refactor!(serde-extension): Fundamentally change error handling for data reading

tweed5-minecraft/coat-bridge/src/main/java/de/siphalor/tweed5/coat/bridge/impl/TweedCoatMappersImpl.java

@@ -1,6 +1,7 @@
 package de.siphalor.tweed5.coat.bridge.impl;
 
 import de.siphalor.coat.handler.ConfigEntryHandler;
+import de.siphalor.coat.handler.Message;
 import de.siphalor.coat.input.CheckBoxConfigInput;
 import de.siphalor.coat.input.ConfigInput;
 import de.siphalor.coat.input.CycleButtonConfigInput;
@@ -20,22 +21,23 @@ import de.siphalor.tweed5.coat.bridge.api.mapping.handler.BasicTweedCoatEntryHan
 import de.siphalor.tweed5.coat.bridge.api.mapping.handler.ConvertingTweedCoatEntryHandler;
 import de.siphalor.tweed5.core.api.entry.CompoundConfigEntry;
 import de.siphalor.tweed5.core.api.entry.ConfigEntry;
+import de.siphalor.tweed5.patchwork.api.Patchwork;
 import de.siphalor.tweed5.serde.extension.api.ReadWriteExtension;
-import de.siphalor.tweed5.serde.extension.api.TweedEntryReadException;
 import de.siphalor.tweed5.serde.extension.api.TweedEntryReader;
 import de.siphalor.tweed5.serde.extension.api.TweedReadContext;
+import de.siphalor.tweed5.serde.extension.api.read.result.TweedReadResult;
 import de.siphalor.tweed5.serde_api.api.TweedDataReadException;
 import de.siphalor.tweed5.serde_api.api.TweedDataReader;
 import de.siphalor.tweed5.serde_api.api.TweedDataToken;
 import de.siphalor.tweed5.serde_api.api.TweedDataVisitor;
 import de.siphalor.tweed5.serde_api.api.decoration.TweedDataDecoration;
-import de.siphalor.tweed5.patchwork.api.Patchwork;
 import lombok.RequiredArgsConstructor;
 import lombok.Value;
 import lombok.extern.apachecommons.CommonsLog;
 import net.minecraft.ChatFormatting;
 import net.minecraft.client.Minecraft;
 import net.minecraft.client.resources.language.I18n;
+import net.minecraft.network.chat.Component;
 import net.minecraft.resources.ResourceLocation;
 import org.jspecify.annotations.NonNull;
 import org.jspecify.annotations.Nullable;
@@ -44,8 +46,7 @@ import java.util.*;
 import java.util.function.Function;
 import java.util.stream.Collectors;
 
-import static de.siphalor.tweed5.coat.bridge.api.TweedCoatMappingUtils.translatableComponent;
-import static de.siphalor.tweed5.coat.bridge.api.TweedCoatMappingUtils.translatableComponentWithFallback;
+import static de.siphalor.tweed5.coat.bridge.api.TweedCoatMappingUtils.*;
 
 @CommonsLog
 @SuppressWarnings("unchecked")
@@ -133,66 +134,71 @@ public class TweedCoatMappersImpl {
 					if (context.parentSaveHandler() == null) {
 						throw new IllegalArgumentException("No parent save handler provided");
 					}
-					return new ConvertingTweedCoatEntryHandler<>(
-							new BasicTweedCoatEntryHandler<>(entry, context.defaultValue(), context.parentSaveHandler()),
-							this::convertToString,
-							input -> {
+					return new ConfigEntryHandler<String>() {
+						@Override
+						public String getDefault() {
+							return convertToString(context.defaultValue());
+						}
+
+						@Override
+						public Collection<Message> getMessages(String text) {
 							try {
-									TweedEntryReader<T, ConfigEntry<T>> reader =
-											readWriteExtension.getDefinedEntryReader(entry);
-									Patchwork readExtData = readWriteExtension.createReadWriteContextExtensionsData();
-									//noinspection DataFlowIssue
-									return reader.read(
-											new TweedDataReader() {
-												private boolean consumed = false;
-
-												@Override
-												public TweedDataToken peekToken() throws TweedDataReadException {
-													if (consumed) {
-														throw new IllegalStateException("Already consumed");
+								TweedReadResult<T> readResult = convertFromString(text);
+								if (readResult.hasValue() && !readResult.hasIssues()) {
+									return Collections.emptyList();
+								} else if (readResult.hasIssues()) {
+									Message.Level messageLevel = readResult.hasValue()
+											? Message.Level.WARNING
+											: Message.Level.ERROR;
+									return Arrays.stream(readResult.issues()).map(issue ->
+											new Message(messageLevel, literalComponent(issue.exception().getMessage()))
+									).collect(Collectors.toList());
+								} else {
+									return Collections.emptyList();
+								}
+							} catch (Exception e) {
+								return Collections.singletonList(
+										new Message(Message.Level.ERROR, literalComponent(e.getMessage()))
+								);
 							}
-													return new TweedDataToken() {
-														@Override
-														public boolean canReadAsString() {
-															return true;
 						}
 
 						@Override
-														public String readAsString() {
-															return input;
+						public void save(String s) {
+							try {
+								TweedReadResult<T> readResult = convertFromString(s);
+								if (readResult.hasValue()) {
+									if (readResult.hasIssues()) {
+										log.warn(
+												"There were issues understanding value \"" + s + "\":\n  - "
+														+ Arrays.stream(readResult.issues())
+														.map(issue -> issue.exception().getMessage())
+														.collect(Collectors.joining("\n  - "))
+										);
+									}
+									context.parentSaveHandler().accept(readResult.value());
+								} else {
+									log.error(
+											"Failed to understand value \"" + s + "\":\n  - "
+													+ Arrays.stream(readResult.issues())
+													.map(issue -> issue.exception().getMessage())
+													.collect(Collectors.joining("\n  - "))
+									);
+									context.parentSaveHandler().accept(context.defaultValue());
+								}
+							} catch (Exception e) {
+								log.error("Failed to save value \"" + s + "\"", e);
+								context.parentSaveHandler().accept(context.defaultValue());
+							}
+						}
+
+						@Override
+						public Component asText(String text) {
+							return literalComponent(text);
 						}
 					};
 				}
 
-												@Override
-												public TweedDataToken readToken() throws TweedDataReadException {
-													TweedDataToken token = peekToken();
-													consumed = true;
-													return token;
-												}
-
-												@Override
-												public void close() {
-												}
-											}, entry, new TweedReadContext() {
-												@Override
-												public ReadWriteExtension readWriteExtension() {
-													return readWriteExtension;
-												}
-
-												@Override
-												public Patchwork extensionsData() {
-													return readExtData;
-												}
-											}
-									);
-								} catch (TweedEntryReadException e) {
-									throw new RuntimeException(e.getMessage(), e);
-								}
-							}
-					);
-				}
-
 				@Override
 				public @Nullable ConfigContentWidget createContentWidget(TweedCoatEntryCreationContext<T> context) {
 					return null;
@@ -270,6 +276,57 @@ public class TweedCoatMappersImpl {
 					}
 					return wrapper[0];
 				}
+
+				private TweedReadResult<T> convertFromString(String text) {
+					TweedEntryReader<T, ConfigEntry<T>> reader =
+							readWriteExtension.getDefinedEntryReader(entry);
+					Patchwork readExtData = readWriteExtension.createReadWriteContextExtensionsData();
+					//noinspection DataFlowIssue
+					return reader.read(
+							new TweedDataReader() {
+								private boolean consumed = false;
+
+								@Override
+								public TweedDataToken peekToken() throws TweedDataReadException {
+									if (consumed) {
+										throw new IllegalStateException("Already consumed");
+									}
+									return new TweedDataToken() {
+										@Override
+										public boolean canReadAsString() {
+											return true;
+										}
+
+										@Override
+										public String readAsString() {
+											return text;
+										}
+									};
+								}
+
+								@Override
+								public TweedDataToken readToken() throws TweedDataReadException {
+									TweedDataToken token = peekToken();
+									consumed = true;
+									return token;
+								}
+
+								@Override
+								public void close() {
+								}
+							}, entry, new TweedReadContext() {
+								@Override
+								public ReadWriteExtension readWriteExtension() {
+									return readWriteExtension;
+								}
+
+								@Override
+								public Patchwork extensionsData() {
+									return readExtData;
+								}
+							}
+					);
+				}
 			};
 		}
 	}

tweed5-minecraft/coat-bridge/src/testmod/java/de/siphalor/tweed5/coat/bridge/testmod/TweedCoatBridgeTestMod.java

@@ -58,9 +58,9 @@ public class TweedCoatBridgeTestMod implements ClientModInitializer {
 				MOD_ID + ".config",
 				GLFW.GLFW_KEY_T,
 				//# if MC_VERSION_NUMBER >= 12109
-				//- KeyMapping.Category.MISC
+				KeyMapping.Category.MISC
 				//# else
-				"key.categories.misc"
+				//- "key.categories.misc"
 				//# end
 		));
 
@@ -69,9 +69,9 @@ public class TweedCoatBridgeTestMod implements ClientModInitializer {
 
 	private class ScreenKeyBinding extends KeyMapping implements PriorityKeyBinding {
 		//# if MC_VERSION_NUMBER >= 12109
-		//- public ScreenKeyBinding(String name, int key, Category category) {
+		public ScreenKeyBinding(String name, int key, Category category) {
 		//# else
-		public ScreenKeyBinding(String name, int key, String category) {
+		//- public ScreenKeyBinding(String name, int key, String category) {
 		//# end
 			super(name, key, category);
 		}

tweed5-minecraft/fabric-helper/src/main/java/de/siphalor/tweed5/fabric/helper/api/FabricConfigContainerHelper.java

@@ -2,22 +2,22 @@ package de.siphalor.tweed5.fabric.helper.api;
 
 import de.siphalor.tweed5.core.api.container.ConfigContainer;
 import de.siphalor.tweed5.core.api.container.ConfigContainerSetupPhase;
-import de.siphalor.tweed5.serde.extension.api.ReadWriteExtension;
-import de.siphalor.tweed5.serde_api.api.TweedDataReader;
-import de.siphalor.tweed5.serde_api.api.TweedDataWriter;
-import de.siphalor.tweed5.serde_api.api.TweedSerde;
 import de.siphalor.tweed5.defaultextensions.patch.api.PatchExtension;
 import de.siphalor.tweed5.defaultextensions.patch.api.PatchInfo;
 import de.siphalor.tweed5.defaultextensions.presets.api.PresetsExtension;
 import de.siphalor.tweed5.patchwork.api.Patchwork;
+import de.siphalor.tweed5.serde.extension.api.ReadWriteExtension;
+import de.siphalor.tweed5.serde.extension.api.read.result.TweedReadIssue;
+import de.siphalor.tweed5.serde.extension.api.read.result.TweedReadResult;
+import de.siphalor.tweed5.serde_api.api.TweedDataReader;
+import de.siphalor.tweed5.serde_api.api.TweedDataWriter;
+import de.siphalor.tweed5.serde_api.api.TweedSerde;
 import lombok.Getter;
 import lombok.extern.apachecommons.CommonsLog;
 import net.fabricmc.loader.api.FabricLoader;
 import org.jspecify.annotations.Nullable;
 
 import java.io.File;
-import java.io.FileInputStream;
-import java.io.FileOutputStream;
 import java.io.IOException;
 import java.nio.file.Files;
 import java.nio.file.Path;
@@ -84,14 +84,24 @@ public class FabricConfigContainerHelper<T extends @Nullable Object> {
 			return;
 		}
 
-		try (TweedDataReader reader = serde.createReader(new FileInputStream(configFile))) {
+		try (TweedDataReader reader = serde.createReader(Files.newInputStream(configFile.toPath()))) {
 			Patchwork contextExtensionsData = readWriteExtension.createReadWriteContextExtensionsData();
 			readContextCustomizer.accept(contextExtensionsData);
 			PatchInfo patchInfo = patchExtension.collectPatchInfo(contextExtensionsData);
 
-			T readValue = readWriteExtension.read(reader, configContainer().rootEntry(), contextExtensionsData);
+			TweedReadResult<T> readResult = readWriteExtension.read(reader, configContainer().rootEntry(), contextExtensionsData);
+			if (readResult.hasValue()) {
+				patchExtension.patch(configContainer.rootEntry(), value, readResult.value(), patchInfo);
+
+				if (readResult.hasIssues()) {
+					log.warn(formatIssuesLogMessage(configFile, "issues", readResult.issues()));
+				}
+			} else if (readResult.hasIssues()) {
+				log.error(formatIssuesLogMessage(configFile, "errors", readResult.issues()));
+			} else {
+				log.debug("Reading config file " + configFile.getAbsolutePath() + " yielded empty result");
+			}
 
-			patchExtension.patch(configContainer.rootEntry(), value, readValue, patchInfo);
 		} catch (Exception e) {
 			log.error("Failed loading config file " + configFile.getAbsolutePath(), e);
 		}
@@ -108,20 +118,54 @@ public class FabricConfigContainerHelper<T extends @Nullable Object> {
 			return defaultValueSupplier.get();
 		}
 
-		try (TweedDataReader reader = serde.createReader(new FileInputStream(configFile))) {
+		try (TweedDataReader reader = serde.createReader(Files.newInputStream(configFile.toPath()))) {
 			Patchwork contextExtensionsData = readWriteExtension.createReadWriteContextExtensionsData();
-			return readWriteExtension.read(reader, configContainer.rootEntry(), contextExtensionsData);
+			TweedReadResult<T> readResult = readWriteExtension.read(
+					reader,
+					configContainer.rootEntry(),
+					contextExtensionsData
+			);
+			if (readResult.hasValue()) {
+				if (readResult.hasIssues()) {
+					log.warn(formatIssuesLogMessage(configFile, "issues", readResult.issues()));
+				}
+				return readResult.value();
+			} else if (readResult.hasIssues()) {
+				log.error(formatIssuesLogMessage(configFile, "errors", readResult.issues()));
+			} else {
+				log.info(
+						"Reading config file "
+								+ configFile.getAbsolutePath()
+								+ " yielded empty result, using default value"
+				);
+			}
+			return defaultValueSupplier.get();
 		} catch (Exception e) {
 			log.error("Failed loading config file " + configFile.getAbsolutePath(), e);
 			return defaultValueSupplier.get();
 		}
 	}
 
+	private String formatIssuesLogMessage(File file, String type, TweedReadIssue[] issues) {
+		String filePath = file.getAbsolutePath();
+
+		StringBuilder stringBuilder = new StringBuilder(20 + filePath.length() + type.length() + issues.length * 50);
+		stringBuilder.append("Encountered ");
+		stringBuilder.append(type);
+		stringBuilder.append(" while reading ");
+		stringBuilder.append(filePath);
+		stringBuilder.append(": ");
+		for (TweedReadIssue issue : issues) {
+			stringBuilder.append("  - ").append(issue).append("\n");
+		}
+		return stringBuilder.toString();
+	}
+
 	public void writeConfigInConfigDirectory(T configValue) {
 		File configFile = getConfigFile();
 		Path tempConfigDirectory = getOrCreateTempConfigDirectory();
 		File tempConfigFile = tempConfigDirectory.resolve(getConfigFileName()).toFile();
-		try (TweedDataWriter writer = serde.createWriter(new FileOutputStream(tempConfigFile))) {
+		try (TweedDataWriter writer = serde.createWriter(Files.newOutputStream(tempConfigFile.toPath()))) {
 			Patchwork contextExtensionsData = readWriteExtension.createReadWriteContextExtensionsData();
 
 			readWriteExtension.write(

tweed5/attributes-extension/src/main/java/de/siphalor/tweed5/attributesextension/impl/serde/filter/AttributesFilteredCompoundEntry.java

@@ -1,71 +0,0 @@
-package de.siphalor.tweed5.attributesextension.impl.serde.filter;
-
-import de.siphalor.tweed5.core.api.container.ConfigContainer;
-import de.siphalor.tweed5.core.api.entry.CompoundConfigEntry;
-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.patchwork.api.Patchwork;
-import lombok.RequiredArgsConstructor;
-import org.jspecify.annotations.NonNull;
-import org.jspecify.annotations.Nullable;
-
-import java.util.Map;
-
-@RequiredArgsConstructor
-public class AttributesFilteredCompoundEntry<T extends @Nullable Object> implements CompoundConfigEntry<T> {
-	private final CompoundConfigEntry<T> delegate;
-
-	@Override
-	public void set(T compoundValue, String key, Object value) {
-		if (value == AttributesReadWriteFilterExtensionImpl.NOOP_MARKER) {
-			return;
-		}
-		delegate.set(compoundValue, key, value);
-	}
-
-	@Override
-	public Object get(T compoundValue, String key) {
-		return delegate.get(compoundValue, key);
-	}
-
-	@Override
-	public @NonNull T instantiateValue() {
-		return delegate.instantiateValue();
-	}
-
-	@Override
-	public Map<String, ConfigEntry<?>> subEntries() {
-		return delegate.subEntries();
-	}
-
-	@Override
-	public ConfigContainer<?> container() {
-		return delegate.container();
-	}
-
-	@Override
-	public Class<T> valueClass() {
-		return delegate.valueClass();
-	}
-
-	@Override
-	public Patchwork extensionsData() {
-		return delegate.extensionsData();
-	}
-
-	@Override
-	public void visitInOrder(ConfigEntryValueVisitor visitor, T value) {
-		delegate.visitInOrder(visitor, value);
-	}
-
-	@Override
-	public void visitInOrder(ConfigEntryVisitor visitor) {
-		delegate.visitInOrder(visitor);
-	}
-
-	@Override
-	public T deepCopy(T value) {
-		return delegate.deepCopy(value);
-	}
-}

tweed5/attributes-extension/src/main/java/de/siphalor/tweed5/attributesextension/impl/serde/filter/AttributesReadWriteFilterExtensionImpl.java

@@ -5,25 +5,22 @@ import de.siphalor.tweed5.attributesextension.api.AttributesRelatedExtension;
 import de.siphalor.tweed5.attributesextension.api.serde.filter.AttributesReadWriteFilterExtension;
 import de.siphalor.tweed5.core.api.container.ConfigContainer;
 import de.siphalor.tweed5.core.api.container.ConfigContainerSetupPhase;
-import de.siphalor.tweed5.core.api.entry.CompoundConfigEntry;
 import de.siphalor.tweed5.core.api.entry.ConfigEntry;
 import de.siphalor.tweed5.core.api.entry.ConfigEntryVisitor;
 import de.siphalor.tweed5.core.api.extension.TweedExtensionSetupContext;
 import de.siphalor.tweed5.core.api.middleware.Middleware;
-import de.siphalor.tweed5.serde.extension.api.TweedEntryReadException;
+import de.siphalor.tweed5.patchwork.api.Patchwork;
+import de.siphalor.tweed5.patchwork.api.PatchworkPartAccess;
 import de.siphalor.tweed5.serde.extension.api.TweedEntryReader;
 import de.siphalor.tweed5.serde.extension.api.TweedEntryWriter;
-import de.siphalor.tweed5.serde.extension.api.TweedReadContext;
 import de.siphalor.tweed5.serde.extension.api.extension.ReadWriteExtensionSetupContext;
 import de.siphalor.tweed5.serde.extension.api.extension.ReadWriteRelatedExtension;
+import de.siphalor.tweed5.serde.extension.api.read.result.TweedReadResult;
 import de.siphalor.tweed5.serde.extension.impl.TweedEntryReaderWriterImpls;
 import de.siphalor.tweed5.serde_api.api.DelegatingTweedDataWriter;
-import de.siphalor.tweed5.serde_api.api.TweedDataReader;
 import de.siphalor.tweed5.serde_api.api.TweedDataUnsupportedValueException;
 import de.siphalor.tweed5.serde_api.api.TweedDataVisitor;
 import de.siphalor.tweed5.serde_api.api.decoration.TweedDataDecoration;
-import de.siphalor.tweed5.patchwork.api.Patchwork;
-import de.siphalor.tweed5.patchwork.api.PatchworkPartAccess;
 import de.siphalor.tweed5.utils.api.UniqueSymbol;
 import lombok.Getter;
 import lombok.RequiredArgsConstructor;
@@ -184,13 +181,7 @@ public class AttributesReadWriteFilterExtensionImpl
 			TweedEntryReader<Object, ConfigEntry<Object>> innerCasted
 					= (TweedEntryReader<Object, @NonNull ConfigEntry<Object>>) inner;
 
-			return new TweedEntryReader<@Nullable Object, ConfigEntry<Object>>() {
-				@Override
-				public @Nullable Object read(
-						TweedDataReader reader,
-						ConfigEntry<Object> entry,
-						TweedReadContext context
-				) throws TweedEntryReadException {
+			return (TweedEntryReader<Object, ConfigEntry<Object>>) (reader, entry, context) -> {
 				ReadWriteContextCustomData contextData = context.extensionsData().get(readWriteContextDataAccess);
 				if (contextData == null) {
 					contextData = new ReadWriteContextCustomData();
@@ -198,19 +189,9 @@ public class AttributesReadWriteFilterExtensionImpl
 				}
 				if (!doFiltersMatch(entry, contextData)) {
 					TweedEntryReaderWriterImpls.NOOP_READER_WRITER.read(reader, entry, context);
-						return contextData.noopHandlerInstalled() ? NOOP_MARKER : null;
-					}
-					if (entry instanceof CompoundConfigEntry) {
-						CompoundConfigEntry<Object> delegated =
-								new AttributesFilteredCompoundEntry<>(((CompoundConfigEntry<Object>) entry));
-						boolean oldNoopHandlerInstalled = contextData.noopHandlerInstalled();
-						contextData.noopHandlerInstalled(true);
-						Object value = innerCasted.read(reader, delegated, context);
-						contextData.noopHandlerInstalled(oldNoopHandlerInstalled);
-						return value;
+					return TweedReadResult.empty();
 				}
 				return innerCasted.read(reader, entry, context);
-				}
 			};
 		}
 	}

tweed5/attributes-extension/src/test/java/de/siphalor/tweed5/attributesextension/impl/serde/filter/AttributesReadWriteFilterExtensionImplTest.java

@@ -9,6 +9,7 @@ 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.serde.extension.api.ReadWriteExtension;
+import de.siphalor.tweed5.serde.extension.api.read.result.TweedReadResult;
 import de.siphalor.tweed5.serde.hjson.HjsonLexer;
 import de.siphalor.tweed5.serde.hjson.HjsonReader;
 import de.siphalor.tweed5.serde.hjson.HjsonWriter;
@@ -164,12 +165,14 @@ class AttributesReadWriteFilterExtensionImplTest {
 				}
 				}
 				""")));
-		Map<String, Object> readValue = configContainer.rootEntry().call(read(
+		TweedReadResult<Map<String, Object>> readResult = configContainer.rootEntry().call(read(
 				reader,
 				patchwork -> attributesReadWriteFilterExtension.addFilter(patchwork, "type", "a")
 		));
 
-		assertThat(readValue)
+		assertThat(readResult)
+				.extracting(TweedReadResult::value)
+				.asInstanceOf(map(String.class, Object.class))
 				.containsEntry("first", "1st")
 				.doesNotContainKey("second")
 				.hasEntrySatisfying(

tweed5/attributes-extension/src/test/java/de/siphalor/tweed5/attributesextension/impl/serde/filter/AttributesReadWriteFilterExtensionImplWithPatchInfoTest.java

@@ -7,6 +7,7 @@ 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.serde.extension.api.ReadWriteExtension;
+import de.siphalor.tweed5.serde.extension.api.read.result.TweedReadResult;
 import de.siphalor.tweed5.serde.hjson.HjsonLexer;
 import de.siphalor.tweed5.serde.hjson.HjsonReader;
 import de.siphalor.tweed5.defaultextensions.patch.api.PatchExtension;
@@ -25,6 +26,7 @@ import static de.siphalor.tweed5.serde.extension.api.readwrite.TweedEntryReaderW
 import static de.siphalor.tweed5.testutils.generic.MapTestUtils.sequencedMap;
 import static java.util.Map.entry;
 import static org.assertj.core.api.Assertions.assertThat;
+import static org.assertj.core.api.InstanceOfAssertFactories.map;
 
 public class AttributesReadWriteFilterExtensionImplWithPatchInfoTest {
 	@Test
@@ -65,7 +67,7 @@ public class AttributesReadWriteFilterExtensionImplWithPatchInfoTest {
 		var patchInfo = patchExtension.collectPatchInfo(readExtData);
 		filterExtension.addFilter(readExtData, "type", "a");
 
-		var value = readWriteExtension.read(
+		var readResult = readWriteExtension.read(
 				new HjsonReader(new HjsonLexer(new StringReader("""
 						{
 							"first": "FIRST",
@@ -76,8 +78,10 @@ public class AttributesReadWriteFilterExtensionImplWithPatchInfoTest {
 				readExtData
 		);
 
-		assertThat(value).extracting(v -> v.get("first")).isEqualTo("FIRST");
-		assertThat(value).extracting(v -> v.get("second")).isNull();
+		assertThat(readResult)
+				.extracting(TweedReadResult::value)
+				.asInstanceOf(map(String.class, Object.class))
+				.isEqualTo(Map.of("first", "FIRST"));
 		assertThat(patchInfo.containsEntry(firstEntry)).isTrue();
 		assertThat(patchInfo.containsEntry(secondEntry)).isFalse();
 	}

tweed5/default-extensions/src/main/java/de/siphalor/tweed5/defaultextensions/patch/impl/PatchExtensionImpl.java

@@ -3,12 +3,10 @@ package de.siphalor.tweed5.defaultextensions.patch.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.serde.extension.api.TweedEntryReadException;
 import de.siphalor.tweed5.serde.extension.api.TweedEntryReader;
-import de.siphalor.tweed5.serde.extension.api.TweedReadContext;
 import de.siphalor.tweed5.serde.extension.api.extension.ReadWriteExtensionSetupContext;
 import de.siphalor.tweed5.serde.extension.api.extension.ReadWriteRelatedExtension;
-import de.siphalor.tweed5.serde_api.api.TweedDataReader;
+import de.siphalor.tweed5.serde.extension.api.read.result.TweedReadResult;
 import de.siphalor.tweed5.defaultextensions.patch.api.PatchExtension;
 import de.siphalor.tweed5.defaultextensions.patch.api.PatchInfo;
 import de.siphalor.tweed5.patchwork.api.Patchwork;
@@ -96,20 +94,13 @@ public class PatchExtensionImpl implements PatchExtension, ReadWriteRelatedExten
 			//noinspection unchecked
 			TweedEntryReader<Object, ConfigEntry<Object>> innerCasted =
 					(TweedEntryReader<Object, @NonNull ConfigEntry<Object>>) inner;
-			return new TweedEntryReader<@Nullable Object, ConfigEntry<Object>>() {
-				@Override
-				public @Nullable Object read(
-						TweedDataReader reader,
-						ConfigEntry<Object> entry,
-						TweedReadContext context
-				) throws TweedEntryReadException {
-					Object readValue = innerCasted.read(reader, entry, context);
+			return (TweedEntryReader<Object, ConfigEntry<Object>>) (reader, entry, context) -> {
+				TweedReadResult<Object> readResult = innerCasted.read(reader, entry, context);
 				ReadWriteContextCustomData customData = context.extensionsData().get(readWriteContextDataAccess);
 				if (customData != null && customData.patchInfo() != null) {
 					customData.patchInfo().addEntry(entry);
 				}
-					return readValue;
-				}
+				return readResult;
 			};
 		}
 	}

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

@@ -70,21 +70,7 @@ public class PatherExtensionImpl implements PatherExtension, ReadWriteRelatedExt
 
 					pathTracking = PathTracking.create();
 					context.extensionsData().set(rwContextPathTrackingAccess, pathTracking);
-					try {
 					return castedInner.read(new PathTrackingDataReader(reader, pathTracking), entry, context);
-					} catch (TweedEntryReadException e) {
-						val exceptionPathTracking = e.context().extensionsData().get(rwContextPathTrackingAccess);
-						if (exceptionPathTracking != null) {
-							throw new TweedEntryReadException(
-									"Exception while reading entry at "
-											+ exceptionPathTracking.currentPath()
-											+ ": " + e.getMessage(),
-									e
-							);
-						} else {
-							throw e;
-						}
-					}
 				};
 			}
 		};
@@ -116,7 +102,8 @@ public class PatherExtensionImpl implements PatherExtension, ReadWriteRelatedExt
 					try {
 						castedInner.write(new PathTrackingDataVisitor(writer, pathTracking), value, entry, context);
 					} catch (TweedEntryWriteException e) {
-						val exceptionPathTracking = e.context().extensionsData().get(rwContextPathTrackingAccess);
+						PathTracking exceptionPathTracking =
+								e.context().extensionsData().get(rwContextPathTrackingAccess);
 						if (exceptionPathTracking != null) {
 							throw new TweedEntryWriteException(
 									"Exception while writing entry at "

tweed5/default-extensions/src/main/java/de/siphalor/tweed5/defaultextensions/readfallback/impl/ReadFallbackExtensionImpl.java

@@ -3,7 +3,6 @@ package de.siphalor.tweed5.defaultextensions.readfallback.impl;
 import de.siphalor.tweed5.core.api.container.ConfigContainer;
 import de.siphalor.tweed5.core.api.entry.ConfigEntry;
 import de.siphalor.tweed5.core.api.middleware.Middleware;
-import de.siphalor.tweed5.serde.extension.api.TweedEntryReadException;
 import de.siphalor.tweed5.serde.extension.api.TweedEntryReader;
 import de.siphalor.tweed5.serde.extension.api.extension.ReadWriteExtensionSetupContext;
 import de.siphalor.tweed5.serde.extension.api.extension.ReadWriteRelatedExtension;
@@ -11,6 +10,7 @@ import de.siphalor.tweed5.defaultextensions.pather.api.PatherExtension;
 import de.siphalor.tweed5.defaultextensions.presets.api.PresetsExtension;
 import de.siphalor.tweed5.defaultextensions.readfallback.api.ReadFallbackExtension;
 import de.siphalor.tweed5.defaultextensions.validation.api.ValidationExtension;
+import de.siphalor.tweed5.serde.extension.api.read.result.TweedReadResult;
 import lombok.extern.apachecommons.CommonsLog;
 import org.jspecify.annotations.NonNull;
 
@@ -30,8 +30,6 @@ public class ReadFallbackExtensionImpl implements ReadFallbackExtension, ReadWri
 		PresetsExtension presetsExtension = configContainer.extension(PresetsExtension.class)
 				.orElseThrow(() -> new IllegalStateException(getClass().getSimpleName()
 						+ " requires " + ReadFallbackExtension.class.getSimpleName()));
-		PatherExtension patherExtension = configContainer.extension(PatherExtension.class).orElse(null);
-
 		context.registerReaderMiddleware(new Middleware<TweedEntryReader<?, ?>>() {
 			@Override
 			public String id() {
@@ -53,23 +51,16 @@ public class ReadFallbackExtensionImpl implements ReadFallbackExtension, ReadWri
 				//noinspection unchecked
 				TweedEntryReader<Object, ConfigEntry<Object>> castedInner =
 						(TweedEntryReader<Object, @NonNull ConfigEntry<Object>>) inner;
-				return (TweedEntryReader<Object, @NonNull ConfigEntry<Object>>) (reader, entry, context) -> {
-					try {
-						return castedInner.read(reader, entry, context);
-					} catch (TweedEntryReadException e) {
-						if (patherExtension == null) {
-							log.error("Failed to read entry: " + e.getMessage(), e);
-						} else {
-							log.error(
-									"Failed to read entry: " + e.getMessage()
-											+ " at " + patherExtension.getPath(context),
-									e
+				return (TweedEntryReader<Object, @NonNull ConfigEntry<Object>>) (reader, entry, context) ->
+						castedInner.read(reader, entry, context).catchError(
+								issues -> {
+									Object fallback =
+											presetsExtension.presetValue(entry, PresetsExtension.DEFAULT_PRESET_NAME);
+									return TweedReadResult.withIssues(fallback, issues);
+								},
+								context
 						);
 			}
-						return presetsExtension.presetValue(entry, PresetsExtension.DEFAULT_PRESET_NAME);
-					}
-				};
-			}
 		});
 	}
 }

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

@@ -9,12 +9,6 @@ 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.core.api.middleware.MiddlewareContainer;
-import de.siphalor.tweed5.serde.extension.api.TweedEntryReadException;
-import de.siphalor.tweed5.serde.extension.api.TweedEntryReader;
-import de.siphalor.tweed5.serde.extension.api.TweedReadContext;
-import de.siphalor.tweed5.serde.extension.api.extension.ReadWriteExtensionSetupContext;
-import de.siphalor.tweed5.serde.extension.api.extension.ReadWriteRelatedExtension;
-import de.siphalor.tweed5.serde_api.api.TweedDataReader;
 import de.siphalor.tweed5.defaultextensions.comment.api.CommentModifyingExtension;
 import de.siphalor.tweed5.defaultextensions.comment.api.CommentProducer;
 import de.siphalor.tweed5.defaultextensions.pather.api.PathTracking;
@@ -30,6 +24,13 @@ import de.siphalor.tweed5.defaultextensions.validation.api.result.ValidationIssu
 import de.siphalor.tweed5.defaultextensions.validation.api.result.ValidationResult;
 import de.siphalor.tweed5.patchwork.api.Patchwork;
 import de.siphalor.tweed5.patchwork.api.PatchworkPartAccess;
+import de.siphalor.tweed5.serde.extension.api.TweedEntryReader;
+import de.siphalor.tweed5.serde.extension.api.TweedReadContext;
+import de.siphalor.tweed5.serde.extension.api.extension.ReadWriteExtensionSetupContext;
+import de.siphalor.tweed5.serde.extension.api.extension.ReadWriteRelatedExtension;
+import de.siphalor.tweed5.serde.extension.api.read.result.TweedReadIssue;
+import de.siphalor.tweed5.serde.extension.api.read.result.TweedReadResult;
+import de.siphalor.tweed5.serde_api.api.TweedDataReader;
 import lombok.*;
 import org.jspecify.annotations.Nullable;
 
@@ -233,8 +234,7 @@ public class ValidationExtensionImpl implements ReadWriteRelatedExtension, Valid
 			return (TweedDataReader reader, ConfigEntry<Object> entry, TweedReadContext context) -> {
 				ValidationIssues validationIssues = getOrCreateValidationIssues(context.extensionsData());
 
-				Object value = castedInner.read(reader, entry, context);
-
+				return castedInner.read(reader, entry, context).andThen(value -> {
 					ConfigEntryValidator entryValidator = entry.extensionsData()
 							.get(customEntryDataAccess)
 							.completeValidator();
@@ -242,26 +242,39 @@ public class ValidationExtensionImpl implements ReadWriteRelatedExtension, Valid
 
 					ValidationResult<Object> validationResult = entryValidator.validate(entry, value);
 
-				if (!validationResult.issues().isEmpty()) {
+					if (validationResult.issues().isEmpty()) {
+						return TweedReadResult.ok(validationResult.value());
+					}
+
 					String path = patherExtension.getPath(context);
 					validationIssues.issuesByPath().put(path, new ValidationIssues.EntryIssues(
 							entry,
 							validationResult.issues()
 					));
-				}
-
 					if (validationResult.hasError()) {
-					throw new TweedEntryReadException(
-							"Failed to validate entry: " + validationResult.issues(),
-							context
+						return TweedReadResult.failed(
+								mapValidationIssuesToReadIssues(validationResult.issues(), context)
+						);
+					} else {
+						return TweedReadResult.withIssues(
+								validationResult.value(),
+								mapValidationIssuesToReadIssues(validationResult.issues(), context)
 						);
 					}
-
-				return validationResult.value();
+				}, context);
 			};
 		}
 	}
 
+	private static TweedReadIssue[] mapValidationIssuesToReadIssues(
+			Collection<ValidationIssue> issues,
+			TweedReadContext context
+	) {
+		return issues.stream().map(
+				validationIssue -> TweedReadIssue.error(validationIssue.message(), context)
+		).toArray(TweedReadIssue[]::new);
+	}
+
 	private ValidationIssues getOrCreateValidationIssues(Patchwork readContextExtensionsData) {
 		assert readContextValidationIssuesAccess != null;
 		ValidationIssues validationIssues = readContextExtensionsData.get(readContextValidationIssuesAccess);

tweed5/default-extensions/src/test/java/de/siphalor/tweed5/defaultextensions/patch/impl/PatchExtensionImplTest.java

@@ -9,6 +9,7 @@ import de.siphalor.tweed5.core.impl.entry.NullableConfigEntryImpl;
 import de.siphalor.tweed5.core.impl.entry.SimpleConfigEntryImpl;
 import de.siphalor.tweed5.core.impl.entry.StaticMapCompoundConfigEntryImpl;
 import de.siphalor.tweed5.serde.extension.api.ReadWriteExtension;
+import de.siphalor.tweed5.serde.extension.api.read.result.TweedReadResult;
 import de.siphalor.tweed5.serde.hjson.HjsonLexer;
 import de.siphalor.tweed5.serde.hjson.HjsonReader;
 import de.siphalor.tweed5.defaultextensions.patch.api.PatchExtension;
@@ -150,7 +151,7 @@ class PatchExtensionImplTest {
 		PatchExtension patchExtension = configContainer.extension(PatchExtension.class).orElseThrow();
 
 		var patchInfo = new AtomicReference<@Nullable PatchInfo>();
-		Map<String, Object> patchValue = rootEntry.call(read(
+		TweedReadResult<Map<String, Object>> patchResult = rootEntry.call(read(
 				reader, extensionsData ->
 						patchInfo.set(patchExtension.collectPatchInfo(extensionsData))
 		));
@@ -158,7 +159,7 @@ class PatchExtensionImplTest {
 		Map<String, Object> resultValue = patchExtension.patch(
 				rootEntry,
 				baseValue,
-				patchValue,
+				patchResult.value(),
 				Objects.requireNonNull(patchInfo.get())
 		);
 

tweed5/default-extensions/src/test/java/de/siphalor/tweed5/defaultextensions/readfallback/impl/ReadFallbackExtensionImplTest.java

@@ -1,16 +1,19 @@
 package de.siphalor.tweed5.defaultextensions.readfallback.impl;
 
 import ch.qos.logback.classic.Level;
-import ch.qos.logback.classic.spi.ILoggingEvent;
 import de.siphalor.tweed5.core.api.entry.CompoundConfigEntry;
 import de.siphalor.tweed5.core.api.entry.ConfigEntry;
 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.pather.api.PatherExtension;
+import de.siphalor.tweed5.defaultextensions.presets.api.PresetsExtension;
+import de.siphalor.tweed5.defaultextensions.readfallback.api.ReadFallbackExtension;
 import de.siphalor.tweed5.serde.extension.api.ReadWriteExtension;
-import de.siphalor.tweed5.serde.extension.api.TweedEntryReadException;
 import de.siphalor.tweed5.serde.extension.api.TweedReadContext;
 import de.siphalor.tweed5.serde.extension.api.TweedWriteContext;
+import de.siphalor.tweed5.serde.extension.api.read.result.TweedReadIssue;
+import de.siphalor.tweed5.serde.extension.api.read.result.TweedReadResult;
 import de.siphalor.tweed5.serde.extension.api.readwrite.TweedEntryReaderWriter;
 import de.siphalor.tweed5.serde.extension.api.readwrite.TweedEntryReaderWriters;
 import de.siphalor.tweed5.serde.hjson.HjsonLexer;
@@ -19,9 +22,6 @@ import de.siphalor.tweed5.serde_api.api.TweedDataReadException;
 import de.siphalor.tweed5.serde_api.api.TweedDataReader;
 import de.siphalor.tweed5.serde_api.api.TweedDataVisitor;
 import de.siphalor.tweed5.serde_api.api.TweedDataWriteException;
-import de.siphalor.tweed5.defaultextensions.pather.api.PatherExtension;
-import de.siphalor.tweed5.defaultextensions.presets.api.PresetsExtension;
-import de.siphalor.tweed5.defaultextensions.readfallback.api.ReadFallbackExtension;
 import de.siphalor.tweed5.testutils.generic.log.LogCaptureMockitoExtension;
 import de.siphalor.tweed5.testutils.generic.log.LogsCaptor;
 import org.jspecify.annotations.NullMarked;
@@ -34,12 +34,11 @@ import java.util.Collections;
 import java.util.HashMap;
 import java.util.Map;
 
+import static de.siphalor.tweed5.defaultextensions.presets.api.PresetsExtension.presetValue;
 import static de.siphalor.tweed5.serde.extension.api.ReadWriteExtension.entryReaderWriter;
 import static de.siphalor.tweed5.serde.extension.api.ReadWriteExtension.read;
 import static de.siphalor.tweed5.serde.extension.api.readwrite.TweedEntryReaderWriters.compoundReaderWriter;
-import static de.siphalor.tweed5.defaultextensions.presets.api.PresetsExtension.presetValue;
 import static org.assertj.core.api.Assertions.assertThat;
-import static org.assertj.core.api.InstanceOfAssertFactories.STRING;
 
 @ExtendWith(LogCaptureMockitoExtension.class)
 @NullMarked
@@ -59,12 +58,18 @@ class ReadFallbackExtensionImplTest {
 		configContainer.attachTree(entry);
 		configContainer.initialize();
 
-		assertThat(entry.call(read(new HjsonReader(new HjsonLexer(new StringReader("12")))))).isEqualTo(12);
+		assertThat(entry.call(read(new HjsonReader(new HjsonLexer(new StringReader("12"))))))
+				.isEqualTo(TweedReadResult.ok(12));
 		assertThat(logsCaptor.getLogsForLevel(Level.ERROR)).isEmpty();
 		logsCaptor.clear();
 
-		assertThat(entry.call(read(new HjsonReader(new HjsonLexer(new StringReader("13")))))).isEqualTo(-1);
-		assertThat(logsCaptor.getLogsForLevel(Level.ERROR)).hasSize(1);
+		assertThat(entry.call(read(new HjsonReader(new HjsonLexer(new StringReader("13")))))).satisfies(
+				r -> assertThat(r).extracting(TweedReadResult::value).isEqualTo(-1),
+				r -> assertThat(r.issues()).singleElement()
+						.extracting(TweedReadIssue::exception)
+						.extracting(Throwable::getMessage)
+						.isEqualTo("Value is not even")
+				);
 	}
 
 	@SuppressWarnings({"unchecked", "rawtypes"})
@@ -105,6 +110,7 @@ class ReadFallbackExtensionImplTest {
 		assertThat(root.call(read(new HjsonReader(new HjsonLexer(new StringReader(
 				"{first: {second: 12}}"
 		))))))
+				.extracting(TweedReadResult::value)
 				.extracting(map -> (Map<String, Object>) map.get("first"))
 				.extracting(map -> (Integer) map.get("second"))
 				.isEqualTo(12);
@@ -114,22 +120,20 @@ class ReadFallbackExtensionImplTest {
 		assertThat(root.call(read(new HjsonReader(new HjsonLexer(new StringReader(
 				"{first: {second: 13}}"
 		))))))
+				.extracting(TweedReadResult::value)
 				.extracting(map -> (Map<String, Object>) map.get("first"))
 				.extracting(map -> (Integer) map.get("second"))
 				.isEqualTo(-1);
-		assertThat(logsCaptor.getLogsForLevel(Level.ERROR)).singleElement()
-				.extracting(ILoggingEvent::getMessage)
-				.asInstanceOf(STRING)
-				.contains("first.second");
+		assertThat(logsCaptor.getLogsForLevel(Level.ERROR)).isEmpty();
 	}
 
 	private static class EvenIntReader implements TweedEntryReaderWriter<Integer, ConfigEntry<Integer>> {
 		@Override
-		public Integer read(
+		public TweedReadResult<Integer> read(
 				TweedDataReader reader,
 				ConfigEntry<Integer> entry,
 				TweedReadContext context
-		) throws TweedEntryReadException {
+		) {
 			int value;
 			try {
 				value = reader.readToken().readAsInt();
@@ -137,9 +141,9 @@ class ReadFallbackExtensionImplTest {
 				throw new IllegalStateException("Should not be called", e);
 			}
 			if (value % 2 == 0) {
-				return value;
+				return TweedReadResult.ok(value);
 			} else {
-				throw new TweedEntryReadException("Value is not even", context);
+				return TweedReadResult.error(TweedReadIssue.error("Value is not even", context));
 			}
 		}
 

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

@@ -7,6 +7,7 @@ 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.serde.extension.api.ReadWriteExtension;
+import de.siphalor.tweed5.serde.extension.api.read.result.TweedReadResult;
 import de.siphalor.tweed5.serde.hjson.HjsonCommentType;
 import de.siphalor.tweed5.serde.hjson.HjsonLexer;
 import de.siphalor.tweed5.serde.hjson.HjsonReader;
@@ -156,12 +157,14 @@ class ValidationExtensionImplTest {
 				}
 				""")));
 		var validationIssues = new AtomicReference<@Nullable ValidationIssues>();
-		Map<String, Object> value = configContainer.rootEntry().call(read(
+		TweedReadResult<Map<String, Object>> value = configContainer.rootEntry().call(read(
 				reader,
 				extensionsData -> validationIssues.set(validationExtension.captureValidationIssues(extensionsData))
 		));
 
-		assertThat(value).isEqualTo(Map.of("byte", (byte) 11, "int", 123, "double", 0.5));
+		assertThat(value)
+				.extracting(TweedReadResult::value)
+				.isEqualTo(Map.of("byte", (byte) 11, "int", 123, "double", 0.5));
 		//noinspection DataFlowIssue
 		assertThat(validationIssues.get()).isNotNull().satisfies(
 				vi -> assertValidationIssue(

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

@@ -5,6 +5,7 @@ import de.siphalor.tweed5.core.api.entry.SimpleConfigEntry;
 import de.siphalor.tweed5.core.impl.DefaultConfigContainer;
 import de.siphalor.tweed5.core.impl.entry.SimpleConfigEntryImpl;
 import de.siphalor.tweed5.serde.extension.api.ReadWriteExtension;
+import de.siphalor.tweed5.serde.extension.api.read.result.TweedReadResult;
 import de.siphalor.tweed5.serde.hjson.HjsonCommentType;
 import de.siphalor.tweed5.serde.hjson.HjsonLexer;
 import de.siphalor.tweed5.serde.hjson.HjsonReader;
@@ -30,6 +31,7 @@ import static de.siphalor.tweed5.defaultextensions.presets.api.PresetsExtension.
 import static de.siphalor.tweed5.defaultextensions.validation.api.ValidationExtension.validators;
 import static de.siphalor.tweed5.serde.extension.api.ReadWriteExtension.*;
 import static de.siphalor.tweed5.serde.extension.api.readwrite.TweedEntryReaderWriters.*;
+import static org.assertj.core.api.Assertions.assertThat;
 import static org.junit.jupiter.api.Assertions.assertEquals;
 
 class ValidationFallbackExtensionImplTest {
@@ -114,8 +116,9 @@ class ValidationFallbackExtensionImplTest {
 	@ParameterizedTest
 	@ValueSource(strings = {"0", "7", "123", "null"})
 	void fallbackTriggers(String input) {
-		Integer result = intEntry.call(read(new HjsonReader(new HjsonLexer(new StringReader(input)))));
-		assertEquals(3, result);
+		TweedReadResult<Integer> result = intEntry.call(read(new HjsonReader(new HjsonLexer(new StringReader(input)))));
+		assertThat(result).extracting(TweedReadResult::value).isEqualTo(3);
+		assertThat(result.issues()).hasSize(1);
 	}
 
 	@Test

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

@@ -2,6 +2,7 @@ package de.siphalor.tweed5.serde.extension.api;
 
 import de.siphalor.tweed5.core.api.entry.ConfigEntry;
 import de.siphalor.tweed5.core.api.extension.TweedExtension;
+import de.siphalor.tweed5.serde.extension.api.read.result.TweedReadResult;
 import de.siphalor.tweed5.serde.extension.api.readwrite.TweedEntryReaderWriter;
 import de.siphalor.tweed5.serde.extension.impl.ReadWriteExtensionImpl;
 import de.siphalor.tweed5.serde_api.api.TweedDataReader;
@@ -55,11 +56,11 @@ public interface ReadWriteExtension extends TweedExtension {
 		};
 	}
 
-	static <T extends @Nullable Object> Function<ConfigEntry<T>, T> read(TweedDataReader reader) {
+	static <T extends @Nullable Object> Function<ConfigEntry<T>, TweedReadResult<T>> read(TweedDataReader reader) {
 		return read(reader, null);
 	}
 
-	static <T extends @Nullable Object> Function<ConfigEntry<T>, T> read(
+	static <T extends @Nullable Object> Function<ConfigEntry<T>, TweedReadResult<T>> read(
 			TweedDataReader reader,
 			@Nullable Consumer<Patchwork> contextExtensionsDataCustomizer
 	) {
@@ -115,7 +116,7 @@ public interface ReadWriteExtension extends TweedExtension {
 
 	Patchwork createReadWriteContextExtensionsData();
 
-	<T extends @Nullable Object> T read(TweedDataReader reader, ConfigEntry<T> entry, Patchwork contextExtensionsData)
+	<T extends @Nullable Object> TweedReadResult<T> read(TweedDataReader reader, ConfigEntry<T> entry, Patchwork contextExtensionsData)
 			throws TweedEntryReadException;
 
 	<T extends @Nullable Object> void write(

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

@@ -1,10 +1,11 @@
 package de.siphalor.tweed5.serde.extension.api;
 
 import de.siphalor.tweed5.core.api.entry.ConfigEntry;
+import de.siphalor.tweed5.serde.extension.api.read.result.TweedReadResult;
 import de.siphalor.tweed5.serde_api.api.TweedDataReader;
 import org.jspecify.annotations.Nullable;
 
 @FunctionalInterface
 public interface TweedEntryReader<T extends @Nullable Object, C extends ConfigEntry<T>> {
-	T read(TweedDataReader reader, C entry, TweedReadContext context) throws TweedEntryReadException;
+	TweedReadResult<T> read(TweedDataReader reader, C entry, TweedReadContext context);
 }

tweed5/serde-extension/src/main/java/de/siphalor/tweed5/serde/extension/api/read/result/ThrowingFunction.java

@@ -0,0 +1,7 @@
+package de.siphalor.tweed5.serde.extension.api.read.result;
+
+import org.jspecify.annotations.Nullable;
+
+public interface ThrowingFunction<T extends @Nullable Object, R extends @Nullable Object> {
+	R apply(T value) throws Exception;
+}

tweed5/serde-extension/src/main/java/de/siphalor/tweed5/serde/extension/api/read/result/ThrowingReadFunction.java

@@ -0,0 +1,71 @@
+package de.siphalor.tweed5.serde.extension.api.read.result;
+
+import de.siphalor.tweed5.serde.extension.api.TweedReadContext;
+import org.jspecify.annotations.Nullable;
+
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.List;
+
+@FunctionalInterface
+public interface ThrowingReadFunction<T extends @Nullable Object, R extends @Nullable Object> {
+	static <T extends @Nullable Object, R extends @Nullable Object> ThrowingReadFunction<T, R> any(
+			TweedReadContext readContext,
+			ThrowingFunction<T, R>... functions
+	) {
+		//noinspection unchecked
+		ThrowingReadFunction<T, R>[] wrappedFunctions = new ThrowingReadFunction[functions.length];
+		for (int i = 0; i < functions.length; i++) {
+			wrappedFunctions[i] = wrap(readContext, functions[i]);
+		}
+		return any(wrappedFunctions);
+	}
+
+	static <T extends @Nullable Object, R extends @Nullable Object> ThrowingReadFunction<T, R> any(
+			ThrowingReadFunction<T, R>... functions
+	) {
+		if (functions.length == 0) {
+			throw new IllegalArgumentException("At least one function is required");
+		}
+		return value -> {
+			List<TweedReadIssue> issues = null;
+			boolean foundEmpty = false;
+			for (ThrowingReadFunction<T, R> function : functions) {
+				TweedReadResult<R> result = function.apply(value);
+				if (result.hasValue()) {
+					return result;
+				} else if (!result.isFailed()) {
+					foundEmpty = true;
+				}
+				if (result.hasIssues()) {
+					if (issues == null) {
+						issues = new ArrayList<>(functions.length);
+						issues.addAll(Arrays.asList(result.issues()));
+					}
+				}
+			}
+			if (foundEmpty) {
+				return TweedReadResult.empty();
+			}
+			if (issues != null) {
+				return TweedReadResult.failed(issues.toArray(new TweedReadIssue[0]));
+			}
+			throw new IllegalStateException("Unreachable");
+		};
+	}
+
+	static <T extends @Nullable Object, R extends @Nullable Object> ThrowingReadFunction<T, R> wrap(
+			TweedReadContext readContext,
+			ThrowingFunction<T, R> function
+	) {
+		return value -> {
+			try {
+				return TweedReadResult.ok(function.apply(value));
+			} catch (Exception e) {
+				return TweedReadResult.failed(TweedReadIssue.error(e, readContext));
+			}
+		};
+	}
+
+	TweedReadResult<R> apply(T value) throws Exception;
+}

tweed5/serde-extension/src/main/java/de/siphalor/tweed5/serde/extension/api/read/result/TweedReadIssue.java

@@ -0,0 +1,26 @@
+package de.siphalor.tweed5.serde.extension.api.read.result;
+
+
+import de.siphalor.tweed5.serde.extension.api.TweedReadContext;
+import lombok.*;
+
+@RequiredArgsConstructor(access = AccessLevel.PRIVATE)
+@EqualsAndHashCode
+public class TweedReadIssue {
+	@Getter
+	private final Exception exception;
+	private final TweedReadContext readContext;
+
+	public static TweedReadIssue error(String message, TweedReadContext readContext) {
+		return new TweedReadIssue(new Exception(message), readContext);
+	}
+
+	public static TweedReadIssue error(Exception exception, TweedReadContext readContext) {
+		return new TweedReadIssue(exception, readContext);
+	}
+
+	@Override
+	public String toString() {
+		return "TweedReadIssue(" + exception + ")";
+	}
+}

tweed5/serde-extension/src/main/java/de/siphalor/tweed5/serde/extension/api/read/result/TweedReadResult.java

@@ -0,0 +1,168 @@
+package de.siphalor.tweed5.serde.extension.api.read.result;
+
+import de.siphalor.tweed5.serde.extension.api.TweedReadContext;
+import lombok.AccessLevel;
+import lombok.EqualsAndHashCode;
+import lombok.RequiredArgsConstructor;
+import org.jspecify.annotations.Nullable;
+
+import java.util.Arrays;
+
+@RequiredArgsConstructor(access = AccessLevel.PRIVATE)
+@EqualsAndHashCode(doNotUseGetters = true)
+public class TweedReadResult<T extends @Nullable Object> {
+	private static final TweedReadResult<?> EMPTY = new TweedReadResult<>(null, false, null, Severity.OK);
+
+	private final T value;
+	private final boolean hasValue;
+	private final TweedReadIssue @Nullable [] issues;
+	private final Severity severity;
+
+	public static <T extends @Nullable Object> TweedReadResult<T> ok(T value) {
+		return new TweedReadResult<>(value, true, null, Severity.OK);
+	}
+
+	public static <T extends @Nullable Object> TweedReadResult<T> empty() {
+		//noinspection unchecked
+		return (TweedReadResult<T>) EMPTY;
+	}
+
+	public static <T extends @Nullable Object> TweedReadResult<T> withIssues(T value, TweedReadIssue... issues) {
+		return new TweedReadResult<>(value, true, issues, Severity.OK);
+	}
+
+	public static <T extends @Nullable Object> TweedReadResult<T> error(TweedReadIssue... issues) {
+		return new TweedReadResult<>(null, false, issues, Severity.ERROR);
+	}
+
+	public static <T extends @Nullable Object> TweedReadResult<T> failed(TweedReadIssue... issues) {
+		if (issues.length == 0) {
+			throw new IllegalArgumentException("At least one issue is required for a failed read result");
+		}
+		return new TweedReadResult<>(null, false, issues, Severity.FAILURE);
+	}
+
+	public T value() {
+		if (hasValue) {
+			return value;
+		}
+		throw new IllegalStateException("No value present");
+	}
+
+	public boolean hasValue() {
+		return hasValue;
+	}
+
+	public boolean hasIssues() {
+		return issues != null;
+	}
+
+	public TweedReadIssue [] issues() {
+		if (issues == null) {
+			return new TweedReadIssue[0];
+		}
+		return issues;
+	}
+
+	public boolean isError() {
+		return severity == Severity.ERROR;
+	}
+
+	public boolean isFailed() {
+		return severity == Severity.FAILURE;
+	}
+
+	public <R extends @Nullable Object> TweedReadResult<R> map(
+			ThrowingFunction<T, R> function,
+			TweedReadContext readContext
+	) {
+		return andThen(value -> ok(function.apply(value)), readContext);
+	}
+
+	public <R extends @Nullable Object> TweedReadResult<R> andThen(
+			ThrowingReadFunction<T, R> function,
+			TweedReadContext readContext
+	) {
+		if (severity != Severity.OK || !hasValue()) {
+			//noinspection unchecked
+			return (TweedReadResult<R>) this;
+		}
+		try {
+			TweedReadResult<R> innerResult = function.apply(value());
+			TweedReadIssue[] issues = combineIssues(issues(), innerResult.issues());
+			if (issues.length == 0) {
+				return innerResult;
+			}
+			if (innerResult.isFailed()) {
+				return failed(issues);
+			} else if (innerResult.isError()) {
+				return error(issues);
+			} else if (innerResult.hasValue()) {
+				return withIssues(innerResult.value(), issues);
+			} else {
+				return empty();
+			}
+		} catch (Exception exception) {
+			if (hasIssues()) {
+				TweedReadIssue[] issues = new TweedReadIssue[issues().length + 1];
+				System.arraycopy(issues(), 0, issues, 0, issues().length);
+				issues[issues().length] = TweedReadIssue.error(exception, readContext);
+				return failed(issues);
+			}
+			return failed(TweedReadIssue.error(exception, readContext));
+		}
+	}
+
+	public TweedReadResult<T> catchError(
+			ThrowingFunction<TweedReadIssue[], TweedReadResult<T>> errorHandler,
+			TweedReadContext readContext
+	) {
+		if (severity != Severity.ERROR) {
+			return this;
+		}
+		try {
+			return errorHandler.apply(issues());
+		} catch (Exception exception) {
+			TweedReadIssue[] issues = new TweedReadIssue[issues().length + 1];
+			System.arraycopy(issues(), 0, issues, 0, issues().length);
+			issues[issues().length] = TweedReadIssue.error(exception, readContext);
+			return error(issues);
+		}
+	}
+
+	private static TweedReadIssue[] combineIssues(TweedReadIssue[] a, TweedReadIssue[] b) {
+		if (a.length == 0) {
+			return b;
+		}
+		if (b.length == 0) {
+			return a;
+		}
+		TweedReadIssue[] result = new TweedReadIssue[a.length + b.length];
+		System.arraycopy(a, 0, result, 0, a.length);
+		System.arraycopy(b, 0, result, a.length, b.length);
+		return result;
+	}
+
+	@Override
+	public String toString() {
+		if (severity == Severity.FAILURE) {
+			return "TweedReadResult#failed(issues=" + Arrays.toString(issues) + ')';
+		} else if (severity == Severity.ERROR) {
+			return "TweedReadResult#error(issues=" + Arrays.toString(issues) + ')';
+		} else if (hasValue) {
+			if (hasIssues()) {
+				return "TweedReadResult#withIssues(value=" + value + ", issues=" + Arrays.toString(issues) + ')';
+			} else {
+				return "TweedReadResult#ok(value=" + value + ')';
+			}
+		} else {
+			return "TweedReadResult#empty";
+		}
+	}
+
+	private enum Severity {
+		OK,
+		ERROR,
+		FAILURE,
+	}
+}

tweed5/serde-extension/src/main/java/de/siphalor/tweed5/serde/extension/api/read/result/package-info.java

@@ -0,0 +1,4 @@
+@NullMarked
+package de.siphalor.tweed5.serde.extension.api.read.result;
+
+import org.jspecify.annotations.NullMarked;

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

@@ -9,6 +9,7 @@ import de.siphalor.tweed5.core.api.middleware.Middleware;
 import de.siphalor.tweed5.serde.extension.api.*;
 import de.siphalor.tweed5.serde.extension.api.extension.ReadWriteExtensionSetupContext;
 import de.siphalor.tweed5.serde.extension.api.extension.ReadWriteRelatedExtension;
+import de.siphalor.tweed5.serde.extension.api.read.result.TweedReadResult;
 import de.siphalor.tweed5.serde_api.api.TweedDataReader;
 import de.siphalor.tweed5.serde_api.api.TweedDataVisitor;
 import de.siphalor.tweed5.serde_api.api.TweedDataWriteException;
@@ -136,7 +137,7 @@ public class ReadWriteExtensionImpl implements ReadWriteExtension {
 		return readWriteContextPatchworkFactory.create();
 	}
 
-	public <T extends @Nullable Object> T read(
+	public <T extends @Nullable Object> TweedReadResult<T> read(
 			TweedDataReader reader,
 			ConfigEntry<T> entry,
 			Patchwork contextExtensionsData

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

@@ -5,6 +5,9 @@ import de.siphalor.tweed5.core.api.entry.CompoundConfigEntry;
 import de.siphalor.tweed5.core.api.entry.ConfigEntry;
 import de.siphalor.tweed5.core.api.entry.NullableConfigEntry;
 import de.siphalor.tweed5.serde.extension.api.*;
+import de.siphalor.tweed5.serde.extension.api.read.result.ThrowingReadFunction;
+import de.siphalor.tweed5.serde.extension.api.read.result.TweedReadIssue;
+import de.siphalor.tweed5.serde.extension.api.read.result.TweedReadResult;
 import de.siphalor.tweed5.serde.extension.api.readwrite.TweedEntryReaderWriter;
 import de.siphalor.tweed5.serde_api.api.*;
 import lombok.AccessLevel;
@@ -38,15 +41,14 @@ public class TweedEntryReaderWriterImpls {
 
 	public static class NullableReaderWriter<T extends @Nullable Object> implements TweedEntryReaderWriter<T, NullableConfigEntry<T>> {
 		@Override
-		public T read(TweedDataReader reader, NullableConfigEntry<T> entry, TweedReadContext context)
-				throws TweedEntryReadException {
+		public TweedReadResult<T> read(TweedDataReader reader, NullableConfigEntry<T> entry, TweedReadContext context) {
 			try {
 				if (reader.peekToken().isNull()) {
 					reader.readToken();
-					return null;
+					return TweedReadResult.ok(null);
 				}
 			} catch (TweedDataReadException e) {
-				throw new TweedEntryReadException(e, context);
+				return TweedReadResult.failed(TweedReadIssue.error(e, context));
 			}
 
 			TweedEntryReader<T, ConfigEntry<T>> nonNullReader = context.readWriteExtension().getReaderChain(entry.nonNullEntry());
@@ -75,14 +77,14 @@ public class TweedEntryReaderWriterImpls {
 		private final TweedEntryReader<T, C> delegate;
 
 		@Override
-		public T read(TweedDataReader reader, C entry, TweedReadContext context) throws TweedEntryReadException {
+		public TweedReadResult<T> read(TweedDataReader reader, C entry, TweedReadContext context) {
 			try {
 				if (reader.peekToken().isNull()) {
 					reader.readToken();
-					return null;
+					return TweedReadResult.ok(null);
 				}
 			} catch (TweedDataReadException e) {
-				throw new TweedEntryReadException(e, context);
+				return TweedReadResult.failed(TweedReadIssue.error(e, context));
 			}
 			return delegate.read(reader, entry, context);
 		}
@@ -109,12 +111,11 @@ public class TweedEntryReaderWriterImpls {
 		private final PrimitiveWriteFunction<T> writerFunction;
 
 		@Override
-		public T read(TweedDataReader reader, ConfigEntry<T> entry, TweedReadContext context)
-				throws TweedEntryReadException {
+		public TweedReadResult<T> read(TweedDataReader reader, ConfigEntry<T> entry, TweedReadContext context) {
 			try {
-				return readerFunction.read(reader.readToken());
+				return TweedReadResult.ok(readerFunction.read(reader.readToken()));
 			} catch (TweedDataReadException e) {
-				throw new TweedEntryReadException(e, context);
+				return TweedReadResult.failed(TweedReadIssue.error(e, context));
 			}
 		}
 
@@ -128,20 +129,15 @@ public class TweedEntryReaderWriterImpls {
 	@RequiredArgsConstructor
 	public static class EnumReaderWriter<T extends Enum<?>> implements TweedEntryReaderWriter<T, ConfigEntry<T>> {
 		@Override
-		public T read(TweedDataReader reader, ConfigEntry<T> entry, TweedReadContext context) throws
-				TweedEntryReadException {
-			try {
-				TweedDataToken token = reader.readToken();
-				assertIsToken(token, TweedDataToken::canReadAsString, "Expected string", context);
+		public TweedReadResult<T> read(TweedDataReader reader, ConfigEntry<T> entry, TweedReadContext context) {
 			//noinspection unchecked,rawtypes
-				return (T) Enum.valueOf(((Class) entry.valueClass()), token.readAsString());
-			} catch (TweedDataReadException | IllegalArgumentException e) {
-				throw new TweedEntryReadException(
-						"Failed reading enum value for " + entry.valueClass().getName(),
-						e,
-						context
-				);
-			}
+			return requireToken(reader, TweedDataToken::canReadAsString, "Expected string", context)
+					.map(TweedDataToken::readAsString, context)
+					.andThen(ThrowingReadFunction.any(
+							context,
+							value -> (T) Enum.valueOf(((Class) entry.valueClass()), value),
+							value -> (T) Enum.valueOf(((Class) entry.valueClass()), value.toUpperCase(Locale.ROOT))
+					), context);
 		}
 
 		@Override
@@ -158,49 +154,46 @@ public class TweedEntryReaderWriterImpls {
 
 	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 {
-			TweedDataToken token;
-			try {
-				assertIsToken(reader.readToken(), TweedDataToken::isListStart, "Expected list start", context);
-				token = reader.peekToken();
-			} catch (TweedDataReadException e) {
-				throw new TweedEntryReadException("Failed reading collection start", e, context);
-			}
-			if (token.isListEnd()) {
-				return entry.instantiateCollection(0);
+		public TweedReadResult<C> read(TweedDataReader reader, CollectionConfigEntry<T, C> entry, TweedReadContext context) {
+			return requireToken(reader, TweedDataToken::isListStart, "Expected list start", context).andThen(_token -> {
+				if (reader.peekToken().isListEnd()) {
+					return TweedReadResult.ok(entry.instantiateCollection(0));
 				}
 
 				ConfigEntry<T> elementEntry = entry.elementEntry();
 				TweedEntryReader<T, ConfigEntry<T>> elementReader = context.readWriteExtension().getReaderChain(elementEntry);
 
-			List<@Nullable T> list = new ArrayList<>(20);
+				List<T> list = new ArrayList<>(20);
+				List<TweedReadIssue> issues = new ArrayList<>();
 				while (true) {
 					try {
-					token = reader.peekToken();
+						TweedDataToken token = reader.peekToken();
 						if (token.isListEnd()) {
 							reader.readToken();
 							break;
 						} else if (token.isListValue()) {
-						list.add(elementReader.read(reader, elementEntry, context));
+							TweedReadResult<T> elementResult = elementReader.read(reader, elementEntry, context);
+							issues.addAll(Arrays.asList(elementResult.issues()));
+							if (elementResult.isFailed() || elementResult.isError()) {
+								return TweedReadResult.failed(issues.toArray(new TweedReadIssue[0]));
+							} else if (elementResult.hasValue()) {
+								list.add(elementResult.value());
+							}
 						} else {
-						throw new TweedEntryReadException(
+							issues.add(TweedReadIssue.error(
 									"Unexpected token " + token + ": expected next list value or list end",
 									context
-						);
+							));
+							return TweedReadResult.failed(issues.toArray(new TweedReadIssue[0]));
 						}
 					} catch (TweedDataReadException e) {
-					throw new TweedEntryReadException(
-							"Failed reading element " + list.size() + " of collection",
-							e,
-							context
-					);
+						issues.add(TweedReadIssue.error(e, context));
 					}
 				}
-
 				C result = entry.instantiateCollection(list.size());
 				result.addAll(list);
-			return result;
+				return TweedReadResult.ok(result);
+			}, context);
 		}
 
 		@Override
@@ -226,16 +219,11 @@ public class TweedEntryReaderWriterImpls {
 
 	public static class CompoundReaderWriter<T> implements TweedEntryReaderWriter<T, CompoundConfigEntry<T>> {
 		@Override
-		public T read(TweedDataReader reader, CompoundConfigEntry<T> entry, TweedReadContext context) throws
-				TweedEntryReadException {
-			try {
-				assertIsToken(reader.readToken(), TweedDataToken::isMapStart, "Expected map start", context);
-			} catch (TweedDataReadException e) {
-				throw new TweedEntryReadException("Failed reading compound start", e, context);
-			}
-
+		public TweedReadResult<T> read(TweedDataReader reader, CompoundConfigEntry<T> entry, TweedReadContext context) {
+			return requireToken(reader, TweedDataToken::isMapStart, "Expected map start", context).andThen(_token -> {
 				Map<String, ConfigEntry<?>> compoundEntries = entry.subEntries();
 				T compoundValue = entry.instantiateValue();
+				List<TweedReadIssue> issues = new ArrayList<>();
 				while (true) {
 					try {
 						TweedDataToken token = reader.readToken();
@@ -247,24 +235,38 @@ public class TweedEntryReaderWriterImpls {
 							//noinspection unchecked
 							ConfigEntry<Object> subEntry = (ConfigEntry<Object>) compoundEntries.get(key);
 							if (subEntry == null) {
-							//noinspection DataFlowIssue
-							NOOP_READER_WRITER.read(reader, null, context);
+								TweedReadResult<Object> noopResult = NOOP_READER_WRITER.read(reader, null, context);
+								issues.addAll(Arrays.asList(noopResult.issues()));
+								if (noopResult.isFailed()) {
+									return TweedReadResult.failed(issues.toArray(new TweedReadIssue[0]));
+								}
 								continue;
 							}
 							val subEntryReaderChain = context.readWriteExtension().getReaderChain(subEntry);
-						Object subEntryValue = subEntryReaderChain.read(reader, subEntry, context);
-						entry.set(compoundValue, key, subEntryValue);
+							TweedReadResult<Object> subEntryResult = subEntryReaderChain.read(reader, subEntry, context);
+							issues.addAll(Arrays.asList(subEntryResult.issues()));
+							if (subEntryResult.isFailed() || subEntryResult.isError()) {
+								return TweedReadResult.failed(issues.toArray(new TweedReadIssue[0]));
+							} else if (subEntryResult.hasValue()) {
+								entry.set(compoundValue, key, subEntryResult.value());
+							}
 						} else {
-						throw new TweedEntryReadException(
+							issues.add(TweedReadIssue.error(
 									"Unexpected token " + token + ": Expected map key or map end",
 									context
-						);
+							));
+							return TweedReadResult.failed(issues.toArray(new TweedReadIssue[0]));
 						}
 					} catch (TweedDataReadException e) {
 						throw new TweedEntryReadException("Failed reading compound entry", e, context);
 					}
 				}
-			return compoundValue;
+				if (issues.isEmpty()) {
+					return TweedReadResult.ok(compoundValue);
+				} else {
+					return TweedReadResult.withIssues(compoundValue, issues.toArray(new TweedReadIssue[0]));
+				}
+			}, context);
 		}
 
 		@Override
@@ -291,12 +293,11 @@ public class TweedEntryReaderWriterImpls {
 
 	public static class NoopReaderWriter implements TweedEntryReaderWriter<@Nullable Object, ConfigEntry<Object>> {
 		@Override
-		public @Nullable Object read(TweedDataReader reader, ConfigEntry<Object> entry, TweedReadContext context)
-				throws TweedEntryReadException {
+		public TweedReadResult<@Nullable Object> read(TweedDataReader reader, ConfigEntry<Object> entry, TweedReadContext context) {
 			try {
 				TweedDataToken token = reader.readToken();
 				if (!token.isListStart() && !token.isMapStart()) {
-					return null;
+					return TweedReadResult.empty();
 				}
 
 				ArrayDeque<Context> stack = new ArrayDeque<>(20);
@@ -316,11 +317,11 @@ public class TweedEntryReaderWriterImpls {
 						stack.pop();
 					}
 					if (stack.isEmpty()) {
-						return null;
+						return TweedReadResult.empty();
 					}
 				}
 			} catch (TweedDataReadException e) {
-				throw new TweedEntryReadException("Failed skipping through value", e, context);
+				return TweedReadResult.failed(TweedReadIssue.error(e, context));
 			}
 		}
 
@@ -352,14 +353,23 @@ public class TweedEntryReaderWriterImpls {
 		}
 	}
 
-	private static void assertIsToken(
-			TweedDataToken token,
+	private static TweedReadResult<TweedDataToken> requireToken(
+			TweedDataReader reader,
 			Predicate<TweedDataToken> isToken,
 			String description,
 			TweedReadContext context
-	) throws TweedEntryReadException {
-		if (!isToken.test(token)) {
-			throw new TweedEntryReadException("Unexpected token " + token + ": " + description, context);
+	) {
+		try {
+			TweedDataToken token = reader.readToken();
+			if (isToken.test(token)) {
+				return TweedReadResult.ok(token);
+			}
+			return TweedReadResult.failed(TweedReadIssue.error(
+					"Unexpected token " + token + ": " + description,
+					context
+			));
+		} catch (TweedDataReadException e) {
+			return TweedReadResult.failed(TweedReadIssue.error(e, context));
 		}
 	}
 }

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

@@ -28,7 +28,6 @@ import static de.siphalor.tweed5.testutils.generic.MapTestUtils.sequencedMap;
 import static java.util.Map.entry;
 import static org.assertj.core.api.Assertions.assertThat;
 import static org.junit.jupiter.api.Assertions.assertDoesNotThrow;
-import static org.junit.jupiter.api.Assertions.assertEquals;
 
 class ReadWriteExtensionImplTest {
 	private final StringWriter stringWriter = new StringWriter();
@@ -97,7 +96,7 @@ class ReadWriteExtensionImplTest {
 	@Test
 	void read() {
 		ReadWriteExtension readWriteExtension = configContainer.extension(ReadWriteExtension.class).orElseThrow();
-		Map<String, Object> result = assertDoesNotThrow(() -> readWriteExtension.read(
+		var result = assertDoesNotThrow(() -> readWriteExtension.read(
 				new HjsonReader(new HjsonLexer(new StringReader("""
 						{
 						\tint: 123
@@ -112,9 +111,12 @@ class ReadWriteExtensionImplTest {
 				readWriteExtension.createReadWriteContextExtensionsData()
 		));
 
-		assertEquals(2, result.size());
-		assertEquals(123, result.get("int"));
-		assertEquals(Arrays.asList(true, false, true), result.get("list"));
+		assertThat(result.isFailed()).isFalse();
+		assertThat(result.hasValue()).isTrue();
+		assertThat(result.value()).isEqualTo(Map.of(
+				"int", 123,
+				"list", Arrays.asList(true, false, true)
+		));
 	}
 
 	private TweedDataVisitor setupWriter(Function<Writer, TweedDataVisitor> writerFactory) {

tweed5/weaver-pojo-serde-extension/src/test/java/de/siphalor/tweed5/weaver/pojoext/serde/api/ReadWritePojoWeavingProcessorTest.java

@@ -7,6 +7,7 @@ import de.siphalor.tweed5.serde.extension.api.ReadWriteExtension;
 import de.siphalor.tweed5.serde.extension.api.TweedEntryWriter;
 import de.siphalor.tweed5.serde.extension.api.TweedReaderWriterProvider;
 import de.siphalor.tweed5.serde.extension.api.TweedWriteContext;
+import de.siphalor.tweed5.serde.extension.api.read.result.TweedReadResult;
 import de.siphalor.tweed5.serde.hjson.HjsonLexer;
 import de.siphalor.tweed5.serde.hjson.HjsonReader;
 import de.siphalor.tweed5.serde.hjson.HjsonWriter;
@@ -55,7 +56,7 @@ class ReadWritePojoWeavingProcessorTest {
 						}"""
 		)));
 		assertThat(configContainer.rootEntry().call(read(reader)))
-				.isEqualTo(new AnnotatedConfig(987, "abdef", new TestClass(29)));
+				.isEqualTo(TweedReadResult.ok(new AnnotatedConfig(987, "abdef", new TestClass(29))));
 	}
 
 	@AutoService(TweedReaderWriterProvider.class)