[serde-*, read-write-*] Support for visiting arbitrary decorations and values

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

@@ -7,8 +7,7 @@ import de.siphalor.tweed5.core.api.entry.ConfigEntry;
 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.extension.ReadWriteExtensionSetupContext;
-import de.siphalor.tweed5.data.extension.api.TweedEntryWriter;
 import de.siphalor.tweed5.data.extension.api.extension.ReadWriteRelatedExtension;
 import de.siphalor.tweed5.defaultextensions.comment.api.CommentExtension;
 import de.siphalor.tweed5.defaultextensions.comment.api.CommentModifyingExtension;
@@ -24,6 +23,8 @@ public class CommentExtensionImpl implements ReadWriteRelatedExtension, CommentE
 	@Getter
 	private final PatchworkPartAccess<CustomEntryData> customEntryDataAccess;
 	private final DefaultMiddlewareContainer<CommentProducer> middlewareContainer;
+	@Getter
+	private @Nullable PatchworkPartAccess<Boolean> writerInstalledReadWriteContextAccess;
 
 	public CommentExtensionImpl(ConfigContainer<?> configContainer, TweedExtensionSetupContext context) {
 		this.configContainer = configContainer;
@@ -47,8 +48,9 @@ public class CommentExtensionImpl implements ReadWriteRelatedExtension, CommentE
 	}
 
 	@Override
-	public @Nullable Middleware<TweedEntryWriter<?, ?>> entryWriterMiddleware() {
+	public void setupReadWriteExtension(ReadWriteExtensionSetupContext context) {
-		return new TweedEntryWriterCommentMiddleware(this);
+		writerInstalledReadWriteContextAccess = context.registerReadWriteContextExtensionData(Boolean.class);
+		context.registerWriterMiddleware(new TweedEntryWriterCommentMiddleware(this));
 	}
 
 	@Override

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

@@ -1,18 +1,24 @@
 package de.siphalor.tweed5.defaultextensions.comment.impl;
 
-import de.siphalor.tweed5.core.api.entry.CompoundConfigEntry;
 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.DelegatingTweedDataVisitor;
 import de.siphalor.tweed5.dataapi.api.TweedDataVisitor;
-import de.siphalor.tweed5.defaultextensions.comment.api.CommentExtension;
+import de.siphalor.tweed5.dataapi.api.decoration.TweedDataCommentDecoration;
+import de.siphalor.tweed5.dataapi.api.decoration.TweedDataDecoration;
+import de.siphalor.tweed5.patchwork.api.PatchworkPartAccess;
 import lombok.RequiredArgsConstructor;
+import lombok.Value;
 import org.jspecify.annotations.NonNull;
 import org.jspecify.annotations.Nullable;
 
+import java.util.ArrayDeque;
+import java.util.Deque;
+
 @RequiredArgsConstructor
 class TweedEntryWriterCommentMiddleware implements Middleware<TweedEntryWriter<?, ?>> {
-	private final CommentExtension commentExtension;
+	private final CommentExtensionImpl commentExtension;
 
 	@Override
 	public String id() {
@@ -21,122 +27,73 @@ class TweedEntryWriterCommentMiddleware implements Middleware<TweedEntryWriter<?
 
 	@Override
 	public TweedEntryWriter<?, ?> process(TweedEntryWriter<?, ?> inner) {
+		PatchworkPartAccess<Boolean> writerInstalledAccess = commentExtension.writerInstalledReadWriteContextAccess();
+		assert writerInstalledAccess != null;
+
 		//noinspection unchecked
 		TweedEntryWriter<Object, ConfigEntry<Object>> innerCasted = (TweedEntryWriter<Object, @NonNull ConfigEntry<Object>>) inner;
 		return (TweedEntryWriter<Object, @NonNull ConfigEntry<Object>>) (writer, value, entry, context) -> {
-			if (writer instanceof CompoundDataVisitor) {
+			if (!Boolean.TRUE.equals(context.extensionsData().get(writerInstalledAccess))) {
-				// Comment is already written in front of the key by the CompoundDataWriter,
+				context.extensionsData().set(writerInstalledAccess, Boolean.TRUE);
-				// so we don't have to write it here.
+
-				// We also want to unwrap the original writer,
+				writer = new MapEntryKeyDeferringWriter(writer);
-				// so that the special comment writing is limited to compounds.
-				writer = ((CompoundDataVisitor) writer).delegate;
-			} else {
-				String comment = getEntryComment(entry);
-				if (comment != null) {
-					writer.visitComment(comment);
-				}
 			}
 
-			if (entry instanceof CompoundConfigEntry) {
+			String comment = commentExtension.getFullComment(entry);
-				innerCasted.write(
+			if (comment != null) {
-						new CompoundDataVisitor(writer, ((CompoundConfigEntry<?>) entry)),
+				writer.visitDecoration(new PiercingCommentDecoration(() -> comment));
-						value,
-						entry,
-						context
-				);
-			} else {
-				innerCasted.write(writer, value, entry, context);
 			}
+
+			innerCasted.write(writer, value, entry, context);
 		};
 	}
 
-	@RequiredArgsConstructor
+	private static class MapEntryKeyDeferringWriter extends DelegatingTweedDataVisitor {
-	private class CompoundDataVisitor implements TweedDataVisitor {
+		private final Deque<TweedDataDecoration> decorationQueue = new ArrayDeque<>();
-		private final TweedDataVisitor delegate;
+		private @Nullable String mapEntryKey;
-		private final CompoundConfigEntry<?> compoundConfigEntry;
 
-		@Override
+		protected MapEntryKeyDeferringWriter(TweedDataVisitor delegate) {
-		public void visitNull() {
+			super(delegate);
-			delegate.visitNull();
-		}
-
-		@Override
-		public void visitBoolean(boolean value) {
-			delegate.visitBoolean(value);
-		}
-
-		@Override
-		public void visitByte(byte value) {
-			delegate.visitByte(value);
-		}
-
-		@Override
-		public void visitShort(short value) {
-			delegate.visitShort(value);
-		}
-
-		@Override
-		public void visitInt(int value) {
-			delegate.visitInt(value);
-		}
-
-		@Override
-		public void visitLong(long value) {
-			delegate.visitLong(value);
-		}
-
-		@Override
-		public void visitFloat(float value) {
-			delegate.visitFloat(value);
-		}
-
-		@Override
-		public void visitDouble(double value) {
-			delegate.visitDouble(value);
-		}
-
-		@Override
-		public void visitString(String value) {
-			delegate.visitString(value);
-		}
-
-		@Override
-		public void visitListStart() {
-			delegate.visitListStart();
-		}
-
-		@Override
-		public void visitListEnd() {
-			delegate.visitListEnd();
-		}
-
-		@Override
-		public void visitMapStart() {
-			delegate.visitMapStart();
 		}
 
 		@Override
 		public void visitMapEntryKey(String key) {
-			ConfigEntry<?> subEntry = compoundConfigEntry.subEntries().get(key);
+			if (mapEntryKey != null) {
-			String subEntryComment = getEntryComment(subEntry);
+				throw new IllegalStateException("Map entry key already visited");
-			if (subEntryComment != null) {
+			} else {
-				delegate.visitComment(subEntryComment);
+				mapEntryKey = key;
 			}
-			delegate.visitMapEntryKey(key);
 		}
 
 		@Override
-		public void visitMapEnd() {
+		public void visitDecoration(TweedDataDecoration decoration) {
-			delegate.visitMapEnd();
+			if (decoration instanceof PiercingCommentDecoration) {
+				super.visitDecoration(((PiercingCommentDecoration) decoration).commentDecoration());
+				return;
+			}
+			if (mapEntryKey != null) {
+				decorationQueue.addLast(decoration);
+			} else {
+				super.visitDecoration(decoration);
+			}
 		}
 
 		@Override
-		public void visitComment(String comment) {
+		protected void beforeValueWrite() {
-			delegate.visitComment(comment);
+			if (mapEntryKey != null) {
+				super.visitMapEntryKey(mapEntryKey);
+				mapEntryKey = null;
+				TweedDataDecoration decoration;
+				while ((decoration = decorationQueue.pollFirst()) != null) {
+					super.visitDecoration(decoration);
+				}
+			}
+			super.beforeValueWrite();
 		}
 	}
 
-	private @Nullable String getEntryComment(ConfigEntry<?> entry) {
+	@Value
-		return commentExtension.getFullComment(entry);
+	private static class PiercingCommentDecoration implements TweedDataDecoration {
+		TweedDataCommentDecoration commentDecoration;
 	}
 }

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

@@ -1,7 +1,10 @@
 package de.siphalor.tweed5.defaultextensions.pather.api;
 
+import de.siphalor.tweed5.dataapi.api.TweedDataUnsupportedValueException;
 import de.siphalor.tweed5.dataapi.api.TweedDataVisitor;
+import de.siphalor.tweed5.dataapi.api.decoration.TweedDataDecoration;
 import lombok.RequiredArgsConstructor;
+import org.jspecify.annotations.Nullable;
 
 @RequiredArgsConstructor
 public class PathTrackingDataVisitor implements TweedDataVisitor {
@@ -62,6 +65,12 @@ public class PathTrackingDataVisitor implements TweedDataVisitor {
 		valueVisited();
 	}
 
+	@Override
+	public void visitValue(@Nullable Object value) throws TweedDataUnsupportedValueException {
+		TweedDataVisitor.super.visitValue(value);
+		valueVisited();
+	}
+
 	private void valueVisited() {
 		if (pathTracking.currentContext() == PathTracking.Context.LIST) {
 			pathTracking.incrementListIndex();
@@ -103,7 +112,7 @@ public class PathTrackingDataVisitor implements TweedDataVisitor {
 	}
 
 	@Override
-	public void visitComment(String comment) {
+	public void visitDecoration(TweedDataDecoration decoration) {
-		delegate.visitComment(comment);
+		delegate.visitDecoration(decoration);
 	}
 }

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

@@ -23,9 +23,6 @@ import org.jspecify.annotations.Nullable;
 public class PatherExtensionImpl implements PatherExtension, TweedExtension, ReadWriteRelatedExtension {
 	private static final String PATHER_ID = "pather";
 
-	private final Middleware<TweedEntryReader<?, ?>> entryReaderMiddleware = createEntryReaderMiddleware();
-	private final Middleware<TweedEntryWriter<?, ?>> entryWriterMiddleware = createEntryWriterMiddleware();
-
 	private @Nullable PatchworkPartAccess<PathTracking> rwContextPathTrackingAccess;
 
 	@Override
@@ -36,6 +33,8 @@ public class PatherExtensionImpl implements PatherExtension, TweedExtension, Rea
 	@Override
 	public void setupReadWriteExtension(ReadWriteExtensionSetupContext context) {
 		rwContextPathTrackingAccess = context.registerReadWriteContextExtensionData(PathTracking.class);
+		context.registerReaderMiddleware(createEntryReaderMiddleware());
+		context.registerWriterMiddleware(createEntryWriterMiddleware());
 	}
 
 	@Override
@@ -144,14 +143,4 @@ public class PatherExtensionImpl implements PatherExtension, TweedExtension, Rea
 			}
 		};
 	}
-
-	@Override
-	public @Nullable Middleware<TweedEntryReader<?, ?>> entryReaderMiddleware() {
-		return entryReaderMiddleware;
-	}
-
-	@Override
-	public @Nullable Middleware<TweedEntryWriter<?, ?>> entryWriterMiddleware() {
-		return entryWriterMiddleware;
-	}
 }

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

@@ -134,6 +134,7 @@ public class ValidationExtensionImpl implements ReadWriteRelatedExtension, Valid
 	@Override
 	public void setupReadWriteExtension(ReadWriteExtensionSetupContext context) {
 		readContextValidationIssuesAccess = context.registerReadWriteContextExtensionData(ValidationIssues.class);
+		context.registerReaderMiddleware(new EntryValidationReaderMiddleware());
 	}
 
 	@Override
@@ -173,11 +174,6 @@ public class ValidationExtensionImpl implements ReadWriteRelatedExtension, Valid
 		return entryData;
 	}
 
-	@Override
-	public @Nullable Middleware<TweedEntryReader<?, ?>> entryReaderMiddleware() {
-		return new EntryValidationReaderMiddleware();
-	}
-
 	@Override
 	public <T> ValidationIssues validate(ConfigEntry<T> entry, @Nullable T value) {
 		PathTracking pathTracking = new PathTracking();

tweed5-serde-api/src/main/java/de/siphalor/tweed5/dataapi/api/DelegatingTweedDataVisitor.java

@@ -0,0 +1,118 @@
+package de.siphalor.tweed5.dataapi.api;
+
+import de.siphalor.tweed5.dataapi.api.decoration.TweedDataDecoration;
+import lombok.AccessLevel;
+import lombok.Getter;
+import lombok.RequiredArgsConstructor;
+import org.jspecify.annotations.Nullable;
+
+@Getter
+@RequiredArgsConstructor(access = AccessLevel.PROTECTED)
+public class DelegatingTweedDataVisitor implements TweedDataVisitor {
+	protected final TweedDataVisitor delegate;
+
+	@Override
+	public void visitNull() {
+		beforeValueWrite();
+		delegate.visitNull();
+	}
+
+	@Override
+	public void visitBoolean(boolean value) {
+		beforeValueWrite();
+		delegate.visitBoolean(value);
+	}
+
+	@Override
+	public void visitByte(byte value) {
+		beforeValueWrite();
+		delegate.visitByte(value);
+	}
+
+	@Override
+	public void visitShort(short value) {
+		beforeValueWrite();
+		delegate.visitShort(value);
+	}
+
+	@Override
+	public void visitInt(int value) {
+		beforeValueWrite();
+		delegate.visitInt(value);
+	}
+
+	@Override
+	public void visitLong(long value) {
+		beforeValueWrite();
+		delegate.visitLong(value);
+	}
+
+	@Override
+	public void visitFloat(float value) {
+		beforeValueWrite();
+		delegate.visitFloat(value);
+	}
+
+	@Override
+	public void visitDouble(double value) {
+		beforeValueWrite();
+		delegate.visitDouble(value);
+	}
+
+	@Override
+	public void visitString(String value) {
+		beforeValueWrite();
+		delegate.visitString(value);
+	}
+
+	@Override
+	public void visitEmptyList() {
+		beforeValueWrite();
+		delegate.visitEmptyList();
+	}
+
+	@Override
+	public void visitListStart() {
+		beforeValueWrite();
+		delegate.visitListStart();
+	}
+
+	@Override
+	public void visitListEnd() {
+		delegate.visitListEnd();
+	}
+
+	@Override
+	public void visitEmptyMap() {
+		beforeValueWrite();
+		delegate.visitEmptyMap();
+	}
+
+	@Override
+	public void visitMapStart() {
+		beforeValueWrite();
+		delegate.visitMapStart();
+	}
+
+	@Override
+	public void visitMapEntryKey(String key) {
+		delegate.visitMapEntryKey(key);
+	}
+
+	@Override
+	public void visitMapEnd() {
+		delegate.visitMapEnd();
+	}
+
+	@Override
+	public void visitValue(@Nullable Object value) throws TweedDataUnsupportedValueException {
+		delegate.visitValue(value);
+	}
+
+	protected void beforeValueWrite() {}
+
+	@Override
+	public void visitDecoration(TweedDataDecoration decoration) {
+		delegate.visitDecoration(decoration);
+	}
+}

tweed5-serde-api/src/main/java/de/siphalor/tweed5/dataapi/api/TweedDataUnsupportedValueException.java

@@ -0,0 +1,13 @@
+package de.siphalor.tweed5.dataapi.api;
+
+import lombok.Getter;
+
+@Getter
+public class TweedDataUnsupportedValueException extends Exception {
+	private final Object value;
+
+	public TweedDataUnsupportedValueException(Object value) {
+		super("Unsupported value " + value + " of type " + value.getClass().getName());
+		this.value = value;
+	}
+}

tweed5-serde-api/src/main/java/de/siphalor/tweed5/dataapi/api/TweedDataVisitor.java

@@ -1,5 +1,8 @@
 package de.siphalor.tweed5.dataapi.api;
 
+import de.siphalor.tweed5.dataapi.api.decoration.TweedDataDecoration;
+import org.jspecify.annotations.Nullable;
+
 public interface TweedDataVisitor {
 	void visitNull();
 	void visitBoolean(boolean value);
@@ -11,6 +14,43 @@ public interface TweedDataVisitor {
 	void visitDouble(double value);
 	void visitString(String value);
 
+	/**
+	 * Visits an arbitrary value.
+	 * <br />
+	 * This method is allowed to throw a {@link TweedDataUnsupportedValueException} for any value,
+	 * so call sites should <b>always</b> provide a fallback based on the primitive visitor methods.
+	 * @param value the value to visit. May be {@code null}.
+	 * @throws TweedDataUnsupportedValueException if the value is not supported by this visitor.
+	 * The visitor should then proceed to write the value with the primitive visitor methods.
+	 * @apiNote Please use the specific visitor methods if possible.
+	 * This method is mainly provided for extensibility beyond the standard data types.
+	 * This could, for example, be used to allow native support for {@link java.math.BigDecimal}
+	 * or {@link java.util.UUID} values.
+	 */
+	default void visitValue(@Nullable Object value) throws TweedDataUnsupportedValueException {
+		if (value == null) {
+			visitNull();
+		} else if (value instanceof Boolean) {
+			visitBoolean((Boolean) value);
+		} else if (value instanceof Byte) {
+			visitByte((Byte) value);
+		} else if (value instanceof Short) {
+			visitShort((Short) value);
+		} else if (value instanceof Integer) {
+			visitInt((Integer) value);
+		} else if (value instanceof Long) {
+			visitLong((Long) value);
+		} else if (value instanceof Float) {
+			visitFloat((Float) value);
+		} else if (value instanceof Double) {
+			visitDouble((Double) value);
+		} else if (value instanceof String) {
+			visitString((String) value);
+		} else {
+			throw new TweedDataUnsupportedValueException(value);
+		}
+	}
+
 	default void visitEmptyList() {
 		visitListStart();
 		visitListEnd();
@@ -26,5 +66,8 @@ public interface TweedDataVisitor {
 	void visitMapEntryKey(String key);
 	void visitMapEnd();
 
-	void visitComment(String comment);
+	/**
+	 * Visits a decoration. The implementation <b>may</b> choose to ignore the decoration.
+	 */
+	void visitDecoration(TweedDataDecoration decoration);
 }

tweed5-serde-api/src/main/java/de/siphalor/tweed5/dataapi/api/decoration/TweedDataCommentDecoration.java

@@ -0,0 +1,5 @@
+package de.siphalor.tweed5.dataapi.api.decoration;
+
+public interface TweedDataCommentDecoration extends TweedDataDecoration {
+	String comment();
+}

tweed5-serde-api/src/main/java/de/siphalor/tweed5/dataapi/api/decoration/TweedDataDecoration.java

@@ -0,0 +1,7 @@
+package de.siphalor.tweed5.dataapi.api.decoration;
+
+/**
+ * Marker interface for "decorative" information during (de)serialization.
+ */
+public interface TweedDataDecoration {
+}

tweed5-serde-api/src/main/java/de/siphalor/tweed5/dataapi/api/decoration/package-info.java

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

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

@@ -7,5 +7,6 @@ import org.jspecify.annotations.Nullable;
 
 @FunctionalInterface
 public interface TweedEntryWriter<T extends @Nullable Object, C extends ConfigEntry<T>> {
-	void write(TweedDataVisitor writer, @Nullable T value, C entry, TweedWriteContext context) throws TweedEntryWriteException, TweedDataWriteException;
+	void write(TweedDataVisitor writer, @Nullable T value, C entry, TweedWriteContext context)
+			throws TweedEntryWriteException, TweedDataWriteException;
 }

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

@@ -1,7 +1,12 @@
 package de.siphalor.tweed5.data.extension.api.extension;
 
+import de.siphalor.tweed5.core.api.middleware.Middleware;
+import de.siphalor.tweed5.data.extension.api.TweedEntryReader;
+import de.siphalor.tweed5.data.extension.api.TweedEntryWriter;
 import de.siphalor.tweed5.patchwork.api.PatchworkPartAccess;
 
 public interface ReadWriteExtensionSetupContext {
 	<E> PatchworkPartAccess<E> registerReadWriteContextExtensionData(Class<E> extensionDataClass);
+	void registerReaderMiddleware(Middleware<TweedEntryReader<?, ?>> middleware);
+	void registerWriterMiddleware(Middleware<TweedEntryWriter<?, ?>> middleware);
 }

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

@@ -1,22 +1,6 @@
 package de.siphalor.tweed5.data.extension.api.extension;
 
-import de.siphalor.tweed5.core.api.middleware.Middleware;
-import de.siphalor.tweed5.data.extension.api.TweedEntryReader;
-import de.siphalor.tweed5.data.extension.api.TweedEntryWriter;
-import org.jspecify.annotations.Nullable;
-
 public interface ReadWriteRelatedExtension {
 	default void setupReadWriteExtension(ReadWriteExtensionSetupContext context) {
-
-	}
-
-	@Nullable
-	default Middleware<TweedEntryReader<?, ?>> entryReaderMiddleware() {
-		return null;
-	}
-
-	@Nullable
-	default Middleware<TweedEntryWriter<?, ?>> entryWriterMiddleware() {
-		return null;
 	}
 }

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

@@ -6,6 +6,7 @@ import de.siphalor.tweed5.core.api.entry.ConfigEntry;
 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.*;
 import de.siphalor.tweed5.data.extension.api.extension.ReadWriteExtensionSetupContext;
 import de.siphalor.tweed5.data.extension.api.extension.ReadWriteRelatedExtension;
@@ -16,7 +17,6 @@ import de.siphalor.tweed5.patchwork.api.Patchwork;
 import de.siphalor.tweed5.patchwork.api.PatchworkFactory;
 import de.siphalor.tweed5.patchwork.api.PatchworkPartAccess;
 import lombok.Data;
-import lombok.val;
 import org.jspecify.annotations.Nullable;
 
 import java.util.Collection;
@@ -48,25 +48,29 @@ public class ReadWriteExtensionImpl implements ReadWriteExtension {
 		Collection<TweedExtension> extensions = configContainer.extensions();
 
 		PatchworkFactory.Builder readWriteContextPatchworkFactorBuilder = PatchworkFactory.builder();
-		ReadWriteExtensionSetupContext setupContext = readWriteContextPatchworkFactorBuilder::registerPart;
-
 		entryReaderMiddlewareContainer = new DefaultMiddlewareContainer<>();
 		entryWriterMiddlewareContainer = new DefaultMiddlewareContainer<>();
 
+		ReadWriteExtensionSetupContext setupContext = new ReadWriteExtensionSetupContext() {
+			@Override
+			public <E> PatchworkPartAccess<E> registerReadWriteContextExtensionData(Class<E> extensionDataClass) {
+				return readWriteContextPatchworkFactorBuilder.registerPart(extensionDataClass);
+			}
+
+			@Override
+			public void registerReaderMiddleware(Middleware<TweedEntryReader<?, ?>> middleware) {
+				entryReaderMiddlewareContainer.register(middleware);
+			}
+
+			@Override
+			public void registerWriterMiddleware(Middleware<TweedEntryWriter<?, ?>> middleware) {
+				entryWriterMiddlewareContainer.register(middleware);
+			}
+		};
+
 		for (TweedExtension extension : extensions) {
 			if (extension instanceof ReadWriteRelatedExtension) {
-				ReadWriteRelatedExtension rwExtension = (ReadWriteRelatedExtension) extension;
+				((ReadWriteRelatedExtension) extension).setupReadWriteExtension(setupContext);
-
-				rwExtension.setupReadWriteExtension(setupContext);
-
-				val readerMiddleware = rwExtension.entryReaderMiddleware();
-				if (readerMiddleware != null) {
-					entryReaderMiddlewareContainer.register(readerMiddleware);
-				}
-				val writerMiddleware = rwExtension.entryWriterMiddleware();
-				if (writerMiddleware != null) {
-					entryWriterMiddlewareContainer.register(writerMiddleware);
-				}
 			}
 		}
 

tweed5-serde-hjson/src/main/java/de/siphalor/tweed5/data/hjson/HjsonWriter.java

@@ -2,6 +2,8 @@ package de.siphalor.tweed5.data.hjson;
 
 import de.siphalor.tweed5.dataapi.api.TweedDataWriteException;
 import de.siphalor.tweed5.dataapi.api.TweedDataVisitor;
+import de.siphalor.tweed5.dataapi.api.decoration.TweedDataCommentDecoration;
+import de.siphalor.tweed5.dataapi.api.decoration.TweedDataDecoration;
 import lombok.Data;
 
 import java.io.IOException;
@@ -237,7 +239,13 @@ public class HjsonWriter implements TweedDataVisitor {
 	}
 
 	@Override
-	public void visitComment(String comment) {
+	public void visitDecoration(TweedDataDecoration decoration) {
+		if (decoration instanceof TweedDataCommentDecoration) {
+			visitComment(((TweedDataCommentDecoration) decoration).comment());
+		}
+	}
+
+	private void visitComment(String comment) {
 		Matcher lineFeedMatcher = LINE_FEED_PATTERN.matcher(comment);
 		if (lineFeedMatcher.find()) {
 			// Multiline