-
-@Data
-public class PatchworkClassPart {
-	private final Class<?> partInterface;
-	private String fieldName;
-	private MethodHandle fieldSetter;
-}

tweed5-patchwork/src/main/java/de/siphalor/tweed5/patchwork/impl/PatchworkFactoryImpl.java

@@ -0,0 +1,100 @@
+package de.siphalor.tweed5.patchwork.impl;
+
+import de.siphalor.tweed5.patchwork.api.InvalidPatchworkAccessException;
+import de.siphalor.tweed5.patchwork.api.Patchwork;
+import de.siphalor.tweed5.patchwork.api.PatchworkFactory;
+import de.siphalor.tweed5.patchwork.api.PatchworkPartAccess;
+import lombok.AccessLevel;
+import lombok.EqualsAndHashCode;
+import lombok.RequiredArgsConstructor;
+import org.jspecify.annotations.Nullable;
+
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.List;
+import java.util.UUID;
+
+@RequiredArgsConstructor(access = AccessLevel.PRIVATE)
+public class PatchworkFactoryImpl implements PatchworkFactory {
+	private final UUID factoryUuid;
+	private final Class<?>[] partClasses;
+
+	@Override
+	public Patchwork create() {
+		return new PatchworkImpl(new Object[partClasses.length]);
+	}
+
+	public static class Builder implements PatchworkFactory.Builder {
+		private final UUID factoryUuid = UUID.randomUUID();
+		private final List<Class<?>> partClasses = new ArrayList<>();
+		private boolean built;
+
+		@Override
+		public <T> PatchworkPartAccess<T> registerPart(Class<T> partClass) {
+			requireFresh();
+			partClasses.add(partClass);
+			return new PartAccessImpl<>(factoryUuid, partClasses.size() - 1);
+		}
+
+		@Override
+		public PatchworkFactory build() {
+			requireFresh();
+			built = true;
+			return new PatchworkFactoryImpl(factoryUuid, partClasses.toArray(new Class<?>[0]));
+		}
+
+		private void requireFresh() {
+			if (built) {
+				throw new IllegalStateException("Builder has already been used.");
+			}
+		}
+	}
+
+	@RequiredArgsConstructor
+	private static class PartAccessImpl<T extends @Nullable Object> implements PatchworkPartAccess<T> {
+		private final UUID factoryUuid;
+		private final int partIndex;
+	}
+
+	@RequiredArgsConstructor
+	@EqualsAndHashCode
+	private class PatchworkImpl implements Patchwork {
+		private final @Nullable Object[] partValues;
+
+		@Override
+		public <T extends @Nullable Object> T get(PatchworkPartAccess<T> access) throws InvalidPatchworkAccessException {
+			PartAccessImpl<T> castedAccess = validatePartAccess(access);
+			//noinspection unchecked
+			return (T) partValues[castedAccess.partIndex];
+		}
+
+		@Override
+		public <T extends @Nullable Object> void set(PatchworkPartAccess<T> access, T value) throws InvalidPatchworkAccessException {
+			PartAccessImpl<T> castedAccess = validatePartAccess(access);
+
+			if (value != null && !partClasses[castedAccess.partIndex].isInstance(value)) {
+				throw new IllegalArgumentException(
+						"value " + value + " of type " + value.getClass().getName() +
+								" doesn't match registered value class " + partClasses[castedAccess.partIndex].getName()
+				);
+			}
+
+			partValues[castedAccess.partIndex] = value;
+		}
+
+		private <T extends @Nullable Object> PartAccessImpl<T> validatePartAccess(PatchworkPartAccess<T> access)
+				throws InvalidPatchworkAccessException {
+			if (!(access instanceof PartAccessImpl<?>)) {
+				throw new InvalidPatchworkAccessException("Part access is of incorrect class.");
+			} else if (((PartAccessImpl<?>) access).factoryUuid != factoryUuid) {
+				throw new InvalidPatchworkAccessException("Part access does not belong to the same patchwork factory.");
+			}
+			return (PartAccessImpl<T>) access;
+		}
+
+		@Override
+		public Patchwork copy() {
+			return new PatchworkImpl(Arrays.copyOf(partValues, partValues.length));
+		}
+	}
+}

tweed5-patchwork/src/main/java/de/siphalor/tweed5/patchwork/impl/util/StreamUtils.java

@@ -1,14 +0,0 @@
-package de.siphalor.tweed5.patchwork.impl.util;
-
-import java.util.stream.Stream;
-
-public class StreamUtils {
-	@SafeVarargs
-	public static <T> Stream<T> concat(Stream<T>... streams) {
-		Stream<T> result = Stream.empty();
-		for (Stream<T> stream : streams) {
-			result = Stream.concat(result, stream);
-		}
-		return result;
-	}
-}

tweed5-patchwork/src/test/java/de/siphalor/tweed5/patchwork/impl/PatchworkClassGeneratorGeneratedClassTest.java

@@ -1,269 +0,0 @@
-package de.siphalor.tweed5.patchwork.impl;
-
-import de.siphalor.tweed5.patchwork.api.Patchwork;
-import de.siphalor.tweed5.patchwork.api.PatchworkPartIsNullException;
-import lombok.Data;
-import lombok.experimental.Accessors;
-import org.junit.jupiter.api.BeforeEach;
-import org.junit.jupiter.api.Disabled;
-import org.junit.jupiter.api.Test;
-
-import java.io.File;
-import java.io.IOException;
-import java.io.OutputStream;
-import java.lang.reflect.Constructor;
-import java.lang.reflect.Field;
-import java.nio.file.Files;
-import java.nio.file.Path;
-import java.util.Arrays;
-import java.util.Collections;
-
-import static org.junit.jupiter.api.Assertions.*;
-
-class PatchworkClassGeneratorGeneratedClassTest {
-
-	PatchworkClassPart partA;
-	PatchworkClassPart partB;
-
-	byte[] bytes;
-	Class<Patchwork<?>> patchworkClass;
-	Patchwork<?> patchwork;
-
-	@BeforeEach
-	void setUp() {
-		partA = new PatchworkClassPart(ExtensionA.class);
-		partB = new PatchworkClassPart(ExtensionB.class);
-		PatchworkClassGenerator generator = new PatchworkClassGenerator(
-				new PatchworkClassGenerator.Config("de.siphalor.tweed5.core.test")
-						.classPrefix("FullTest$")
-						.markerInterfaces(Collections.singletonList(MarkerInterface.class)),
-				Arrays.asList(partA, partB)
-		);
-
-		assertDoesNotThrow(generator::verify);
-		assertDoesNotThrow(generator::generate);
-
-		bytes = generator.emit();
-		//noinspection unchecked
-		patchworkClass = (Class<Patchwork<?>>) assertDoesNotThrow(() -> ByteArrayClassLoader.loadClass(null, bytes));
-
-		patchwork = createPatchworkInstance();
-	}
-
-	@Test
-	@Disabled("Dumping the class is only for testing purposes")
-	void dumpClass() {
-		try {
-			Path target = File.createTempFile("tweed5-patchwork", ".class").toPath();
-			try (OutputStream os = Files.newOutputStream(target)) {
-				os.write(bytes);
-			}
-			System.out.println("Dumped generated class to " + target);
-
-		} catch (IOException e) {
-			assertNull(e, "Must not throw exception");
-		}
-	}
-
-	@Test
-	void packageName() {
-		assertEquals("de.siphalor.tweed5.core.test", patchworkClass.getPackage().getName());
-	}
-
-	@Test
-	void className() {
-		assertTrue(patchworkClass.getSimpleName().startsWith("FullTest$"), "Generated class name must start with prefix FullTest$, got " + patchworkClass.getSimpleName());
-	}
-
-	@Test
-	void implementsInterfaces() {
-		assertImplements(MarkerInterface.class, patchworkClass);
-		assertImplements(Patchwork.class, patchworkClass);
-		assertImplements(ExtensionA.class, patchworkClass);
-		assertImplements(ExtensionB.class, patchworkClass);
-	}
-
-	@Test
-	void toStringMethod() {
-		int defaultHashCode = System.identityHashCode(patchwork);
-		String stringResult = patchwork.toString();
-		assertFalse(stringResult.contains(Integer.toHexString(defaultHashCode)), "Expected toString not to be the default toString, got: " + stringResult);
-	}
-
-	@Test
-	void toStringContent() {
-		setFieldValue(patchwork, partA.fieldName(), new ExtensionAImpl());
-		((ExtensionA) patchwork).setText("Hello World!");
-		String stringResult = patchwork.toString();
-		assertTrue(stringResult.contains("Hello World!"), "Expected toString to contain the toString of its extensions, got: " + stringResult);
-	}
-
-	@Test
-	void hashCodeMethod() {
-		int emptyHashCode = patchwork.hashCode();
-
-		setFieldValue(patchwork, partA.fieldName(), new ExtensionAImpl());
-		int hashCodeWithA = patchwork.hashCode();
-
-		((ExtensionA) patchwork).setText("Hello World!");
-		int hashCodeWithAContent = patchwork.hashCode();
-
-		assertNotEquals(emptyHashCode, hashCodeWithA, "Expected hashCode to be different, got: " + emptyHashCode + " and " + hashCodeWithA);
-		assertNotEquals(emptyHashCode, hashCodeWithAContent, "Expected hashCode to be different, got: " + emptyHashCode + " and " + hashCodeWithAContent);
-		assertNotEquals(hashCodeWithA, hashCodeWithAContent, "Expected hashCode to be different, got: " + hashCodeWithA + " and " + hashCodeWithAContent);
-	}
-
-	@SuppressWarnings("SimplifiableAssertion")
-	@Test
-	void equalsMethod() {
-		//noinspection ConstantValue,SimplifiableAssertion
-		assertFalse(patchwork.equals(null));
-
-		//noinspection EqualsWithItself
-		assertTrue(patchwork.equals(patchwork));
-
-		Patchwork<?> other = createPatchworkInstance();
-		assertTrue(patchwork.equals(other));
-		assertTrue(other.equals(patchwork));
-
-		setFieldValue(patchwork, partA.fieldName(), new ExtensionAImpl());
-		assertFalse(patchwork.equals(other));
-
-		setFieldValue(other, partA.fieldName(), new ExtensionAImpl());
-		assertTrue(patchwork.equals(other));
-		assertTrue(other.equals(patchwork));
-
-		((ExtensionA) patchwork).setText("Hello 1!");
-		((ExtensionA) other).setText("Hello 2!");
-		assertFalse(patchwork.equals(other));
-	}
-
-	@Test
-	void copy() {
-		ExtensionAImpl aImpl = new ExtensionAImpl();
-		setFieldValue(patchwork, partA.fieldName(), aImpl);
-
-		Patchwork<?> copy = patchwork.copy();
-		Object aValue = getFieldValue(copy, partA.fieldName());
-		Object bValue = getFieldValue(copy, partB.fieldName());
-
-		assertSame(aImpl, aValue);
-		assertNull(bValue);
-	}
-
-	@Test
-	void isPartDefined() {
-		assertPartDefined(ExtensionA.class, patchwork);
-		assertPartDefined(ExtensionB.class, patchwork);
-		assertPartUndefined(ExtensionC.class, patchwork);
-	}
-
-	static void assertPartDefined(Class<?> anInterface, Patchwork<?> patchwork) {
-		assertTrue(patchwork.isPatchworkPartDefined(anInterface), "Patchwork part " + anInterface.getName() + " must be defined");
-	}
-
-	static void assertPartUndefined(Class<?> anInterface, Patchwork<?> patchwork) {
-		assertFalse(patchwork.isPatchworkPartDefined(anInterface), "Patchwork part " + anInterface.getName() + " must not be defined");
-	}
-
-	@Test
-	void checkFieldsExist() {
-		assertFieldExists(partA.fieldName(), ExtensionA.class);
-		assertFieldExists(partB.fieldName(), ExtensionB.class);
-	}
-
-	void assertFieldExists(String fieldName, Class<?> fieldType) {
-		Field field = getField(fieldName);
-		assertEquals(fieldType, field.getType());
-	}
-
-	@Test
-	void isPartSet() {
-		assertPartUnset(ExtensionA.class, patchwork);
-		assertPartUnset(ExtensionB.class, patchwork);
-		assertPartUnset(ExtensionC.class, patchwork);
-
-		setFieldValue(patchwork, partA.fieldName(), new ExtensionAImpl());
-
-		assertPartSet(ExtensionA.class, patchwork);
-		assertPartUnset(ExtensionB.class, patchwork);
-		assertPartUnset(ExtensionC.class, patchwork);
-
-		setFieldValue(patchwork, partB.fieldName(), new ExtensionBImpl());
-
-		assertPartSet(ExtensionA.class, patchwork);
-		assertPartSet(ExtensionB.class, patchwork);
-		assertPartUnset(ExtensionC.class, patchwork);
-	}
-
-	@Test
-	void inheritedMethodCalls() {
-		assertThrows(PatchworkPartIsNullException.class, () -> ((ExtensionA) patchwork).getText());
-		assertThrows(PatchworkPartIsNullException.class, () -> ((ExtensionB) patchwork).multiply(1, 2));
-
-		setFieldValue(patchwork, partA.fieldName(), new ExtensionAImpl());
-		setFieldValue(patchwork, partB.fieldName(), new ExtensionBImpl());
-
-		assertEquals(6, assertDoesNotThrow(() -> ((ExtensionB) patchwork).multiply(2, 3)), "Method of extension b must be working");
-
-		assertDoesNotThrow(() -> ((ExtensionA) patchwork).setText("something"));
-		assertEquals("something", ((ExtensionA) patchwork).getText());
-	}
-
-	Patchwork<?> createPatchworkInstance() {
-		Constructor<?> constructor = assertDoesNotThrow(() -> patchworkClass.getConstructor(), "The generated class' constructor must be accessible");
-		return assertDoesNotThrow(() -> (Patchwork<?>) constructor.newInstance());
-	}
-
-	Object getFieldValue(Patchwork<?> patchwork, String fieldName) {
-		return assertDoesNotThrow(() -> getField(fieldName).get(patchwork));
-	}
-
-	void setFieldValue(Patchwork<?> patchwork, String fieldName, Object value) {
-		assertDoesNotThrow(() -> getField(fieldName).set(patchwork, value), "Field " + fieldName + " must be accessible");
-	}
-
-	Field getField(String fieldName) {
-		return assertDoesNotThrow(() -> patchworkClass.getField(fieldName), "Field " + fieldName + " must exist and be public");
-	}
-
-	static void assertPartSet(Class<?> anInterface, Patchwork<?> patchwork) {
-		assertTrue(patchwork.isPatchworkPartSet(anInterface), "Patchwork part " + anInterface.getName() + " must be set");
-	}
-
-	static void assertPartUnset(Class<?> anInterface, Patchwork<?> patchwork) {
-		assertFalse(patchwork.isPatchworkPartSet(anInterface), "Patchwork part " + anInterface.getName() + " must not be set");
-	}
-
-	static void assertImplements(Class<?> anInterface, Class<?> theClass) {
-		assertTrue(anInterface.isAssignableFrom(theClass), "Class " + theClass.getName() + " must implement " + anInterface.getName());
-	}
-
-	public interface MarkerInterface {}
-
-	public interface ExtensionA {
-		String getText();
-
-		void setText(String text);
-	}
-
-	@Data
-	@Accessors(fluent = false)
-	static class ExtensionAImpl implements ExtensionA {
-		private String text;
-	}
-
-	public interface ExtensionB {
-		int multiply(int a, int b);
-	}
-
-	static class ExtensionBImpl implements ExtensionB {
-		public int multiply(int a, int b) {
-			return a * b;
-		}
-	}
-
-	public interface ExtensionC {
-		void test();
-	}
-}

tweed5-patchwork/src/test/java/de/siphalor/tweed5/patchwork/impl/PatchworkClassGeneratorTest.java

@@ -1,52 +0,0 @@
-package de.siphalor.tweed5.patchwork.impl;
-
-import org.junit.jupiter.api.Test;
-
-import java.util.Arrays;
-import java.util.Collection;
-import java.util.Collections;
-import java.util.stream.Collectors;
-
-import static org.junit.jupiter.api.Assertions.assertThrows;
-
-class PatchworkClassGeneratorTest {
-
-	@Test
-	void notAnInterface() {
-		PatchworkClassGenerator generator = createGenerator(Collections.singletonList(NotAnInterface.class));
-		assertThrows(PatchworkClassGenerator.VerificationException.class, generator::verify);
-	}
-
-	@Test
-	void nonPublicInterface() {
-		PatchworkClassGenerator generator = createGenerator(Collections.singletonList(NonPublicInterface.class));
-		assertThrows(PatchworkClassGenerator.VerificationException.class, generator::verify);
-	}
-
-	@Test
-	void duplicateFields() {
-		PatchworkClassGenerator generator = createGenerator(Arrays.asList(DuplicateA.class, DuplicateB.class));
-		assertThrows(PatchworkClassGenerator.VerificationException.class, generator::verify);
-	}
-
-	PatchworkClassGenerator createGenerator(Collection<Class<?>> partClasses) {
-		return new PatchworkClassGenerator(
-				new PatchworkClassGenerator.Config("de.siphalor.tweed5.patchwork.test.generated"),
-				partClasses.stream().map(PatchworkClassPart::new).collect(Collectors.toList())
-		);
-	}
-
-	public static class NotAnInterface {
-	}
-
-	interface NonPublicInterface {
-	}
-
-	public interface DuplicateA {
-		void test();
-	}
-
-	public interface DuplicateB {
-		void test();
-	}
-}

tweed5-patchwork/src/test/java/de/siphalor/tweed5/patchwork/impl/PatchworkFactoryImplTest.java

@@ -0,0 +1,94 @@
+package de.siphalor.tweed5.patchwork.impl;
+
+import de.siphalor.tweed5.patchwork.api.InvalidPatchworkAccessException;
+import de.siphalor.tweed5.patchwork.api.Patchwork;
+import de.siphalor.tweed5.patchwork.api.PatchworkFactory;
+import de.siphalor.tweed5.patchwork.api.PatchworkPartAccess;
+import org.jspecify.annotations.Nullable;
+import org.junit.jupiter.api.Test;
+
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.assertj.core.api.Assertions.assertThatThrownBy;
+
+class PatchworkFactoryImplTest {
+	@Test
+	void test() {
+		PatchworkFactoryImpl.Builder builder = new PatchworkFactoryImpl.Builder();
+		PatchworkPartAccess<String> stringAccess1 = builder.registerPart(String.class);
+		PatchworkPartAccess<@Nullable Number> integerAccess1 = builder.registerPart(Number.class);
+		PatchworkPartAccess<String> stringAccess2 = builder.registerPart(String.class);
+		PatchworkFactory factory = builder.build();
+
+		Patchwork patchwork = factory.create();
+
+		assertThat(patchwork.get(stringAccess1)).isNull();
+		assertThat(patchwork.get(integerAccess1)).isNull();
+		assertThat(patchwork.get(stringAccess2)).isNull();
+
+		patchwork.set(stringAccess1, "Hello");
+		patchwork.set(stringAccess2, "World");
+		patchwork.set(integerAccess1, 123);
+
+		assertThat(patchwork.get(stringAccess1)).isEqualTo("Hello");
+		assertThat(patchwork.get(integerAccess1)).isEqualTo(123);
+		assertThat(patchwork.get(stringAccess2)).isEqualTo("World");
+
+		patchwork.set(integerAccess1, null);
+		assertThat(patchwork.get(integerAccess1)).isNull();
+	}
+
+	@Test
+	void copy() {
+		PatchworkFactoryImpl.Builder builder = new PatchworkFactoryImpl.Builder();
+		PatchworkPartAccess<String> stringAccess = builder.registerPart(String.class);
+		PatchworkFactory factory = builder.build();
+
+		Patchwork patchwork = factory.create();
+		patchwork.set(stringAccess, "Hello");
+
+		Patchwork copy = patchwork.copy();
+		assertThat(copy.get(stringAccess)).isEqualTo("Hello");
+		assertThat(copy).isEqualTo(patchwork);
+	}
+
+	@Test
+	void lateRegister() {
+		PatchworkFactoryImpl.Builder builder = new PatchworkFactoryImpl.Builder();
+		builder.build();
+		assertThatThrownBy(() -> builder.registerPart(String.class)).isInstanceOf(IllegalStateException.class);
+	}
+
+	@Test
+	void doubleBuild() {
+		PatchworkFactoryImpl.Builder builder = new PatchworkFactoryImpl.Builder();
+		builder.build();
+		assertThatThrownBy(builder::build).isInstanceOf(IllegalStateException.class);
+	}
+
+	@Test
+	void invalidAccess() {
+		PatchworkFactoryImpl.Builder builder = new PatchworkFactoryImpl.Builder();
+		builder.registerPart(String.class);
+		PatchworkFactory factory = builder.build();
+
+		Patchwork patchwork = factory.create();
+
+		PatchworkFactoryImpl.Builder otherBuilder = new PatchworkFactoryImpl.Builder();
+		PatchworkPartAccess<String> otherAccess = otherBuilder.registerPart(String.class);
+		otherBuilder.build();
+
+		assertThatThrownBy(() -> patchwork.get(otherAccess)).isInstanceOf(InvalidPatchworkAccessException.class);
+		assertThatThrownBy(() -> patchwork.set(otherAccess, "Hello")).isInstanceOf(InvalidPatchworkAccessException.class);
+	}
+
+	@Test
+	void setWrongType() {
+		PatchworkFactoryImpl.Builder builder = new PatchworkFactoryImpl.Builder();
+		//noinspection unchecked
+		PatchworkPartAccess<Object> access = ((PatchworkPartAccess<Object>)(Object) builder.registerPart(String.class));
+		PatchworkFactory factory = builder.build();
+
+		Patchwork patchwork = factory.create();
+		assertThatThrownBy(() -> patchwork.set(access, 123)).isInstanceOf(IllegalArgumentException.class);
+	}
+}

tweed5-serde-extension/src/main/java/de/siphalor/tweed5/data/extension/api/EntryReaderWriterDefinition.java

@@ -1,6 +0,0 @@
-package de.siphalor.tweed5.data.extension.api;
-
-public interface EntryReaderWriterDefinition {
-	TweedEntryReader<?, ?> reader();
-	TweedEntryWriter<?, ?> writer();
-}

tweed5-serde-extension/src/main/java/de/siphalor/tweed5/data/extension/api/ReadWriteEntryDataExtension.java

@@ -1,6 +0,0 @@
-package de.siphalor.tweed5.data.extension.api;
-
-public interface ReadWriteEntryDataExtension {
-	TweedEntryReader<?, ?> entryReaderChain();
-	TweedEntryWriter<?, ?> entryWriterChain();
-}

tweed5-serde-extension/src/main/java/de/siphalor/tweed5/data/extension/api/ReadWriteExtension.java

@@ -2,29 +2,120 @@ package de.siphalor.tweed5.data.extension.api;
 
 import de.siphalor.tweed5.core.api.entry.ConfigEntry;
 import de.siphalor.tweed5.core.api.extension.TweedExtension;
-import de.siphalor.tweed5.data.extension.api.extension.ReadWriteContextExtensionsData;
+import de.siphalor.tweed5.data.extension.api.readwrite.TweedEntryReaderWriter;
 import de.siphalor.tweed5.data.extension.impl.ReadWriteExtensionImpl;
 import de.siphalor.tweed5.dataapi.api.TweedDataReader;
 import de.siphalor.tweed5.dataapi.api.TweedDataVisitor;
+import de.siphalor.tweed5.patchwork.api.Patchwork;
 import org.jspecify.annotations.Nullable;
 
+import java.util.function.Consumer;
+import java.util.function.Function;
+
 public interface ReadWriteExtension extends TweedExtension {
 	Class<? extends ReadWriteExtension> DEFAULT = ReadWriteExtensionImpl.class;
 
-	void setEntryReaderWriterDefinition(ConfigEntry<?> entry, EntryReaderWriterDefinition readerWriterDefinition);
+	static <T> Consumer<ConfigEntry<T>> entryReaderWriter(
+			TweedEntryReaderWriter<T, ? extends ConfigEntry<T>> entryReaderWriter
+	) {
+		return entryReaderWriter(entryReaderWriter, entryReaderWriter);
+	}
 
-	ReadWriteContextExtensionsData createReadWriteContextExtensionsData();
+	static <T> Consumer<ConfigEntry<T>> entryReaderWriter(
+			TweedEntryReader<T, ? extends ConfigEntry<T>> entryReader,
+			TweedEntryWriter<T, ? extends ConfigEntry<T>> entryWriter
+	) {
+		return entry -> {
+			ReadWriteExtension extension = entry.container().extension(ReadWriteExtension.class)
+					.orElseThrow(() -> new IllegalStateException("No ReadWriteExtension present"));
+			extension.setEntryReader(entry, entryReader);
+			extension.setEntryWriter(entry, entryWriter);
+		};
+	}
 
-	<T extends @Nullable Object> T read(
+	static <T> Consumer<ConfigEntry<T>> entryReader(TweedEntryReader<T, ? extends ConfigEntry<T>> entryReader) {
+		return entry -> {
+			ReadWriteExtension extension = entry.container().extension(ReadWriteExtension.class)
+					.orElseThrow(() -> new IllegalStateException("No ReadWriteExtension present"));
+			extension.setEntryReader(entry, entryReader);
+		};
+	}
+
+	static <T> Consumer<ConfigEntry<T>> entryWriter(TweedEntryWriter<T, ? extends ConfigEntry<T>> entryWriter) {
+		return entry -> {
+			ReadWriteExtension extension = entry.container().extension(ReadWriteExtension.class)
+					.orElseThrow(() -> new IllegalStateException("No ReadWriteExtension present"));
+			extension.setEntryWriter(entry, entryWriter);
+		};
+	}
+
+	static <T extends @Nullable Object> Function<ConfigEntry<T>, T> read(TweedDataReader reader) {
+		return read(reader, null);
+	}
+
+	static <T extends @Nullable Object> Function<ConfigEntry<T>, T> read(
 			TweedDataReader reader,
+			@Nullable Consumer<Patchwork> contextExtensionsDataCustomizer
+	) {
+		return entry -> {
+			try {
+				ReadWriteExtension extension = entry.container().extension(ReadWriteExtension.class)
+						.orElseThrow(() -> new IllegalStateException("No ReadWriteExtension present"));
+				Patchwork contextExtensionsData = extension.createReadWriteContextExtensionsData();
+				if (contextExtensionsDataCustomizer != null) {
+					contextExtensionsDataCustomizer.accept(contextExtensionsData);
+				}
+				return extension.read(reader, entry, contextExtensionsData);
+			} catch (Exception e) {
+				throw new RuntimeException(e);
+			}
+		};
+	}
+
+	static <T extends @Nullable Object> Consumer<ConfigEntry<T>> write(TweedDataVisitor writer, T value) {
+		return write(writer, value, null);
+	}
+
+	static <T extends @Nullable Object> Consumer<ConfigEntry<T>> write(
+			TweedDataVisitor writer,
+			T value,
+			@Nullable Consumer<Patchwork> contextExtensionsDataCustomizer
+	) {
+		return entry -> {
+			try {
+				ReadWriteExtension extension = entry.container().extension(ReadWriteExtension.class)
+						.orElseThrow(() -> new IllegalStateException("No ReadWriteExtension present"));
+				Patchwork contextExtensionsData = extension.createReadWriteContextExtensionsData();
+				if (contextExtensionsDataCustomizer != null) {
+					contextExtensionsDataCustomizer.accept(contextExtensionsData);
+				}
+				extension.write(writer, value, entry, contextExtensionsData);
+			} catch (Exception e) {
+				throw new RuntimeException(e);
+			}
+		};
+	}
+
+	<T, C extends ConfigEntry<T>> void setEntryReaderWriter(
 			ConfigEntry<T> entry,
-			ReadWriteContextExtensionsData contextExtensionsData
+			TweedEntryReader<T, C> entryReader,
-	) throws TweedEntryReadException;
+			TweedEntryWriter<T, C> entryWriter
+	);
+	<T, C extends ConfigEntry<T>> void setEntryReader(ConfigEntry<T> entry, TweedEntryReader<T, C> entryReader);
+	<T, C extends ConfigEntry<T>> void setEntryWriter(ConfigEntry<T> entry, TweedEntryWriter<T, C> entryWriter);
+
+	Patchwork createReadWriteContextExtensionsData();
+
+	<T extends @Nullable Object> T read(TweedDataReader reader, ConfigEntry<T> entry, Patchwork contextExtensionsData)
+			throws TweedEntryReadException;
 
 	<T extends @Nullable Object> void write(
 			TweedDataVisitor writer,
 			T value,
 			ConfigEntry<T> entry,
-			ReadWriteContextExtensionsData contextExtensionsData
+			Patchwork contextExtensionsData
 	) throws TweedEntryWriteException;
+
+	<T, C extends ConfigEntry<T>> TweedEntryReader<T, C> getReaderChain(C entry);
+	<T, C extends ConfigEntry<T>> TweedEntryWriter<T, C> getWriterChain(C entry);
 }

tweed5-serde-extension/src/main/java/de/siphalor/tweed5/data/extension/api/TweedReadContext.java

@@ -1,7 +1,8 @@
 package de.siphalor.tweed5.data.extension.api;
 
-import de.siphalor.tweed5.data.extension.api.extension.ReadWriteContextExtensionsData;
+import de.siphalor.tweed5.patchwork.api.Patchwork;
 
 public interface TweedReadContext {
-	ReadWriteContextExtensionsData extensionsData();
+	ReadWriteExtension readWriteExtension();
+	Patchwork extensionsData();
 }

tweed5-serde-extension/src/main/java/de/siphalor/tweed5/data/extension/api/TweedWriteContext.java

@@ -1,7 +1,8 @@
 package de.siphalor.tweed5.data.extension.api;
 
-import de.siphalor.tweed5.data.extension.api.extension.ReadWriteContextExtensionsData;
+import de.siphalor.tweed5.patchwork.api.Patchwork;
 
 public interface TweedWriteContext {
-	ReadWriteContextExtensionsData extensionsData();
+	ReadWriteExtension readWriteExtension();
+	Patchwork extensionsData();
 }

tweed5-serde-extension/src/main/java/de/siphalor/tweed5/data/extension/api/extension/ReadWriteContextExtensionsData.java

@@ -1,6 +0,0 @@
-package de.siphalor.tweed5.data.extension.api.extension;
-
-import de.siphalor.tweed5.patchwork.api.Patchwork;
-
-public interface ReadWriteContextExtensionsData extends Patchwork<ReadWriteContextExtensionsData> {
-}

tweed5-serde-extension/src/main/java/de/siphalor/tweed5/data/extension/api/extension/ReadWriteExtensionSetupContext.java

@@ -1,7 +1,7 @@
 package de.siphalor.tweed5.data.extension.api.extension;
 
-import de.siphalor.tweed5.core.api.extension.RegisteredExtensionData;
+import de.siphalor.tweed5.patchwork.api.PatchworkPartAccess;
 
 public interface ReadWriteExtensionSetupContext {
-	<E> RegisteredExtensionData<ReadWriteContextExtensionsData, E> registerReadWriteContextExtensionData(Class<E> extensionDataClass);
+	<E> PatchworkPartAccess<E> registerReadWriteContextExtensionData(Class<E> extensionDataClass);
 }

tweed5-serde-extension/src/main/java/de/siphalor/tweed5/data/extension/api/readwrite/TweedEntryReaderWriter.java

@@ -3,5 +3,6 @@ package de.siphalor.tweed5.data.extension.api.readwrite;
 import de.siphalor.tweed5.core.api.entry.ConfigEntry;
 import de.siphalor.tweed5.data.extension.api.TweedEntryReader;
 import de.siphalor.tweed5.data.extension.api.TweedEntryWriter;
+import org.jspecify.annotations.Nullable;
 
-public interface TweedEntryReaderWriter<T, C extends ConfigEntry<T>> extends TweedEntryReader<T, C>, TweedEntryWriter<T, C> {}
+public interface TweedEntryReaderWriter<T extends @Nullable Object, C extends ConfigEntry<T>> extends TweedEntryReader<T, C>, TweedEntryWriter<T, C> {}

tweed5-serde-extension/src/main/java/de/siphalor/tweed5/data/extension/impl/ReadWriteExtensionImpl.java

@@ -3,56 +3,41 @@ package de.siphalor.tweed5.data.extension.impl;
 import com.google.auto.service.AutoService;
 import de.siphalor.tweed5.core.api.container.ConfigContainer;
 import de.siphalor.tweed5.core.api.entry.ConfigEntry;
-import de.siphalor.tweed5.core.api.extension.EntryExtensionsData;
-import de.siphalor.tweed5.core.api.extension.RegisteredExtensionData;
 import de.siphalor.tweed5.core.api.extension.TweedExtension;
 import de.siphalor.tweed5.core.api.extension.TweedExtensionSetupContext;
 import de.siphalor.tweed5.core.api.middleware.DefaultMiddlewareContainer;
 import de.siphalor.tweed5.data.extension.api.*;
-import de.siphalor.tweed5.data.extension.api.extension.ReadWriteContextExtensionsData;
 import de.siphalor.tweed5.data.extension.api.extension.ReadWriteExtensionSetupContext;
 import de.siphalor.tweed5.data.extension.api.extension.ReadWriteRelatedExtension;
 import de.siphalor.tweed5.dataapi.api.TweedDataReadException;
 import de.siphalor.tweed5.dataapi.api.TweedDataReader;
-import de.siphalor.tweed5.dataapi.api.TweedDataWriteException;
 import de.siphalor.tweed5.dataapi.api.TweedDataVisitor;
+import de.siphalor.tweed5.dataapi.api.TweedDataWriteException;
 import de.siphalor.tweed5.patchwork.api.Patchwork;
-import de.siphalor.tweed5.patchwork.api.PatchworkClassCreator;
+import de.siphalor.tweed5.patchwork.api.PatchworkFactory;
-import de.siphalor.tweed5.patchwork.impl.PatchworkClass;
+import de.siphalor.tweed5.patchwork.api.PatchworkPartAccess;
-import de.siphalor.tweed5.patchwork.impl.PatchworkClassGenerator;
+import lombok.Data;
-import de.siphalor.tweed5.patchwork.impl.PatchworkClassPart;
-import lombok.Setter;
-import lombok.Value;
 import lombok.val;
 import org.jspecify.annotations.NonNull;
 import org.jspecify.annotations.Nullable;
 
-import java.lang.invoke.MethodHandle;
 import java.util.Collection;
-import java.util.HashMap;
-import java.util.Map;
 
 @AutoService(ReadWriteExtension.class)
 public class ReadWriteExtensionImpl implements ReadWriteExtension {
 	private final ConfigContainer<?> configContainer;
-	private final RegisteredExtensionData<EntryExtensionsData, EntryReaderWriterDefinition>
+	private final PatchworkPartAccess<CustomEntryData> customEntryDataAccess;
-			readerWriterDefinitionExtension;
-	private final RegisteredExtensionData<EntryExtensionsData, ReadWriteEntryDataExtension> readWriteEntryDataExtension;
 	private DefaultMiddlewareContainer<TweedEntryReader<?, ?>>
 			entryReaderMiddlewareContainer
 			= new DefaultMiddlewareContainer<>();
 	private DefaultMiddlewareContainer<TweedEntryWriter<?, ?>>
 			entryWriterMiddlewareContainer
 			= new DefaultMiddlewareContainer<>();
-	private final Map<Class<?>, RegisteredExtensionDataImpl<ReadWriteContextExtensionsData, ?>>
+	private @Nullable PatchworkFactory readWriteContextPatchworkFactory;
-			readWriteContextExtensionsDataClasses
-			= new HashMap<>();
-	private @Nullable PatchworkClass<@NonNull ReadWriteContextExtensionsData> readWriteContextExtensionsDataPatchwork;
 
 	public ReadWriteExtensionImpl(ConfigContainer<?> configContainer, TweedExtensionSetupContext context) {
 		this.configContainer = configContainer;
-		this.readerWriterDefinitionExtension = context.registerEntryExtensionData(EntryReaderWriterDefinition.class);
+		this.customEntryDataAccess = context.registerEntryExtensionData(CustomEntryData.class);
-		this.readWriteEntryDataExtension = context.registerEntryExtensionData(ReadWriteEntryDataExtension.class);
 	}
 
 	@Override
@@ -64,23 +49,8 @@ public class ReadWriteExtensionImpl implements ReadWriteExtension {
 	public void extensionsFinalized() {
 		Collection<TweedExtension> extensions = configContainer.extensions();
 
-		ReadWriteExtensionSetupContext setupContext = new ReadWriteExtensionSetupContext() {
+		PatchworkFactory.Builder readWriteContextPatchworkFactorBuilder = PatchworkFactory.builder();
-			@Override
+		ReadWriteExtensionSetupContext setupContext = readWriteContextPatchworkFactorBuilder::registerPart;
-			public <E> RegisteredExtensionData<ReadWriteContextExtensionsData, E> registerReadWriteContextExtensionData(
-					Class<E> extensionDataClass
-			) {
-				if (readWriteContextExtensionsDataClasses.containsKey(extensionDataClass)) {
-					throw new IllegalArgumentException("Context extension "
-							+ extensionDataClass.getName()
-							+ " is already registered");
-				}
-				RegisteredExtensionDataImpl<ReadWriteContextExtensionsData, E>
-						registeredExtensionData
-						= new RegisteredExtensionDataImpl<>();
-				readWriteContextExtensionsDataClasses.put(extensionDataClass, registeredExtensionData);
-				return registeredExtensionData;
-			}
-		};
 
 		entryReaderMiddlewareContainer = new DefaultMiddlewareContainer<>();
 		entryWriterMiddlewareContainer = new DefaultMiddlewareContainer<>();
@@ -102,79 +72,62 @@ public class ReadWriteExtensionImpl implements ReadWriteExtension {
 			}
 		}
 
+		readWriteContextPatchworkFactory = readWriteContextPatchworkFactorBuilder.build();
+
 		entryReaderMiddlewareContainer.seal();
 		entryWriterMiddlewareContainer.seal();
+	}
 
-		val patchworkClassCreator = PatchworkClassCreator.<ReadWriteContextExtensionsData>builder()
+	@Override
-				.patchworkInterface(ReadWriteContextExtensionsData.class)
+	public <T, C extends ConfigEntry<T>> void setEntryReaderWriter(
-				.classPackage("de.siphalor.tweed5.data.extension.generated")
+			ConfigEntry<T> entry,
-				.classPrefix("ReadWriteContextExtensionsData$")
+			TweedEntryReader<T, C> entryReader,
-				.build();
+			TweedEntryWriter<T, C> entryWriter
+	) {
+		CustomEntryData customEntryData = getOrCreateCustomEntryData(entry);
+		customEntryData.readerDefinition(entryReader);
+		customEntryData.writerDefinition(entryWriter);
+	}
 
-		try {
+	@Override
-			readWriteContextExtensionsDataPatchwork =
+	public <T, C extends ConfigEntry<T>> void setEntryReader(ConfigEntry<T> entry, TweedEntryReader<T, C> entryReader) {
-					patchworkClassCreator.createClass(readWriteContextExtensionsDataClasses.keySet());
+		getOrCreateCustomEntryData(entry).readerDefinition(entryReader);
-			for (PatchworkClassPart patchworkClassPart : readWriteContextExtensionsDataPatchwork.parts()) {
+	}
-				RegisteredExtensionDataImpl<ReadWriteContextExtensionsData, ?>
+
-						registeredExtension
+	@Override
-						= readWriteContextExtensionsDataClasses.get(patchworkClassPart.partInterface());
+	public <T, C extends ConfigEntry<T>> void setEntryWriter(ConfigEntry<T> entry, TweedEntryWriter<T, C> entryWriter) {
-				registeredExtension.setter = patchworkClassPart.fieldSetter();
+		getOrCreateCustomEntryData(entry).writerDefinition(entryWriter);
-			}
-		} catch (PatchworkClassGenerator.GenerationException e) {
-			throw new IllegalStateException(
-					"Failed to generate read write context extensions' data patchwork class",
-					e
-			);
-		}
 	}
 
 	@Override
 	public void initEntry(ConfigEntry<?> configEntry) {
-		TweedEntryReader<?, ?> baseReader;
+		CustomEntryData customEntryData = getOrCreateCustomEntryData(configEntry);
-		TweedEntryWriter<?, ?> baseWriter;
+		customEntryData.readerChain(entryReaderMiddlewareContainer.process(customEntryData.readerDefinition()));
-		if (configEntry.extensionsData().isPatchworkPartSet(EntryReaderWriterDefinition.class)) {
+		customEntryData.writerChain(entryWriterMiddlewareContainer.process(customEntryData.writerDefinition()));
-			EntryReaderWriterDefinition rwDefintion = (EntryReaderWriterDefinition) configEntry.extensionsData();
+	}
-			baseReader = rwDefintion.reader();
+
-			baseWriter = rwDefintion.writer();
+	private CustomEntryData getOrCreateCustomEntryData(ConfigEntry<?> entry) {
-		} else {
+		CustomEntryData entryData = entry.extensionsData().get(customEntryDataAccess);
-			baseReader = TweedEntryReaderWriterImpls.NOOP_READER_WRITER;
+		if (entryData == null) {
-			baseWriter = TweedEntryReaderWriterImpls.NOOP_READER_WRITER;
+			entryData = new CustomEntryData();
+			entry.extensionsData().set(customEntryDataAccess, entryData);
 		}
-
+		return entryData;
-		readWriteEntryDataExtension.set(
-				configEntry.extensionsData(), new ReadWriteEntryDataExtensionImpl(
-						entryReaderMiddlewareContainer.process(baseReader),
-						entryWriterMiddlewareContainer.process(baseWriter)
-				)
-		);
 	}
 
 	@Override
-	public void setEntryReaderWriterDefinition(
+	public Patchwork createReadWriteContextExtensionsData() {
-			@NonNull ConfigEntry<?> entry,
+		assert readWriteContextPatchworkFactory != null;
-			@NonNull EntryReaderWriterDefinition readerWriterDefinition
+		return readWriteContextPatchworkFactory.create();
-	) {
-		readerWriterDefinitionExtension.set(entry.extensionsData(), readerWriterDefinition);
 	}
 
-	@Override
-	public ReadWriteContextExtensionsData createReadWriteContextExtensionsData() {
-		try {
-			assert readWriteContextExtensionsDataPatchwork != null;
-			return (ReadWriteContextExtensionsData) readWriteContextExtensionsDataPatchwork.constructor().invoke();
-		} catch (Throwable e) {
-			throw new IllegalStateException("Failed to instantiate read write context extensions' data", e);
-		}
-	}
-
-	@Override
 	public <T extends @Nullable Object> T read(
-			@NonNull TweedDataReader reader,
+			TweedDataReader reader,
-			@NonNull ConfigEntry<T> entry,
+			ConfigEntry<T> entry,
-			@NonNull ReadWriteContextExtensionsData contextExtensionsData
+			Patchwork contextExtensionsData
 	) throws TweedEntryReadException {
 		try {
-			return getReaderChain(entry).read(reader, entry, new TweedReadWriteContextImpl(contextExtensionsData));
+			return getReaderChain(entry).read(reader, entry, new TweedReadWriteContextImpl(this, contextExtensionsData));
 		} catch (TweedDataReadException e) {
 			throw new TweedEntryReadException("Failed to read entry", e);
 		}
@@ -182,46 +135,35 @@ public class ReadWriteExtensionImpl implements ReadWriteExtension {
 
 	@Override
 	public <T extends @Nullable Object> void write(
-			@NonNull TweedDataVisitor writer,
+			TweedDataVisitor writer,
 			@Nullable T value,
-			@NonNull ConfigEntry<T> entry,
+			ConfigEntry<T> entry,
-			@NonNull ReadWriteContextExtensionsData contextExtensionsData
+			Patchwork contextExtensionsData
 	) throws TweedEntryWriteException {
 		try {
-			getWriterChain(entry).write(writer, value, entry, new TweedReadWriteContextImpl(contextExtensionsData));
+			getWriterChain(entry).write(writer, value, entry, new TweedReadWriteContextImpl(this, contextExtensionsData));
 		} catch (TweedDataWriteException e) {
 			throw new TweedEntryWriteException("Failed to write entry", e);
 		}
 	}
 
-	@Value
+	@Data
-	private static class ReadWriteEntryDataExtensionImpl implements ReadWriteEntryDataExtension {
+	private static class CustomEntryData {
-		TweedEntryReader<?, ?> entryReaderChain;
+		private TweedEntryReader<?, ?> readerDefinition = TweedEntryReaderWriterImpls.NOOP_READER_WRITER;
-		TweedEntryWriter<?, ?> entryWriterChain;
+		private TweedEntryWriter<?, ?> writerDefinition = TweedEntryReaderWriterImpls.NOOP_READER_WRITER;
+		private TweedEntryReader<?, ?> readerChain;
+		private TweedEntryWriter<?, ?> writerChain;
 	}
 
-	@Setter
+	@Override
-	private static class RegisteredExtensionDataImpl<U extends Patchwork<@NonNull U>, E>
+	public <T, C extends ConfigEntry<T>> TweedEntryReader<T, C> getReaderChain(C entry) {
-			implements RegisteredExtensionData<U, E> {
-		private MethodHandle setter;
-
-		@Override
-		public void set(U patchwork, E extension) {
-			try {
-				setter.invokeWithArguments(patchwork, extension);
-			} catch (Throwable e) {
-				throw new IllegalStateException(e);
-			}
-		}
-	}
-
-	static <T> TweedEntryReader<T, @NonNull ConfigEntry<T>> getReaderChain(ConfigEntry<T> elementEntry) {
 		//noinspection unchecked
-		return (TweedEntryReader<T, @NonNull ConfigEntry<T>>) ((ReadWriteEntryDataExtension) elementEntry.extensionsData()).entryReaderChain();
+		return (TweedEntryReader<T, C>) entry.extensionsData().get(customEntryDataAccess).readerChain();
 	}
 
-	static <T> TweedEntryWriter<T, @NonNull ConfigEntry<T>> getWriterChain(ConfigEntry<T> elementEntry) {
+	@Override
+	public <T, C extends ConfigEntry<T>> TweedEntryWriter<T, C> getWriterChain(C entry) {
 		//noinspection unchecked
-		return (TweedEntryWriter<T, @NonNull ConfigEntry<T>>) ((ReadWriteEntryDataExtension) elementEntry.extensionsData()).entryWriterChain();
+		return (TweedEntryWriter<T, C>) entry.extensionsData().get(customEntryDataAccess).writerChain();
 	}
 }

tweed5-serde-extension/src/main/java/de/siphalor/tweed5/data/extension/impl/TweedEntryReaderWriterImpls.java

@@ -10,7 +10,6 @@ import lombok.AccessLevel;
 import lombok.NoArgsConstructor;
 import lombok.RequiredArgsConstructor;
 import org.jetbrains.annotations.Contract;
-import org.jspecify.annotations.NonNull;
 import org.jspecify.annotations.Nullable;
 
 import java.util.*;
@@ -63,7 +62,7 @@ public class TweedEntryReaderWriterImpls {
 	}
 
 	@RequiredArgsConstructor
-	private static class PrimitiveReaderWriter<T extends @NonNull Object> implements TweedEntryReaderWriter<T, ConfigEntry<T>> {
+	private static class PrimitiveReaderWriter<T extends @Nullable Object> implements TweedEntryReaderWriter<T, ConfigEntry<T>> {
 		private final Function<TweedDataToken, T> readerCall;
 		private final BiConsumer<TweedDataVisitor, T> writerCall;
 
@@ -79,7 +78,7 @@ public class TweedEntryReaderWriterImpls {
 		}
 	}
 
-	public static class CollectionReaderWriter<T extends @NonNull Object, C extends Collection<T>> implements TweedEntryReaderWriter<C, CollectionConfigEntry<T, C>> {
+	public static class CollectionReaderWriter<T extends @Nullable Object, C extends Collection<T>> implements TweedEntryReaderWriter<C, CollectionConfigEntry<T, C>> {
 		@Override
 		public C read(TweedDataReader reader, CollectionConfigEntry<T, C> entry, TweedReadContext context) throws TweedEntryReadException, TweedDataReadException {
 			assertIsToken(reader.readToken(), TweedDataToken::isListStart, "Expected list start");
@@ -89,9 +88,9 @@ public class TweedEntryReaderWriterImpls {
 			}
 
 			ConfigEntry<T> elementEntry = entry.elementEntry();
-			TweedEntryReader<T, ConfigEntry<T>> elementReader = ReadWriteExtensionImpl.getReaderChain(elementEntry);
+			TweedEntryReader<T, ConfigEntry<T>> elementReader = context.readWriteExtension().getReaderChain(elementEntry);
 
-			List<T> list = new ArrayList<>(20);
+			List<@Nullable T> list = new ArrayList<>(20);
 			while (true) {
 				token = reader.peekToken();
 				if (token.isListEnd()) {
@@ -119,7 +118,7 @@ public class TweedEntryReaderWriterImpls {
 			}
 
 			ConfigEntry<T> elementEntry = entry.elementEntry();
-			TweedEntryWriter<T, ConfigEntry<T>> elementWriter = ReadWriteExtensionImpl.getWriterChain(elementEntry);
+			TweedEntryWriter<T, ConfigEntry<T>> elementWriter = context.readWriteExtension().getWriterChain(elementEntry);
 
 			writer.visitListStart();
 			for (T element : value) {
@@ -129,7 +128,7 @@ public class TweedEntryReaderWriterImpls {
 		}
 	}
 
-	public static class CompoundReaderWriter<T extends @NonNull Object> implements TweedEntryReaderWriter<T, CompoundConfigEntry<T>> {
+	public static class CompoundReaderWriter<T> implements TweedEntryReaderWriter<T, CompoundConfigEntry<T>> {
 		@Override
 		public T read(TweedDataReader reader, CompoundConfigEntry<T> entry, TweedReadContext context) throws TweedEntryReadException, TweedDataReadException {
 			assertIsToken(reader.readToken(), TweedDataToken::isMapStart, "Expected map start");
@@ -145,7 +144,7 @@ public class TweedEntryReaderWriterImpls {
 
 					//noinspection unchecked
 					ConfigEntry<Object> subEntry = (ConfigEntry<Object>) compoundEntries.get(key);
-					TweedEntryReader<Object, ConfigEntry<Object>> subEntryReaderChain = ReadWriteExtensionImpl.getReaderChain(subEntry);
+					TweedEntryReader<Object, ConfigEntry<Object>> subEntryReaderChain = context.readWriteExtension().getReaderChain(subEntry);
 					Object subEntryValue = subEntryReaderChain.read(reader, subEntry, context);
 					entry.set(compoundValue, key, subEntryValue);
 				} else {
@@ -167,7 +166,7 @@ public class TweedEntryReaderWriterImpls {
 				String key = e.getKey();
 				ConfigEntry<Object> subEntry = e.getValue();
 
-				TweedEntryWriter<Object, ConfigEntry<Object>> subEntryWriterChain = ReadWriteExtensionImpl.getWriterChain(subEntry);
+				TweedEntryWriter<Object, ConfigEntry<Object>> subEntryWriterChain = context.readWriteExtension().getWriterChain(subEntry);
 
 				writer.visitMapEntryKey(key);
 				subEntryWriterChain.write(writer, entry.get(value, key), subEntry, context);

tweed5-serde-extension/src/main/java/de/siphalor/tweed5/data/extension/impl/TweedReadWriteContextImpl.java

@@ -1,11 +1,13 @@
 package de.siphalor.tweed5.data.extension.impl;
 
+import de.siphalor.tweed5.data.extension.api.ReadWriteExtension;
 import de.siphalor.tweed5.data.extension.api.TweedReadContext;
 import de.siphalor.tweed5.data.extension.api.TweedWriteContext;
-import de.siphalor.tweed5.data.extension.api.extension.ReadWriteContextExtensionsData;
+import de.siphalor.tweed5.patchwork.api.Patchwork;
 import lombok.Value;
 
 @Value
 public class TweedReadWriteContextImpl implements TweedReadContext, TweedWriteContext {
-	ReadWriteContextExtensionsData extensionsData;
+	ReadWriteExtension readWriteExtension;
+	Patchwork extensionsData;
 }

tweed5-serde-extension/src/test/java/de/siphalor/tweed5/data/extension/impl/ReadWriteExtensionImplTest.java

@@ -1,23 +1,18 @@
 package de.siphalor.tweed5.data.extension.impl;
 
 import de.siphalor.tweed5.core.api.container.ConfigContainer;
-import de.siphalor.tweed5.core.api.extension.EntryExtensionsData;
+import de.siphalor.tweed5.core.api.entry.CollectionConfigEntry;
-import de.siphalor.tweed5.core.api.extension.RegisteredExtensionData;
+import de.siphalor.tweed5.core.api.entry.CompoundConfigEntry;
+import de.siphalor.tweed5.core.api.entry.SimpleConfigEntry;
 import de.siphalor.tweed5.core.impl.DefaultConfigContainer;
 import de.siphalor.tweed5.core.impl.entry.CollectionConfigEntryImpl;
 import de.siphalor.tweed5.core.impl.entry.SimpleConfigEntryImpl;
 import de.siphalor.tweed5.core.impl.entry.StaticMapCompoundConfigEntryImpl;
-import de.siphalor.tweed5.data.extension.api.EntryReaderWriterDefinition;
 import de.siphalor.tweed5.data.extension.api.ReadWriteExtension;
-import de.siphalor.tweed5.data.extension.api.TweedEntryReader;
-import de.siphalor.tweed5.data.extension.api.TweedEntryWriter;
-import de.siphalor.tweed5.data.extension.api.readwrite.TweedEntryReaderWriter;
-import de.siphalor.tweed5.data.extension.api.readwrite.TweedEntryReaderWriters;
 import de.siphalor.tweed5.data.hjson.HjsonLexer;
 import de.siphalor.tweed5.data.hjson.HjsonReader;
 import de.siphalor.tweed5.data.hjson.HjsonWriter;
 import de.siphalor.tweed5.dataapi.api.TweedDataVisitor;
-import lombok.RequiredArgsConstructor;
 import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.Test;
 
@@ -27,6 +22,8 @@ import java.io.Writer;
 import java.util.*;
 import java.util.function.Function;
 
+import static de.siphalor.tweed5.data.extension.api.ReadWriteExtension.entryReaderWriter;
+import static de.siphalor.tweed5.data.extension.api.readwrite.TweedEntryReaderWriters.*;
 import static de.siphalor.tweed5.testutils.MapTestUtils.sequencedMap;
 import static java.util.Map.entry;
 import static org.assertj.core.api.Assertions.assertThat;
@@ -36,7 +33,7 @@ import static org.junit.jupiter.api.Assertions.assertEquals;
 class ReadWriteExtensionImplTest {
 	private final StringWriter stringWriter = new StringWriter();
 	private final ConfigContainer<Map<String, Object>> configContainer = new DefaultConfigContainer<>();
-	private StaticMapCompoundConfigEntryImpl<Map<String, Object>> rootEntry;
+	private CompoundConfigEntry<Map<String, Object>> rootEntry;
 
 	@SuppressWarnings("unchecked")
 	@BeforeEach
@@ -44,14 +41,16 @@ class ReadWriteExtensionImplTest {
 		configContainer.registerExtension(ReadWriteExtension.DEFAULT);
 		configContainer.finishExtensionSetup();
 
-		SimpleConfigEntryImpl<Integer> intEntry = new SimpleConfigEntryImpl<>(configContainer, Integer.class);
+		SimpleConfigEntry<Integer> intEntry = new SimpleConfigEntryImpl<>(configContainer, Integer.class)
-		SimpleConfigEntryImpl<Boolean> booleanEntry = new SimpleConfigEntryImpl<>(configContainer, Boolean.class);
+				.apply(entryReaderWriter(intReaderWriter()));
-		CollectionConfigEntryImpl<Boolean, List<Boolean>> listEntry = new CollectionConfigEntryImpl<>(
+
+		CollectionConfigEntry<Boolean, List<Boolean>> listEntry = new CollectionConfigEntryImpl<>(
 				configContainer,
 				(Class<List<Boolean>>) (Class<?>) List.class,
 				ArrayList::new,
-				booleanEntry
+				new SimpleConfigEntryImpl<>(configContainer, Boolean.class)
-		);
+						.apply(entryReaderWriter(booleanReaderWriter()))
+		).apply(entryReaderWriter(collectionReaderWriter()));
 
 		rootEntry = new StaticMapCompoundConfigEntryImpl<>(
 				configContainer,
@@ -61,16 +60,9 @@ class ReadWriteExtensionImplTest {
 						entry("int", intEntry),
 						entry("list", listEntry)
 				))
-		);
+		).apply(entryReaderWriter(compoundReaderWriter()));
 
 		configContainer.attachTree(rootEntry);
-
-		RegisteredExtensionData<EntryExtensionsData, EntryReaderWriterDefinition> readerWriterData = (RegisteredExtensionData<EntryExtensionsData, EntryReaderWriterDefinition>) configContainer.entryDataExtensions().get(EntryReaderWriterDefinition.class);
-		readerWriterData.set(rootEntry.extensionsData(), new TrivialEntryReaderWriterDefinition(TweedEntryReaderWriters.compoundReaderWriter()));
-		readerWriterData.set(intEntry.extensionsData(), new TrivialEntryReaderWriterDefinition(TweedEntryReaderWriters.intReaderWriter()));
-		readerWriterData.set(listEntry.extensionsData(), new TrivialEntryReaderWriterDefinition(TweedEntryReaderWriters.collectionReaderWriter()));
-		readerWriterData.set(booleanEntry.extensionsData(), new TrivialEntryReaderWriterDefinition(TweedEntryReaderWriters.booleanReaderWriter()));
-
 		configContainer.initialize();
 	}
 
@@ -128,19 +120,4 @@ class ReadWriteExtensionImplTest {
 	private TweedDataVisitor setupWriter(Function<Writer, TweedDataVisitor> writerFactory) {
 		return writerFactory.apply(stringWriter);
 	}
-
-	@RequiredArgsConstructor
-	private static class TrivialEntryReaderWriterDefinition implements EntryReaderWriterDefinition {
-		private final TweedEntryReaderWriter<?, ?> readerWriter;
-
-		@Override
-		public TweedEntryReader<?, ?> reader() {
-			return readerWriter;
-		}
-
-		@Override
-		public TweedEntryWriter<?, ?> writer() {
-			return readerWriter;
-		}
-	}
 }

tweed5-weaver-pojo-serde-extension/src/main/java/de/siphalor/tweed5/weaver/pojoext/serde/api/ReadWritePojoPostProcessor.java

@@ -74,49 +74,32 @@ public class ReadWritePojoPostProcessor implements TweedPojoWeavingPostProcessor
 			return;
 		}
 
-		EntryReaderWriterDefinition definition = createDefinitionFromEntryConfig(entryConfig, context);
+		//noinspection rawtypes,unchecked
-		if (definition != null) {
+		readWriteExtension.setEntryReaderWriter(
-			readWriteExtension.setEntryReaderWriterDefinition(configEntry, definition);
+				(ConfigEntry) configEntry,
-		}
+				(TweedEntryReader) resolveReader(entryConfig, context),
+				(TweedEntryWriter) resolveWriter(entryConfig, context)
+		);
 	}
 
-	private @Nullable EntryReaderWriterDefinition createDefinitionFromEntryConfig(EntryReadWriteConfig entryConfig, WeavingContext context) {
+	private TweedEntryReader<?, ?> resolveReader(EntryReadWriteConfig entryConfig, WeavingContext context) {
-		String readerSpecText = entryConfig.reader().isEmpty() ? entryConfig.value() : entryConfig.reader();
+		String specText = entryConfig.reader().isEmpty() ? entryConfig.value() : entryConfig.reader();
-		String writerSpecText = entryConfig.writer().isEmpty() ? entryConfig.value() : entryConfig.writer();
+		SerdePojoReaderWriterSpec spec = specFromText(specText, context);
-
-		SerdePojoReaderWriterSpec readerSpec;
-		SerdePojoReaderWriterSpec writerSpec;
-		if (readerSpecText.equals(writerSpecText)) {
-			readerSpec = writerSpec = specFromText(readerSpecText, context);
-		} else {
-			readerSpec = specFromText(readerSpecText, context);
-			writerSpec = specFromText(writerSpecText, context);
-		}
-
-		if (readerSpec == null && writerSpec == null) {
-			return null;
-		}
 
 		//noinspection unchecked,rawtypes
-		TweedEntryReader<?, ?> reader = Optional.ofNullable(readerSpec)
+		return Optional.ofNullable(spec)
-				.map((spec) -> resolveReaderWriterFromSpec((Class<TweedEntryReader<?, ?>>)(Object) TweedEntryReader.class, readerFactories, spec, context))
+				.map(s -> resolveReaderWriterFromSpec((Class<TweedEntryReader<?, ?>>)(Object) TweedEntryReader.class, readerFactories, s, context))
 				.orElse(((TweedEntryReader) TweedEntryReaderWriterImpls.NOOP_READER_WRITER));
+	}
+
+	private TweedEntryWriter<?, ?> resolveWriter(EntryReadWriteConfig entryConfig, WeavingContext context) {
+		String specText = entryConfig.writer().isEmpty() ? entryConfig.value() : entryConfig.writer();
+		SerdePojoReaderWriterSpec spec = specFromText(specText, context);
+
 		//noinspection unchecked,rawtypes
-		TweedEntryWriter<?, ?> writer = Optional.ofNullable(writerSpec)
+		return Optional.ofNullable(spec)
-				.map((spec) -> resolveReaderWriterFromSpec((Class<TweedEntryWriter<?, ?>>)(Object) TweedEntryWriter.class, writerFactories, spec, context))
+				.map(s -> resolveReaderWriterFromSpec((Class<TweedEntryWriter<?, ?>>)(Object) TweedEntryWriter.class, writerFactories, s, context))
 				.orElse(((TweedEntryWriter) TweedEntryReaderWriterImpls.NOOP_READER_WRITER));
-
-		return new EntryReaderWriterDefinition() {
-			@Override
-			public TweedEntryReader<?, ?> reader() {
-				return reader;
-			}
-
-			@Override
-			public TweedEntryWriter<?, ?> writer() {
-				return writer;
-			}
-		};
 	}
 
 	private @Nullable SerdePojoReaderWriterSpec specFromText(String specText, WeavingContext context) {

tweed5-weaver-pojo/src/main/java/de/siphalor/tweed5/weaver/pojo/api/weaving/CollectionPojoWeaver.java

@@ -2,7 +2,8 @@ package de.siphalor.tweed5.weaver.pojo.api.weaving;
 
 import de.siphalor.tweed5.core.api.container.ConfigContainer;
 import de.siphalor.tweed5.core.api.entry.ConfigEntry;
-import de.siphalor.tweed5.core.api.extension.RegisteredExtensionData;
+import de.siphalor.tweed5.patchwork.api.Patchwork;
+import de.siphalor.tweed5.patchwork.api.PatchworkPartAccess;
 import de.siphalor.tweed5.typeutils.api.type.ActualType;
 import de.siphalor.tweed5.weaver.pojo.api.annotation.CollectionWeaving;
 import de.siphalor.tweed5.weaver.pojo.api.entry.WeavableCollectionConfigEntry;
@@ -24,24 +25,27 @@ public class CollectionPojoWeaver implements TweedPojoWeaver {
 			.collectionEntryClass(CollectionConfigEntryImpl.class)
 			.build();
 
-	private RegisteredExtensionData<WeavingContext.ExtensionsData, CollectionWeavingConfig> weavingConfigAccess;
+	@Nullable
+	private PatchworkPartAccess<CollectionWeavingConfig> weavingConfigAccess;
 
 	@Override
 	public void setup(SetupContext context) {
 		this.weavingConfigAccess = context.registerWeavingContextExtensionData(CollectionWeavingConfig.class);
 	}
 
-	@SuppressWarnings({"rawtypes", "unchecked"})
+	@SuppressWarnings({"unchecked"})
 	@Override
 	public <T> @Nullable ConfigEntry<T> weaveEntry(ActualType<T> valueType, WeavingContext context) {
+		assert weavingConfigAccess != null;
+
 		List<ActualType<?>> collectionTypeParams = valueType.getTypesOfSuperArguments(Collection.class);
 		if (collectionTypeParams == null) {
 			return null;
 		}
 		try {
 			CollectionWeavingConfig weavingConfig = getOrCreateWeavingConfig(context);
-			WeavingContext.ExtensionsData newExtensionsData = context.extensionsData().copy();
+			Patchwork newExtensionsData = context.extensionsData().copy();
-			weavingConfigAccess.set(newExtensionsData, weavingConfig);
+			newExtensionsData.set(weavingConfigAccess, weavingConfig);
 
 			IntFunction<Collection<Object>> constructor = getCollectionConstructor(valueType);
 
@@ -66,10 +70,10 @@ public class CollectionPojoWeaver implements TweedPojoWeaver {
 	}
 
 	private CollectionWeavingConfig getOrCreateWeavingConfig(WeavingContext context) {
-		CollectionWeavingConfig parent;
+		assert weavingConfigAccess != null;
-		if (context.extensionsData().isPatchworkPartSet(CollectionWeavingConfig.class)) {
+
-			parent = (CollectionWeavingConfig) context.extensionsData();
+		CollectionWeavingConfig parent = context.extensionsData().get(weavingConfigAccess);
-		} else {
+		if (parent == null) {
 			parent = DEFAULT_WEAVING_CONFIG;
 		}
 

tweed5-weaver-pojo/src/main/java/de/siphalor/tweed5/weaver/pojo/api/weaving/CompoundPojoWeaver.java

@@ -2,10 +2,11 @@ package de.siphalor.tweed5.weaver.pojo.api.weaving;
 
 import de.siphalor.tweed5.core.api.container.ConfigContainer;
 import de.siphalor.tweed5.core.api.entry.ConfigEntry;
-import de.siphalor.tweed5.core.api.extension.RegisteredExtensionData;
 import de.siphalor.tweed5.namingformat.api.NamingFormat;
 import de.siphalor.tweed5.namingformat.api.NamingFormatCollector;
 import de.siphalor.tweed5.namingformat.api.NamingFormats;
+import de.siphalor.tweed5.patchwork.api.Patchwork;
+import de.siphalor.tweed5.patchwork.api.PatchworkPartAccess;
 import de.siphalor.tweed5.weaver.pojo.api.annotation.CompoundWeaving;
 import de.siphalor.tweed5.weaver.pojo.api.entry.WeavableCompoundConfigEntry;
 import de.siphalor.tweed5.typeutils.api.type.ActualType;
@@ -22,7 +23,6 @@ import java.lang.invoke.MethodHandle;
 import java.lang.reflect.AnnotatedElement;
 import java.lang.reflect.Field;
 import java.util.List;
-import java.util.Map;
 import java.util.function.Supplier;
 import java.util.stream.Collectors;
 
@@ -37,7 +37,8 @@ public class CompoundPojoWeaver implements TweedPojoWeaver {
 			.build();
 
 	private final NamingFormatCollector namingFormatCollector = new NamingFormatCollector();
-	private RegisteredExtensionData<WeavingContext.ExtensionsData, CompoundWeavingConfig> weavingConfigAccess;
+	@Nullable
+	private PatchworkPartAccess<CompoundWeavingConfig> weavingConfigAccess;
 
 	public void setup(SetupContext context) {
 		namingFormatCollector.setupFormats();
@@ -47,13 +48,15 @@ public class CompoundPojoWeaver implements TweedPojoWeaver {
 
 	@Override
 	public <T> @Nullable ConfigEntry<T> weaveEntry(ActualType<T> valueType, WeavingContext context) {
+		assert weavingConfigAccess != null;
+
 		if (context.annotations().getAnnotation(CompoundWeaving.class) == null) {
 			return null;
 		}
 		try {
 			CompoundWeavingConfig weavingConfig = getOrCreateWeavingConfig(context);
-			WeavingContext.ExtensionsData newExtensionsData = context.extensionsData().copy();
+			Patchwork newExtensionsData = context.extensionsData().copy();
-			weavingConfigAccess.set(newExtensionsData, weavingConfig);
+			newExtensionsData.set(weavingConfigAccess, weavingConfig);
 
 			PojoClassIntrospector introspector = PojoClassIntrospector.forClass(valueType.declaredType());
 
@@ -69,10 +72,10 @@ public class CompoundPojoWeaver implements TweedPojoWeaver {
 	}
 
 	private CompoundWeavingConfig getOrCreateWeavingConfig(WeavingContext context) {
-		CompoundWeavingConfig parent;
+		assert weavingConfigAccess != null;
-		if (context.extensionsData().isPatchworkPartSet(CompoundWeavingConfig.class)) {
+
-			parent = (CompoundWeavingConfig) context.extensionsData();
+		CompoundWeavingConfig parent = context.extensionsData().get(weavingConfigAccess);
-		} else {
+		if (parent == null) {
 			parent = DEFAULT_WEAVING_CONFIG;
 		}
 
@@ -143,10 +146,14 @@ public class CompoundPojoWeaver implements TweedPojoWeaver {
 
 	private WeavableCompoundConfigEntry.SubEntry weaveCompoundSubEntry(
 			PojoClassIntrospector.Property property,
-			WeavingContext.ExtensionsData newExtensionsData,
+			Patchwork newExtensionsData,
 			WeavingContext parentContext
 	) {
-		String name = convertName(property.field().getName(), (CompoundWeavingConfig) newExtensionsData);
+		assert weavingConfigAccess != null;
+		CompoundWeavingConfig weavingConfig = newExtensionsData.get(weavingConfigAccess);
+		assert weavingConfig != null;
+
+		String name = convertName(property.field().getName(), weavingConfig);
 		WeavingContext subContext = createSubContextForProperty(property, name, newExtensionsData, parentContext);
 
 		ConfigEntry<?> subEntry;
@@ -189,7 +196,7 @@ public class CompoundPojoWeaver implements TweedPojoWeaver {
 	private WeavingContext createSubContextForProperty(
 			PojoClassIntrospector.Property property,
 			String name,
-			WeavingContext.ExtensionsData newExtensionsData,
+			Patchwork newExtensionsData,
 			WeavingContext parentContext
 	) {
 		return parentContext.subContextBuilder(name)

tweed5-weaver-pojo/src/main/java/de/siphalor/tweed5/weaver/pojo/api/weaving/TweedPojoWeaver.java

@@ -1,7 +1,8 @@
 package de.siphalor.tweed5.weaver.pojo.api.weaving;
 
 import de.siphalor.tweed5.construct.api.TweedConstructFactory;
-import de.siphalor.tweed5.core.api.extension.RegisteredExtensionData;
+import de.siphalor.tweed5.patchwork.api.PatchworkFactory;
+import de.siphalor.tweed5.patchwork.api.PatchworkPartAccess;
 import org.jetbrains.annotations.ApiStatus;
 
 public interface TweedPojoWeaver extends TweedPojoWeavingFunction {
@@ -11,6 +12,6 @@ public interface TweedPojoWeaver extends TweedPojoWeavingFunction {
 	void setup(SetupContext context);
 
 	interface SetupContext {
-		<E> RegisteredExtensionData<WeavingContext.ExtensionsData, E> registerWeavingContextExtensionData(Class<E> dataClass);
+		<E> PatchworkPartAccess<E> registerWeavingContextExtensionData(Class<E> dataClass);
 	}
 }

tweed5-weaver-pojo/src/main/java/de/siphalor/tweed5/weaver/pojo/api/weaving/WeavingContext.java

@@ -18,7 +18,7 @@ public class WeavingContext implements TweedPojoWeavingFunction.NonNull {
 	TweedPojoWeavingFunction.NonNull weavingFunction;
 	ConfigContainer<?> configContainer;
 	String[] path;
-	ExtensionsData extensionsData;
+	Patchwork extensionsData;
 	AnnotatedElement annotations;
 
 	public static Builder builder(TweedPojoWeavingFunction.NonNull weavingFunction, ConfigContainer<?> configContainer) {
@@ -40,8 +40,6 @@ public class WeavingContext implements TweedPojoWeavingFunction.NonNull {
 		return weavingFunction.weaveEntry(valueType, context);
 	}
 
-	public interface ExtensionsData extends Patchwork<ExtensionsData> {}
-
 	@Accessors(fluent = true, chain = true)
 	@Setter
 	@RequiredArgsConstructor(access = AccessLevel.PRIVATE)
@@ -51,7 +49,7 @@ public class WeavingContext implements TweedPojoWeavingFunction.NonNull {
 		private final TweedPojoWeavingFunction.NonNull weavingFunction;
 		private final ConfigContainer<?> configContainer;
 		private final String[] path;
-		private ExtensionsData extensionsData;
+		private Patchwork extensionsData;
 		private AnnotatedElement annotations;
 
 		public WeavingContext build() {

tweed5-weaver-pojo/src/main/java/de/siphalor/tweed5/weaver/pojo/impl/entry/CollectionConfigEntryImpl.java

@@ -62,7 +62,7 @@ public class CollectionConfigEntryImpl<E, T extends Collection<E>> extends BaseC
 	}
 
 	@Override
-	public @NotNull T deepCopy(@NotNull T value) {
+	public @NotNull T deepCopy(T value) {
 		T copy = instantiateCollection(value.size());
 		for (E element : value) {
 			copy.add(elementEntry.deepCopy(element));

tweed5-weaver-pojo/src/main/java/de/siphalor/tweed5/weaver/pojo/impl/entry/StaticPojoCompoundConfigEntry.java

@@ -7,6 +7,7 @@ import de.siphalor.tweed5.core.api.entry.ConfigEntry;
 import de.siphalor.tweed5.core.api.entry.ConfigEntryValueVisitor;
 import de.siphalor.tweed5.core.api.entry.ConfigEntryVisitor;
 import de.siphalor.tweed5.weaver.pojo.api.entry.WeavableCompoundConfigEntry;
+import org.jspecify.annotations.Nullable;
 
 import java.util.Collections;
 import java.util.LinkedHashMap;
@@ -97,7 +98,7 @@ public class StaticPojoCompoundConfigEntry<T> extends BaseConfigEntry<T> impleme
 	}
 
 	@Override
-	public void visitInOrder(ConfigEntryValueVisitor visitor, T value) {
+	public void visitInOrder(ConfigEntryValueVisitor visitor, @Nullable T value) {
 		if (visitor.enterCompoundEntry(this, value)) {
 			subEntries.forEach((key, entry) -> {
 				if (visitor.enterCompoundSubEntry(key)) {

tweed5-weaver-pojo/src/main/java/de/siphalor/tweed5/weaver/pojo/impl/weaving/TweedPojoWeaverBootstrapper.java

@@ -2,22 +2,21 @@ package de.siphalor.tweed5.weaver.pojo.impl.weaving;
 
 import de.siphalor.tweed5.core.api.container.ConfigContainer;
 import de.siphalor.tweed5.core.api.entry.ConfigEntry;
-import de.siphalor.tweed5.core.api.extension.RegisteredExtensionData;
+import de.siphalor.tweed5.patchwork.api.Patchwork;
-import de.siphalor.tweed5.patchwork.api.PatchworkClassCreator;
+import de.siphalor.tweed5.patchwork.api.PatchworkFactory;
-import de.siphalor.tweed5.patchwork.impl.PatchworkClass;
-import de.siphalor.tweed5.patchwork.impl.PatchworkClassGenerator;
-import de.siphalor.tweed5.patchwork.impl.PatchworkClassPart;
-import de.siphalor.tweed5.weaver.pojo.api.annotation.PojoWeaving;
 import de.siphalor.tweed5.typeutils.api.type.ActualType;
+import de.siphalor.tweed5.weaver.pojo.api.annotation.PojoWeaving;
 import de.siphalor.tweed5.weaver.pojo.api.weaving.TweedPojoWeaver;
 import de.siphalor.tweed5.weaver.pojo.api.weaving.WeavingContext;
 import de.siphalor.tweed5.weaver.pojo.api.weaving.postprocess.TweedPojoWeavingPostProcessor;
-import lombok.*;
+import lombok.AccessLevel;
+import lombok.RequiredArgsConstructor;
 import lombok.extern.slf4j.Slf4j;
+import org.jspecify.annotations.Nullable;
 
 import java.lang.annotation.Annotation;
-import java.lang.invoke.MethodHandle;
+import java.util.Arrays;
-import java.util.*;
+import java.util.Collection;
 import java.util.stream.Collectors;
 
 /**
@@ -31,7 +30,8 @@ public class TweedPojoWeaverBootstrapper<T> {
 	private final ConfigContainer<T> configContainer;
 	private final Collection<TweedPojoWeaver> weavers;
 	private final Collection<TweedPojoWeavingPostProcessor> postProcessors;
-	private PatchworkClass<WeavingContext.ExtensionsData> contextExtensionsDataClass;
+	@Nullable
+	private PatchworkFactory contextExtensionsPatchworkFactory;
 
 	public static <T> TweedPojoWeaverBootstrapper<T> create(Class<T> pojoClass) {
 		PojoWeaving rootWeavingConfig = expectAnnotation(pojoClass, PojoWeaving.class);
@@ -88,44 +88,21 @@ public class TweedPojoWeaverBootstrapper<T> {
 	}
 
 	private void setupWeavers() {
-		Map<Class<?>, RegisteredExtensionDataImpl<?>> registeredExtensions = new HashMap<>();
+		PatchworkFactory.Builder contextExtensionsPatchworkFactoryBuilder = PatchworkFactory.builder();
 
-		TweedPojoWeaver.SetupContext setupContext = new TweedPojoWeaver.SetupContext() {
+		TweedPojoWeaver.SetupContext setupContext = contextExtensionsPatchworkFactoryBuilder::registerPart;
-			@Override
-			public <E> RegisteredExtensionData<WeavingContext.ExtensionsData, E> registerWeavingContextExtensionData(
-					Class<E> dataClass
-			) {
-				RegisteredExtensionDataImpl<E> registeredExtension = new RegisteredExtensionDataImpl<>();
-				registeredExtensions.put(dataClass, registeredExtension);
-				return registeredExtension;
-			}
-		};
 
 		for (TweedPojoWeaver weaver : weavers) {
 			weaver.setup(setupContext);
 		}
 
-		PatchworkClassCreator<WeavingContext.ExtensionsData> weavingContextCreator = PatchworkClassCreator.<WeavingContext.ExtensionsData>builder()
+		contextExtensionsPatchworkFactory = contextExtensionsPatchworkFactoryBuilder.build();
-				.classPackage(this.getClass().getPackage().getName() + ".generated")
-				.classPrefix("WeavingContext$")
-				.patchworkInterface(WeavingContext.ExtensionsData.class)
-				.build();
-
-		try {
-			this.contextExtensionsDataClass = weavingContextCreator.createClass(registeredExtensions.keySet());
-
-			for (PatchworkClassPart part : this.contextExtensionsDataClass.parts()) {
-				RegisteredExtensionDataImpl<?> registeredExtension = registeredExtensions.get(part.partInterface());
-				registeredExtension.setter(part.fieldSetter());
-			}
-		} catch (PatchworkClassGenerator.GenerationException e) {
-			throw new PojoWeavingException("Failed to create weaving context extensions data");
-		}
 	}
 
 	private WeavingContext createWeavingContext() {
 		try {
-			WeavingContext.ExtensionsData extensionsData = (WeavingContext.ExtensionsData) contextExtensionsDataClass.constructor().invoke();
+			assert contextExtensionsPatchworkFactory != null;
+			Patchwork extensionsData = contextExtensionsPatchworkFactory.create();
 
 			return WeavingContext.builder(this::weaveEntry, configContainer)
 					.extensionsData(extensionsData)
@@ -157,18 +134,4 @@ public class TweedPojoWeaverBootstrapper<T> {
 			}
 		}
 	}
-
-	@Setter
-	private static class RegisteredExtensionDataImpl<E> implements RegisteredExtensionData<WeavingContext.ExtensionsData, E> {
-		private MethodHandle setter;
-
-		@Override
-		public void set(WeavingContext.ExtensionsData patchwork, E extension) {
-			try {
-				setter.invokeWithArguments(patchwork, extension);
-			} catch (Throwable e) {
-				throw new IllegalStateException(e);
-			}
-		}
-	}
 }

tweed5-weaver-pojo/src/test/java/de/siphalor/tweed5/weaver/pojo/api/weaving/CompoundPojoWeaverTest.java

@@ -2,24 +2,18 @@ package de.siphalor.tweed5.weaver.pojo.api.weaving;
 
 import de.siphalor.tweed5.core.api.container.ConfigContainer;
 import de.siphalor.tweed5.core.api.entry.ConfigEntry;
-import de.siphalor.tweed5.core.api.entry.SimpleConfigEntry;
-import de.siphalor.tweed5.core.api.extension.RegisteredExtensionData;
 import de.siphalor.tweed5.core.impl.entry.SimpleConfigEntryImpl;
-import de.siphalor.tweed5.namingformat.api.NamingFormat;
+import de.siphalor.tweed5.patchwork.api.PatchworkFactory;
-import de.siphalor.tweed5.weaver.pojo.api.annotation.CompoundWeaving;
-import de.siphalor.tweed5.weaver.pojo.api.entry.WeavableCompoundConfigEntry;
 import de.siphalor.tweed5.typeutils.api.type.ActualType;
-import de.siphalor.tweed5.weaver.pojo.impl.weaving.compound.CompoundWeavingConfig;
+import de.siphalor.tweed5.weaver.pojo.api.annotation.CompoundWeaving;
-import lombok.AllArgsConstructor;
 import org.jetbrains.annotations.NotNull;
-import org.jetbrains.annotations.Nullable;
 import org.jspecify.annotations.NullUnmarked;
 import org.junit.jupiter.api.Test;
 
 import static de.siphalor.tweed5.weaver.pojo.test.ConfigEntryAssertions.isCompoundEntryForClassWith;
 import static de.siphalor.tweed5.weaver.pojo.test.ConfigEntryAssertions.isSimpleEntryForClass;
 import static org.assertj.core.api.Assertions.assertThat;
-import static org.mockito.Mockito.*;
+import static org.mockito.Mockito.mock;
 
 @SuppressWarnings("unused")
 @NullUnmarked
@@ -27,13 +21,12 @@ class CompoundPojoWeaverTest {
 
 	@Test
 	void weave() {
+		PatchworkFactory.Builder weavingContextExtensionDataFactoryBuilder = PatchworkFactory.builder();
+
 		CompoundPojoWeaver compoundWeaver = new CompoundPojoWeaver();
-		compoundWeaver.setup(new TweedPojoWeaver.SetupContext() {
+		compoundWeaver.setup(weavingContextExtensionDataFactoryBuilder::registerPart);
-			@Override
+
-			public <E> RegisteredExtensionData<WeavingContext.ExtensionsData, E> registerWeavingContextExtensionData(Class<E> dataClass) {
+		PatchworkFactory weavingContextExtensionDataFactory = weavingContextExtensionDataFactoryBuilder.build();
-				return (patchwork, extension) -> ((ExtensionsDataMock) patchwork).weavingConfig = (CompoundWeavingConfig) extension;
-			}
-		});
 
 		WeavingContext weavingContext = WeavingContext.builder(new TweedPojoWeavingFunction.NonNull() {
 					@Override
@@ -46,7 +39,7 @@ class CompoundPojoWeaverTest {
 						}
 					}
 				}, mock(ConfigContainer.class))
-				.extensionsData(new ExtensionsDataMock(null))
+				.extensionsData(weavingContextExtensionDataFactory.create())
 				.annotations(Compound.class)
 				.build();
 
@@ -86,39 +79,4 @@ class CompoundPojoWeaverTest {
 	public static class InnerValue {
 		public Integer value;
 	}
-
-	@AllArgsConstructor
-	private static class ExtensionsDataMock implements WeavingContext.ExtensionsData, CompoundWeavingConfig {
-		private CompoundWeavingConfig weavingConfig;
-
-		@Override
-		public boolean isPatchworkPartDefined(Class<?> patchworkInterface) {
-			return patchworkInterface == CompoundWeavingConfig.class;
-		}
-
-		@Override
-		public boolean isPatchworkPartSet(Class<?> patchworkInterface) {
-			return weavingConfig != null;
-		}
-
-		@Override
-		public WeavingContext.ExtensionsData copy() {
-			return new ExtensionsDataMock(weavingConfig);
-		}
-
-		@Override
-		public NamingFormat compoundSourceNamingFormat() {
-			return weavingConfig.compoundSourceNamingFormat();
-		}
-
-		@Override
-		public NamingFormat compoundTargetNamingFormat() {
-			return weavingConfig.compoundTargetNamingFormat();
-		}
-
-		@Override
-		public @Nullable Class<? extends WeavableCompoundConfigEntry> compoundEntryClass() {
-			return weavingConfig.compoundEntryClass();
-		}
-	}
 }