diff --git a/build-logic/build.gradle.kts b/build-logic/build.gradle.kts
index 2e6a58c..8da6c23 100644
--- a/build-logic/build.gradle.kts
+++ b/build-logic/build.gradle.kts
@@ -7,6 +7,7 @@ configure<JavaPluginExtension> {
 }
 
 dependencies {
+    implementation(libs.crankcase.checkstyle)
     implementation(libs.crankcase.java)
     implementation(libs.crankcase.javaLibrary)
 }
diff --git a/build-logic/src/main/kotlin/org.enginehub.lin-bus.java-conventions.gradle.kts b/build-logic/src/main/kotlin/org.enginehub.lin-bus.java-conventions.gradle.kts
index 4334028..112b22a 100644
--- a/build-logic/src/main/kotlin/org.enginehub.lin-bus.java-conventions.gradle.kts
+++ b/build-logic/src/main/kotlin/org.enginehub.lin-bus.java-conventions.gradle.kts
@@ -1,8 +1,10 @@
+import org.gradle.api.plugins.quality.Checkstyle
 import org.gradle.api.tasks.SourceSetContainer
 import org.gradle.testing.jacoco.tasks.JacocoCoverageVerification
 
 plugins {
     id("org.enginehub.crankcase.java")
+    id("org.enginehub.crankcase.checkstyle")
     jacoco
 }
 
@@ -11,6 +13,15 @@ crankcaseJava {
     disabledLints.add("module")
 }
 
+crankcaseCheckstyle {
+    suppressionsFile = isolated.rootProject.projectDirectory.file("config/checkstyle/suppressions.xml")
+}
+
+tasks.withType<Checkstyle>().configureEach {
+    // Checkstyle has no grammar for module declarations: checkstyle/checkstyle#8240
+    exclude("**/module-info.java")
+}
+
 jacoco {
     toolVersion = "0.8.15"
 }
diff --git a/common/src/test/java/org/enginehub/linbus/common/internal/AbstractIteratorTest.java b/common/src/test/java/org/enginehub/linbus/common/internal/AbstractIteratorTest.java
index c4eda0a..de53661 100644
--- a/common/src/test/java/org/enginehub/linbus/common/internal/AbstractIteratorTest.java
+++ b/common/src/test/java/org/enginehub/linbus/common/internal/AbstractIteratorTest.java
@@ -123,18 +123,18 @@ private static final class CountToTen extends AbstractIterator<String> {
          * Ensures that computeNext is only called until it returns end().
          */
         private boolean tripwire = false;
-        private int i = 0;
+        private int index = 0;
 
         @Override
         protected String computeNext() {
-            if (i >= 10) {
+            if (index >= 10) {
                 if (tripwire) {
                     throw new IllegalStateException("Should not have called this!");
                 }
                 tripwire = true;
                 return end();
             }
-            i++;
+            index++;
             return "A simple test!";
         }
     }
diff --git a/config/checkstyle/suppressions.xml b/config/checkstyle/suppressions.xml
new file mode 100644
index 0000000..f9d8044
--- /dev/null
+++ b/config/checkstyle/suppressions.xml
@@ -0,0 +1,7 @@
+<?xml version="1.0"?>
+<!DOCTYPE suppressions PUBLIC
+        "-//Checkstyle//DTD SuppressionFilter Configuration 1.2//EN"
+        "https://checkstyle.org/dtds/suppressions_1_2.dtd">
+<suppressions>
+    <suppress checks="AvoidNestedBlocks" files="[\\/]src[\\/]test[\\/]"/>
+</suppressions>
diff --git a/format-snbt/src/main/java/org/enginehub/linbus/format/snbt/impl/Elusion.java b/format-snbt/src/main/java/org/enginehub/linbus/format/snbt/impl/Elusion.java
index 9910c18..4738bf4 100644
--- a/format-snbt/src/main/java/org/enginehub/linbus/format/snbt/impl/Elusion.java
+++ b/format-snbt/src/main/java/org/enginehub/linbus/format/snbt/impl/Elusion.java
@@ -23,7 +23,7 @@
  */
 public final class Elusion {
     /**
-     * Is {@code c} a character than can be emitted without quotes?
+     * Checks if {@code c} is a character that can be emitted without quotes.
      *
      * @param c character to check
      * @return {@code true} if {@code c} is a safe character
@@ -56,6 +56,7 @@ public static CharSequence escapeIfNeeded(String s) {
                 case '\'' -> singleCharCount++;
                 case '"' -> doubleCharCount++;
                 case '\\' -> backslashCount++;
+                default -> { }
             }
         }
         if (totallySafe) {
diff --git a/format-snbt/src/main/java/org/enginehub/linbus/format/snbt/impl/LinSnbtWriter.java b/format-snbt/src/main/java/org/enginehub/linbus/format/snbt/impl/LinSnbtWriter.java
index ad9d76e..41cf36c 100644
--- a/format-snbt/src/main/java/org/enginehub/linbus/format/snbt/impl/LinSnbtWriter.java
+++ b/format-snbt/src/main/java/org/enginehub/linbus/format/snbt/impl/LinSnbtWriter.java
@@ -37,7 +37,7 @@
  * Implementation of {@link LinStringIO#write(Appendable, LinStreamable)}.
  */
 public class LinSnbtWriter {
-    private sealed interface WriteState {
+    private sealed interface WriteState permits WriteState.List, WriteState.Compound, WriteState.WritingArray {
         record List(int remainingValues) implements WriteState {
         }
 
@@ -78,7 +78,7 @@ public void write(Appendable output, LinStream tokens) throws IOException {
                 break;
             }
             switch (token) {
-                case LinToken.Name(String name, Optional<LinTagId> id) -> {
+                case LinToken.Name(String name, Optional<LinTagId> _) -> {
                     if (!(state instanceof WriteState.Compound)) {
                         throw new NbtWriteException("Names can only appear inside compounds");
                     }
@@ -90,7 +90,7 @@ public void write(Appendable output, LinStream tokens) throws IOException {
                     }
                     output.append(Elusion.escapeIfNeeded(name)).append(':');
                 }
-                case LinToken.ByteArrayStart byteArrayStart -> output.append("[B;");
+                case LinToken.ByteArrayStart _ -> output.append("[B;");
                 case LinToken.ByteArrayContent(ByteBuffer buffer) -> {
                     if (state instanceof WriteState.WritingArray) {
                         output.append(',');
@@ -104,7 +104,7 @@ public void write(Appendable output, LinStream tokens) throws IOException {
                         }
                     }
                 }
-                case LinToken.ByteArrayEnd byteArrayEnd -> {
+                case LinToken.ByteArrayEnd _ -> {
                     if (state instanceof WriteState.WritingArray) {
                         stateStack.removeLast();
                     }
@@ -117,12 +117,12 @@ public void write(Appendable output, LinStream tokens) throws IOException {
 
                     handleValueEnd(output);
                 }
-                case LinToken.CompoundStart compoundStart -> {
+                case LinToken.CompoundStart _ -> {
                     output.append('{');
 
                     stateStack.addLast(WriteState.Compound.DEFAULT);
                 }
-                case LinToken.CompoundEnd compoundEnd -> {
+                case LinToken.CompoundEnd _ -> {
                     output.append('}');
 
                     stateStack.removeLast();
@@ -138,7 +138,7 @@ public void write(Appendable output, LinStream tokens) throws IOException {
 
                     handleValueEnd(output);
                 }
-                case LinToken.IntArrayStart intArrayStart -> output.append("[I;");
+                case LinToken.IntArrayStart _ -> output.append("[I;");
                 case LinToken.IntArrayContent(IntBuffer buffer) -> {
                     if (state instanceof WriteState.WritingArray) {
                         output.append(',');
@@ -152,7 +152,7 @@ public void write(Appendable output, LinStream tokens) throws IOException {
                         }
                     }
                 }
-                case LinToken.IntArrayEnd intArrayEnd -> {
+                case LinToken.IntArrayEnd _ -> {
                     if (state instanceof WriteState.WritingArray) {
                         stateStack.removeLast();
                     }
@@ -165,18 +165,18 @@ public void write(Appendable output, LinStream tokens) throws IOException {
 
                     handleValueEnd(output);
                 }
-                case LinToken.ListStart(OptionalInt size, Optional<LinTagId> elementId) -> {
+                case LinToken.ListStart(OptionalInt size, Optional<LinTagId> _) -> {
                     output.append('[');
 
                     stateStack.addLast(new WriteState.List(size.orElseThrow()));
                 }
-                case LinToken.ListEnd listEnd -> {
+                case LinToken.ListEnd _ -> {
                     output.append(']');
 
                     stateStack.removeLast();
                     handleValueEnd(output);
                 }
-                case LinToken.LongArrayStart longArrayStart -> output.append("[L;");
+                case LinToken.LongArrayStart _ -> output.append("[L;");
                 case LinToken.LongArrayContent(LongBuffer buffer) -> {
                     if (state instanceof WriteState.WritingArray) {
                         output.append(',');
@@ -190,7 +190,7 @@ public void write(Appendable output, LinStream tokens) throws IOException {
                         }
                     }
                 }
-                case LinToken.LongArrayEnd longArrayEnd -> {
+                case LinToken.LongArrayEnd _ -> {
                     if (state instanceof WriteState.WritingArray) {
                         stateStack.removeLast();
                     }
@@ -229,7 +229,7 @@ private void handleValueEnd(Appendable output) throws IOException {
                     output.append(',');
                 }
             }
-            case WriteState.Compound compound -> stateStack.addLast(WriteState.Compound.HAS_PREVIOUS_ENTRY);
+            case WriteState.Compound _ -> stateStack.addLast(WriteState.Compound.HAS_PREVIOUS_ENTRY);
             default -> throw new NbtWriteException("Unexpected state: " + state);
         }
     }
diff --git a/format-snbt/src/main/java/org/enginehub/linbus/format/snbt/impl/reader/LinSnbtReader.java b/format-snbt/src/main/java/org/enginehub/linbus/format/snbt/impl/reader/LinSnbtReader.java
index 4605570..fec197d 100644
--- a/format-snbt/src/main/java/org/enginehub/linbus/format/snbt/impl/reader/LinSnbtReader.java
+++ b/format-snbt/src/main/java/org/enginehub/linbus/format/snbt/impl/reader/LinSnbtReader.java
@@ -42,7 +42,9 @@
  */
 public class LinSnbtReader implements LinStream {
 
-    private sealed interface State {
+    private sealed interface State permits
+        State.InCompound, State.CompoundEntryName, State.InList, State.InByteArray, State.InIntArray,
+        State.InLongArray, State.ReadValue {
         /**
          * We're inside a compound right now.
          *
@@ -191,24 +193,24 @@ private NbtParseException unexpectedTokenSpecificError(SnbtToken token, String e
     private void fillTokenStack(State state) {
         switch (state) {
             case State.ReadValue readValue -> readValue(readValue);
-            case State.InCompound inCompound -> advanceCompound();
-            case State.CompoundEntryName compoundEntryName -> readName();
-            case State.InList inList -> advanceList();
-            case State.InByteArray inByteArray -> advanceArray(
+            case State.InCompound _ -> advanceCompound();
+            case State.CompoundEntryName _ -> readName();
+            case State.InList _ -> advanceList();
+            case State.InByteArray _ -> advanceArray(
                 LinToken.Byte.class,
                 ByteBuffer::allocate,
                 (buffer, t) -> buffer.put(t.value()),
                 buffer -> new LinToken.ByteArrayContent(buffer.flip().asReadOnlyBuffer()),
                 LinToken.ByteArrayEnd::new
             );
-            case State.InIntArray inIntArray -> advanceArray(
+            case State.InIntArray _ -> advanceArray(
                 LinToken.Int.class,
                 IntBuffer::allocate,
                 (buffer, t) -> buffer.put(t.value()),
                 buffer -> new LinToken.IntArrayContent(buffer.flip().asReadOnlyBuffer()),
                 LinToken.IntArrayEnd::new
             );
-            case State.InLongArray inLongArray -> advanceArray(
+            case State.InLongArray _ -> advanceArray(
                 LinToken.Long.class,
                 LongBuffer::allocate,
                 (buffer, t) -> buffer.put(t.value()),
@@ -234,7 +236,7 @@ private void readValue(State.ReadValue readValue) {
         }
 
         switch (token) {
-            case SnbtToken.ListLikeStart listLikeStart -> prepareListLike();
+            case SnbtToken.ListLikeStart _ -> prepareListLike();
             case SnbtToken.Text(boolean quoted, String content) -> {
                 var linToken = quoted ? new LinToken.String(content) : getTokenFor(content);
                 tokenQueue.addLast(linToken);
@@ -247,15 +249,15 @@ private void advanceCompound() {
         var typing = read();
         var token = typing.token();
         switch (token) {
-            case SnbtToken.Text text -> {
+            case SnbtToken.Text _ -> {
                 readAgainStack.addLast(typing);
                 stateStack.addLast(State.CompoundEntryName.INSTANCE);
             }
-            case SnbtToken.CompoundEnd compoundEnd -> {
+            case SnbtToken.CompoundEnd _ -> {
                 stateStack.removeLast();
                 tokenQueue.addLast(new LinToken.CompoundEnd());
             }
-            case SnbtToken.Separator separator -> stateStack.addLast(State.CompoundEntryName.INSTANCE);
+            case SnbtToken.Separator _ -> stateStack.addLast(State.CompoundEntryName.INSTANCE);
             default -> throw unexpectedTokenError(token);
         }
     }
@@ -278,11 +280,11 @@ private void readName() {
     private void advanceList() {
         var token = read().token();
         switch (token) {
-            case SnbtToken.ListLikeEnd listLikeEnd -> {
+            case SnbtToken.ListLikeEnd _ -> {
                 stateStack.removeLast();
                 tokenQueue.addLast(new LinToken.ListEnd());
             }
-            case SnbtToken.Separator separator -> stateStack.addLast(State.ReadValue.ANY);
+            case SnbtToken.Separator _ -> stateStack.addLast(State.ReadValue.ANY);
             default -> throw unexpectedTokenError(token);
         }
     }
@@ -361,21 +363,21 @@ private LinToken getTokenFor(String valueString) {
             case 'B', 'b' -> {
                 try {
                     yield new LinToken.Byte(Byte.parseByte(valueString.substring(0, valueString.length() - 1)));
-                } catch (NumberFormatException e) {
+                } catch (NumberFormatException _) {
                     yield new LinToken.String(valueString);
                 }
             }
             case 'L', 'l' -> {
                 try {
                     yield new LinToken.Long(Long.parseLong(valueString.substring(0, valueString.length() - 1)));
-                } catch (NumberFormatException e) {
+                } catch (NumberFormatException _) {
                     yield new LinToken.String(valueString);
                 }
             }
             case 'S', 's' -> {
                 try {
                     yield new LinToken.Short(Short.parseShort(valueString.substring(0, valueString.length() - 1)));
-                } catch (NumberFormatException e) {
+                } catch (NumberFormatException _) {
                     yield new LinToken.String(valueString);
                 }
             }
@@ -384,14 +386,14 @@ private LinToken getTokenFor(String valueString) {
             case 'F', 'f' -> {
                 try {
                     yield new LinToken.Float(Float.parseFloat(valueString.substring(0, valueString.length() - 1)));
-                } catch (NumberFormatException e) {
+                } catch (NumberFormatException _) {
                     yield new LinToken.String(valueString);
                 }
             }
             case 'D', 'd' -> {
                 try {
                     yield new LinToken.Double(Double.parseDouble(valueString.substring(0, valueString.length() - 1)));
-                } catch (NumberFormatException e) {
+                } catch (NumberFormatException _) {
                     yield new LinToken.String(valueString);
                 }
             }
@@ -399,13 +401,13 @@ private LinToken getTokenFor(String valueString) {
                 // Might be an integer.
                 try {
                     yield new LinToken.Int(Integer.parseInt(valueString));
-                } catch (NumberFormatException e) {
+                } catch (NumberFormatException _) {
                     // Nope.
                 }
                 // Might be a double.
                 try {
                     yield new LinToken.Double(Double.parseDouble(valueString));
-                } catch (NumberFormatException e) {
+                } catch (NumberFormatException _) {
                     // Nope.
                 }
                 // Might be a boolean.
diff --git a/format-snbt/src/main/java/org/enginehub/linbus/format/snbt/impl/reader/SnbtToken.java b/format-snbt/src/main/java/org/enginehub/linbus/format/snbt/impl/reader/SnbtToken.java
index d80831f..262dcde 100644
--- a/format-snbt/src/main/java/org/enginehub/linbus/format/snbt/impl/reader/SnbtToken.java
+++ b/format-snbt/src/main/java/org/enginehub/linbus/format/snbt/impl/reader/SnbtToken.java
@@ -23,7 +23,9 @@
 /**
  * Not to be confused with {@link LinToken}.
  */
-public sealed interface SnbtToken {
+public sealed interface SnbtToken permits
+    SnbtToken.CompoundStart, SnbtToken.CompoundEnd, SnbtToken.ListLikeStart, SnbtToken.ListLikeEnd,
+    SnbtToken.EntrySeparator, SnbtToken.ListTypeSeparator, SnbtToken.Separator, SnbtToken.Text {
     /**
      * '{'.
      */
@@ -55,7 +57,7 @@ public String toString() {
     }
 
     /**
-     * '['
+     * '['.
      */
     enum ListLikeStart implements SnbtToken {
         /**
@@ -70,7 +72,7 @@ public String toString() {
     }
 
     /**
-     * ']'
+     * ']'.
      */
     enum ListLikeEnd implements SnbtToken {
         /**
@@ -85,7 +87,7 @@ public String toString() {
     }
 
     /**
-     * ':'
+     * ':'.
      */
     enum EntrySeparator implements SnbtToken {
         /**
@@ -100,7 +102,7 @@ public String toString() {
     }
 
     /**
-     * ';'
+     * ';'.
      */
     enum ListTypeSeparator implements SnbtToken {
         /**
@@ -115,7 +117,7 @@ public String toString() {
     }
 
     /**
-     * ','
+     * ','.
      */
     enum Separator implements SnbtToken {
         /**
diff --git a/gradle/libs.versions.toml b/gradle/libs.versions.toml
index 33493fd..3fee9a2 100644
--- a/gradle/libs.versions.toml
+++ b/gradle/libs.versions.toml
@@ -1,7 +1,7 @@
 [versions]
 javafx = "22.0.2"
 tinylog = "2.7.0"
-crankcase = "0.1.0"
+crankcase = "0.1.1"
 
 [plugins]
 crankcase-java = { id = "org.enginehub.crankcase.java", version.ref = "crankcase" }
@@ -12,6 +12,7 @@ crankcase-release = { id = "org.enginehub.crankcase.release", version.ref = "cra
 osdetector = { id = "com.google.osdetector", version = "1.7.3" }
 
 [libraries]
+crankcase-checkstyle = { module = "org.enginehub.crankcase:checkstyle", version.ref = "crankcase" }
 crankcase-java = { module = "org.enginehub.crankcase:java", version.ref = "crankcase" }
 crankcase-javaLibrary = { module = "org.enginehub.crankcase:java-library", version.ref = "crankcase" }
 
diff --git a/gui/src/main/java/org/enginehub/linbus/gui/javafx/ArrayEditSetup.java b/gui/src/main/java/org/enginehub/linbus/gui/javafx/ArrayEditSetup.java
index 8eaffaf..26e820b 100644
--- a/gui/src/main/java/org/enginehub/linbus/gui/javafx/ArrayEditSetup.java
+++ b/gui/src/main/java/org/enginehub/linbus/gui/javafx/ArrayEditSetup.java
@@ -32,7 +32,7 @@ public class ArrayEditSetup<T extends Number> {
 
     private static <T extends Number> ListView<T> createListView(BufferObservableList<T> backingList) {
         ListView<T> listView = new ListView<>(backingList);
-        listView.setCellFactory(lv -> new SpinnerListCell<>());
+        listView.setCellFactory(_ -> new SpinnerListCell<>());
         listView.setEditable(true);
         return listView;
     }
@@ -56,7 +56,7 @@ public CompletableFuture<Boolean> showForUpdate() {
 
         dialog.show();
 
-        return MoreFutures.create((resolve, reject) -> dialog.setOnHidden(event ->
+        return MoreFutures.create((resolve, _) -> dialog.setOnHidden(_ ->
             resolve.accept(dialog.getResult() == ButtonType.APPLY)
         ));
     }
diff --git a/gui/src/main/java/org/enginehub/linbus/gui/javafx/BufferObservableList.java b/gui/src/main/java/org/enginehub/linbus/gui/javafx/BufferObservableList.java
index c85efac..039f725 100644
--- a/gui/src/main/java/org/enginehub/linbus/gui/javafx/BufferObservableList.java
+++ b/gui/src/main/java/org/enginehub/linbus/gui/javafx/BufferObservableList.java
@@ -24,7 +24,8 @@
 import java.nio.IntBuffer;
 import java.nio.LongBuffer;
 
-public sealed abstract class BufferObservableList<T> extends ModifiableObservableListBase<T> {
+public abstract sealed class BufferObservableList<T> extends ModifiableObservableListBase<T>
+    permits BufferObservableList.OfByte, BufferObservableList.OfInt, BufferObservableList.OfLong {
     @Override
     protected void doAdd(int index, T element) {
         throw new UnsupportedOperationException();
diff --git a/gui/src/main/java/org/enginehub/linbus/gui/javafx/FxSS.java b/gui/src/main/java/org/enginehub/linbus/gui/javafx/FxSS.java
index 9d01ae3..99cf106 100644
--- a/gui/src/main/java/org/enginehub/linbus/gui/javafx/FxSS.java
+++ b/gui/src/main/java/org/enginehub/linbus/gui/javafx/FxSS.java
@@ -29,8 +29,11 @@
 public final class FxSS {
     private static final String OBSERVABLE_CLASS_KEY = FxSS.class.getName() + ".observablesClasses";
 
+    private FxSS() {
+    }
+
     public static void addObservableClass(Node node, ObservableValue<@Nullable String> styleClass) {
-        ChangeListener<@Nullable String> listener = (observable, oldValue, newValue) -> {
+        ChangeListener<@Nullable String> listener = (_, oldValue, newValue) -> {
             if (oldValue != null) {
                 node.getStyleClass().remove(oldValue);
             }
@@ -47,7 +50,7 @@ public static void addObservableClass(Node node, ObservableValue<@Nullable Strin
         // Need to keep a reference to the style observable to prevent it from being garbage collected
         @SuppressWarnings("unchecked")
         var styleClassObservables = (Map<ObservableValue<String>, ChangeListener<String>>) node.getProperties().computeIfAbsent(
-            OBSERVABLE_CLASS_KEY, k -> new IdentityHashMap<>()
+            OBSERVABLE_CLASS_KEY, _ -> new IdentityHashMap<>()
         );
         styleClassObservables.put(styleClass, listener);
     }
diff --git a/gui/src/main/java/org/enginehub/linbus/gui/javafx/Icons.java b/gui/src/main/java/org/enginehub/linbus/gui/javafx/Icons.java
index c4968d7..00e509a 100644
--- a/gui/src/main/java/org/enginehub/linbus/gui/javafx/Icons.java
+++ b/gui/src/main/java/org/enginehub/linbus/gui/javafx/Icons.java
@@ -33,6 +33,9 @@
 public class Icons {
     private static final Map<LinTagId, Image> IMAGE_CACHE = new ConcurrentHashMap<>(LinTagId.values().length);
 
+    private Icons() {
+    }
+
     public static Node iconForTag(LinTag<?> tag) {
         ImageView view = new ImageView(
             IMAGE_CACHE.computeIfAbsent(tag.type().id(), Icons::initImage)
diff --git a/gui/src/main/java/org/enginehub/linbus/gui/javafx/LongSpinnerValueFactory.java b/gui/src/main/java/org/enginehub/linbus/gui/javafx/LongSpinnerValueFactory.java
index 4578a05..4bac653 100644
--- a/gui/src/main/java/org/enginehub/linbus/gui/javafx/LongSpinnerValueFactory.java
+++ b/gui/src/main/java/org/enginehub/linbus/gui/javafx/LongSpinnerValueFactory.java
@@ -48,8 +48,8 @@ public LongSpinnerValueFactory(@NamedArg("min") long min,
      * @param min The minimum allowed long value for the Spinner.
      * @param max The maximum allowed long value for the Spinner.
      * @param initialValue The value of the Spinner when first instantiated, must
-     * be within the bounds of the min and max arguments, or
-     * else the min value will be used.
+     *     be within the bounds of the min and max arguments, or
+     *     else the min value will be used.
      */
     public LongSpinnerValueFactory(@NamedArg("min") long min,
                                    @NamedArg("max") long max,
@@ -63,8 +63,8 @@ public LongSpinnerValueFactory(@NamedArg("min") long min,
      * @param min The minimum allowed long value for the Spinner.
      * @param max The maximum allowed long value for the Spinner.
      * @param initialValue The value of the Spinner when first instantiated, must
-     * be within the bounds of the min and max arguments, or
-     * else the min value will be used.
+     *     be within the bounds of the min and max arguments, or
+     *     else the min value will be used.
      * @param amountToStepBy The amount to increment or decrement by, per step.
      */
     public LongSpinnerValueFactory(@NamedArg("min") long min,
@@ -76,8 +76,10 @@ public LongSpinnerValueFactory(@NamedArg("min") long min,
         setAmountToStepBy(amountToStepBy);
         setConverter(new LongStringConverter());
 
-        valueProperty().addListener((o, oldValue, newValue) -> {
-            if (newValue == null) return;
+        valueProperty().addListener((_, _, newValue) -> {
+            if (newValue == null) {
+                return;
+            }
 
             // when the value is set, we need to react to ensure it is a
             // valid value (and if not, blow up appropriately)
@@ -126,7 +128,7 @@ public final long getMin() {
     }
 
     /**
-     * Sets the minimum allowable value for this value factory
+     * Sets the minimum allowable value for this value factory.
      *
      * @return the minimum allowable value for this value factory
      */
@@ -163,7 +165,7 @@ public final long getMax() {
     }
 
     /**
-     * Sets the maximum allowable value for this value factory
+     * Sets the maximum allowable value for this value factory.
      *
      * @return the maximum allowable value for this value factory
      */
diff --git a/gui/src/main/java/org/enginehub/linbus/gui/javafx/MainSceneSetup.java b/gui/src/main/java/org/enginehub/linbus/gui/javafx/MainSceneSetup.java
index 513d176..093ea0e 100644
--- a/gui/src/main/java/org/enginehub/linbus/gui/javafx/MainSceneSetup.java
+++ b/gui/src/main/java/org/enginehub/linbus/gui/javafx/MainSceneSetup.java
@@ -79,7 +79,7 @@ private static MenuBar menuBar(Menu fileMenu) {
 
     private Menu fileMenu(MenuItem openFile, MenuItem saveFile) {
         var exit = new MenuItem("E_xit", FontIcon.of(FontAwesomeSolid.SIGN_OUT_ALT, 16));
-        exit.setOnAction(__ -> {
+        exit.setOnAction(_ -> {
             if (checkExitOkay()) {
                 Platform.exit();
             }
@@ -100,7 +100,7 @@ private Menu fileMenu(MenuItem openFile, MenuItem saveFile) {
     private MenuItem openFile(Stage stage, ExecutorService backgroundExecutor) {
         var openFile = new MenuItem("_Open...", FontIcon.of(FontAwesomeSolid.FILE_IMPORT, 16));
         openFile.setAccelerator(new KeyCharacterCombination("O", KeyCombination.SHORTCUT_DOWN));
-        openFile.setOnAction(__ -> {
+        openFile.setOnAction(_ -> {
             var chooser = new FileChooser();
             chooser.setTitle("Choose an NBT File");
             chooser.setInitialDirectory(new File("."));
@@ -120,7 +120,7 @@ private MenuItem saveFile() {
         var saveFile = new MenuItem("_Save", FontIcon.of(FontAwesomeSolid.SAVE, 16));
         saveFile.disableProperty().bind(openPath.isNull().or(treeTableView.rootProperty().isNull()));
         saveFile.setAccelerator(new KeyCharacterCombination("S", KeyCombination.SHORTCUT_DOWN));
-        saveFile.setOnAction(__ -> trySave());
+        saveFile.setOnAction(_ -> trySave());
         return saveFile;
     }
 
@@ -185,9 +185,9 @@ private Button moveEntryUp() {
         button.disableProperty().bind(
             treeTableView.getSelectionModel().selectedItemProperty().map(item ->
                 // Disable if we don't have any parent to move up in
-                (item == null || item.getParent() == null) ||
+                (item == null || item.getParent() == null)
                     // Disable if we're the first child
-                    item.getParent().getChildren().getFirst() == item
+                    || item.getParent().getChildren().getFirst() == item
             )
         );
         button.setOnAction(event -> {
@@ -204,9 +204,9 @@ private Button moveEntryDown() {
         button.disableProperty().bind(
             treeTableView.getSelectionModel().selectedItemProperty().map(item ->
                 // Disable if we don't have any parent to move down in
-                (item == null || item.getParent() == null) ||
+                (item == null || item.getParent() == null)
                     // Disable if we're the last child
-                    item.getParent().getChildren().getLast() == item
+                    || item.getParent().getChildren().getLast() == item
             )
         );
         button.setOnAction(event -> {
diff --git a/gui/src/main/java/org/enginehub/linbus/gui/javafx/NbtTreeView.java b/gui/src/main/java/org/enginehub/linbus/gui/javafx/NbtTreeView.java
index 3c4f02b..e4c2211 100644
--- a/gui/src/main/java/org/enginehub/linbus/gui/javafx/NbtTreeView.java
+++ b/gui/src/main/java/org/enginehub/linbus/gui/javafx/NbtTreeView.java
@@ -75,7 +75,7 @@ public void changed(ObservableValue<? extends Number> observable, Number oldValu
         });
 
         treeView.getStyleClass().add("zebra");
-        treeView.setRowFactory(view -> {
+        treeView.setRowFactory(_ -> {
             TreeTableRow<TagEntry> row = new TreeTableRow<>();
             // Compensate for the lack of `:not` in JavaFX CSS
             FxSS.addObservableClass(row, row.selectedProperty().map(selected -> selected ? null : "unselected"));
@@ -87,14 +87,14 @@ public void changed(ObservableValue<? extends Number> observable, Number oldValu
     private static TreeTableColumn<TagEntry, TagEntry> createTypeNameColumn() {
         TreeTableColumn<TagEntry, TagEntry> typeNameCol = new TreeTableColumn<>("Type/Name");
         typeNameCol.setCellValueFactory(cellData -> Bindings.createObjectBinding(cellData.getValue()::getValue));
-        typeNameCol.setCellFactory(column -> new TypeNameEditableCell());
+        typeNameCol.setCellFactory(_ -> new TypeNameEditableCell());
         return typeNameCol;
     }
 
     private static TreeTableColumn<TagEntry, TagEntry> createValueColumn() {
         TreeTableColumn<TagEntry, TagEntry> valueCol = new TreeTableColumn<>("Value");
         valueCol.setCellValueFactory(cellData -> cellData.getValue().valueProperty());
-        valueCol.setCellFactory(column -> new ValueEditableCell());
+        valueCol.setCellFactory(_ -> new ValueEditableCell());
         return valueCol;
     }
 
diff --git a/gui/src/main/java/org/enginehub/linbus/gui/javafx/SpinnerListCell.java b/gui/src/main/java/org/enginehub/linbus/gui/javafx/SpinnerListCell.java
index 9dc3a38..7fb76b1 100644
--- a/gui/src/main/java/org/enginehub/linbus/gui/javafx/SpinnerListCell.java
+++ b/gui/src/main/java/org/enginehub/linbus/gui/javafx/SpinnerListCell.java
@@ -108,6 +108,7 @@ public void startEdit() {
     private Spinner<Long> initializeEditableGraphic() {
         record Result<T>(Spinner<Long> spinner, Function<Long, T> extractValue) {
         }
+
         // Safe because we checked it in the switch case labels
         @SuppressWarnings("unchecked")
         Result<T> result = switch (getItem()) {
diff --git a/gui/src/main/java/org/enginehub/linbus/gui/javafx/ValueEditableCell.java b/gui/src/main/java/org/enginehub/linbus/gui/javafx/ValueEditableCell.java
index 8e49468..0766990 100644
--- a/gui/src/main/java/org/enginehub/linbus/gui/javafx/ValueEditableCell.java
+++ b/gui/src/main/java/org/enginehub/linbus/gui/javafx/ValueEditableCell.java
@@ -72,7 +72,7 @@ private static FxFonts.AndString getFontTextForValue(NbtTreeView.TagEntry item)
             case LinByteArrayTag byteArrayTag -> bufferToString(byteArrayTag.view(), BYTES, ByteBuffer::get);
             case LinIntArrayTag intArrayTag -> bufferToString(intArrayTag.view(), INTS, IntBuffer::get);
             case LinLongArrayTag longArrayTag -> bufferToString(longArrayTag.view(), LONGS, LongBuffer::get);
-            case LinEndTag tag -> new FxFonts.AndString(FxFonts.ITALIC, "End");
+            case LinEndTag _ -> new FxFonts.AndString(FxFonts.ITALIC, "End");
             default -> new FxFonts.AndString(FxFonts.DEFAULT, item.tag().value().toString());
         };
     }
@@ -98,16 +98,17 @@ private static <B extends Buffer> FxFonts.AndString bufferToString(
 
     private static boolean isSimpleValueTag(LinTag<?> tag) {
         return !(
-            tag instanceof LinCompoundTag ||
-                tag instanceof LinListTag ||
-                tag instanceof LinByteArrayTag ||
-                tag instanceof LinIntArrayTag ||
-                tag instanceof LinLongArrayTag ||
-                tag instanceof LinEndTag
-        );
+            tag instanceof LinCompoundTag
+                || tag instanceof LinListTag
+                || tag instanceof LinByteArrayTag
+                || tag instanceof LinIntArrayTag
+                || tag instanceof LinLongArrayTag
+                || tag instanceof LinEndTag
+            );
     }
 
-    private sealed interface EditableGraphic {
+    private sealed interface EditableGraphic
+        permits EditableGraphic.Text, EditableGraphic.LongSpinner, EditableGraphic.DoubleSpinner {
 
         Node node();
 
@@ -226,9 +227,9 @@ protected void updateItem(NbtTreeView.@Nullable TagEntry item, boolean empty) {
         } else {
             setEditable(false);
 
-            if (item.tag() instanceof LinLongArrayTag ||
-                item.tag() instanceof LinIntArrayTag ||
-                item.tag() instanceof LinByteArrayTag) {
+            if (item.tag() instanceof LinLongArrayTag
+                || item.tag() instanceof LinIntArrayTag
+                || item.tag() instanceof LinByteArrayTag) {
                 // These are editable, but not directly. We use a popup for them.
                 if (doubleClickHandler == null) {
                     doubleClickHandler = event -> {
@@ -253,13 +254,13 @@ protected void updateItem(NbtTreeView.@Nullable TagEntry item, boolean empty) {
                                 }
 
                                 applyUpdate(switch (item.tag()) {
-                                    case LinByteArrayTag __ -> LinByteArrayTag.of(
+                                    case LinByteArrayTag _ -> LinByteArrayTag.of(
                                         ((BufferObservableList.OfByte) buffer).buffer().array()
                                     );
-                                    case LinIntArrayTag __ -> LinIntArrayTag.of(
+                                    case LinIntArrayTag _ -> LinIntArrayTag.of(
                                         ((BufferObservableList.OfInt) buffer).buffer().array()
                                     );
-                                    case LinLongArrayTag __ -> LinLongArrayTag.of(
+                                    case LinLongArrayTag _ -> LinLongArrayTag.of(
                                         ((BufferObservableList.OfLong) buffer).buffer().array()
                                     );
                                     default -> throw new AssertionError("Unreachable");
@@ -295,6 +296,7 @@ public void startEdit() {
     private EditableGraphic initializeEditableGraphic() {
         record Result(EditableGraphic graphic, Consumer<ActionEvent> onAction) {
         }
+
         Result result = switch (getItem().tag()) {
             case LinByteTag tag -> {
                 EditableGraphic.LongSpinner graphic = new EditableGraphic.LongSpinner(new Spinner<>(
diff --git a/gui/src/main/java/org/enginehub/linbus/gui/util/ErrorReporter.java b/gui/src/main/java/org/enginehub/linbus/gui/util/ErrorReporter.java
index 495da06..16a100e 100644
--- a/gui/src/main/java/org/enginehub/linbus/gui/util/ErrorReporter.java
+++ b/gui/src/main/java/org/enginehub/linbus/gui/util/ErrorReporter.java
@@ -44,7 +44,7 @@ private void logMessage(String message, Throwable t) {
             switch (this) {
                 case TRACK -> Logger.info(t, message);
                 case INFORM -> Logger.warn(t, message);
-                case DIE -> Logger.error(t, message);
+                default -> Logger.error(t, message);
             }
         }
     }
@@ -60,7 +60,7 @@ public static void reportError(Level level, String message, Throwable t) {
         var cf = new CompletableFuture<@Nullable Void>();
         // the whenComplete callback handles display errors and exit, so the returned future is unused
         @SuppressWarnings("FutureReturnValueIgnored")
-        CompletableFuture<@Nullable Void> _ = cf.whenComplete((value, t2) -> {
+        CompletableFuture<@Nullable Void> _ = cf.whenComplete((_, t2) -> {
             if (t2 != null) {
                 Logger.warn("Error displaying error to user", t2);
             }
@@ -71,7 +71,7 @@ public static void reportError(Level level, String message, Throwable t) {
         Platform.runLater(() -> {
             try {
                 var alert = initAlert(message, t);
-                alert.setOnHidden(e -> cf.complete(null));
+                alert.setOnHidden(_ -> cf.complete(null));
                 alert.show();
             } catch (Throwable t2) {
                 cf.completeExceptionally(t2);
@@ -119,10 +119,10 @@ private static Alert initAlert(String message, Throwable t) {
      * @param message the message to include
      *
      * @return a {@link BiConsumer} that will call {@link #reportError(Level, String, Throwable)} if given a non-null
-     * {@link Throwable}
+     *     {@link Throwable}
      */
     public static BiConsumer<Object, @Nullable Throwable> bind(Level level, String message) {
-        return (value, t) -> {
+        return (_, t) -> {
             if (t != null) {
                 reportError(level, message, t);
             }
diff --git a/gui/src/main/java/org/enginehub/linbus/gui/util/MoreFutures.java b/gui/src/main/java/org/enginehub/linbus/gui/util/MoreFutures.java
index 69e4876..ab7ef24 100644
--- a/gui/src/main/java/org/enginehub/linbus/gui/util/MoreFutures.java
+++ b/gui/src/main/java/org/enginehub/linbus/gui/util/MoreFutures.java
@@ -23,7 +23,7 @@
 import java.util.function.Consumer;
 
 public class MoreFutures {
-    public static <T>CompletableFuture<T> create(BiConsumer<Consumer<T>, Consumer<? extends Throwable>> body) {
+    public static <T> CompletableFuture<T> create(BiConsumer<Consumer<T>, Consumer<? extends Throwable>> body) {
         var future = new CompletableFuture<T>();
         try {
             body.accept(future::complete, future::completeExceptionally);
diff --git a/stream/src/main/java/org/enginehub/linbus/stream/LinBinaryIO.java b/stream/src/main/java/org/enginehub/linbus/stream/LinBinaryIO.java
index 556c6d3..5538a55 100644
--- a/stream/src/main/java/org/enginehub/linbus/stream/LinBinaryIO.java
+++ b/stream/src/main/java/org/enginehub/linbus/stream/LinBinaryIO.java
@@ -138,7 +138,7 @@ public static void write(DataOutput output, LinStreamable tokens) throws IOExcep
                 }
             }
             switch (token) {
-                case LinToken.Name(String name, Optional<LinTagId> id) ->
+                case LinToken.Name(String name, Optional<LinTagId> _) ->
                     // We need to hold this until we print the id
                     nextName = name;
                 case LinToken.ByteArrayStart(OptionalInt size) -> {
@@ -152,7 +152,7 @@ public static void write(DataOutput output, LinStreamable tokens) throws IOExcep
                     buffer.get(copy);
                     output.write(copy);
                 }
-                case LinToken.ByteArrayEnd byteArrayEnd -> {
+                case LinToken.ByteArrayEnd _ -> {
                     // Nothing to do
                 }
                 case LinToken.Byte(byte value) -> {
@@ -161,11 +161,11 @@ public static void write(DataOutput output, LinStreamable tokens) throws IOExcep
 
                     output.writeByte(value);
                 }
-                case LinToken.CompoundStart compoundStart -> {
+                case LinToken.CompoundStart _ -> {
                     writeIdAndNameIfNeeded(output, LinTagId.COMPOUND, nextName);
                     nextName = null;
                 }
-                case LinToken.CompoundEnd compoundEnd -> output.writeByte(LinTagId.END.id());
+                case LinToken.CompoundEnd _ -> output.writeByte(LinTagId.END.id());
                 case LinToken.Double(double value) -> {
                     writeIdAndNameIfNeeded(output, LinTagId.DOUBLE, nextName);
                     nextName = null;
@@ -189,7 +189,7 @@ public static void write(DataOutput output, LinStreamable tokens) throws IOExcep
                         output.writeInt(buffer.get());
                     }
                 }
-                case LinToken.IntArrayEnd intArrayEnd -> {
+                case LinToken.IntArrayEnd _ -> {
                     // Nothing to do
                 }
                 case LinToken.Int(int value) -> {
@@ -205,7 +205,7 @@ public static void write(DataOutput output, LinStreamable tokens) throws IOExcep
                     output.writeByte(elementId.orElseThrow().id());
                     output.writeInt(size.orElseThrow());
                 }
-                case LinToken.ListEnd listEnd -> {
+                case LinToken.ListEnd _ -> {
                     // Nothing to do
                 }
                 case LinToken.LongArrayStart(OptionalInt size) -> {
@@ -219,7 +219,7 @@ public static void write(DataOutput output, LinStreamable tokens) throws IOExcep
                         output.writeLong(buffer.get());
                     }
                 }
-                case LinToken.LongArrayEnd longArrayEnd -> {
+                case LinToken.LongArrayEnd _ -> {
                     // Nothing to do
                 }
                 case LinToken.Long(long value) -> {
diff --git a/stream/src/main/java/org/enginehub/linbus/stream/LinReadOptions.java b/stream/src/main/java/org/enginehub/linbus/stream/LinReadOptions.java
index b23fa95..aff30fe 100644
--- a/stream/src/main/java/org/enginehub/linbus/stream/LinReadOptions.java
+++ b/stream/src/main/java/org/enginehub/linbus/stream/LinReadOptions.java
@@ -70,9 +70,9 @@ public LinReadOptions build() {
 
         @Override
         public String toString() {
-            return "LinReadOptions.Builder{" +
-                "allowNormalUtf8Encoding=" + allowNormalUtf8Encoding +
-                '}';
+            return "LinReadOptions.Builder{"
+                + "allowNormalUtf8Encoding=" + allowNormalUtf8Encoding
+                + '}';
         }
     }
 
@@ -97,8 +97,8 @@ public boolean allowNormalUtf8Encoding() {
 
     @Override
     public String toString() {
-        return "LinReadOptions{" +
-            "allowNormalUtf8Encoding=" + allowNormalUtf8Encoding +
-            '}';
+        return "LinReadOptions{"
+            + "allowNormalUtf8Encoding=" + allowNormalUtf8Encoding
+            + '}';
     }
 }
diff --git a/stream/src/main/java/org/enginehub/linbus/stream/impl/LinNbtReader.java b/stream/src/main/java/org/enginehub/linbus/stream/impl/LinNbtReader.java
index 59f35ee..4e980fd 100644
--- a/stream/src/main/java/org/enginehub/linbus/stream/impl/LinNbtReader.java
+++ b/stream/src/main/java/org/enginehub/linbus/stream/impl/LinNbtReader.java
@@ -110,7 +110,9 @@ private static StringEncoding getGuaranteedStringEncoding(ByteBuffer bytes) {
         return StringEncoding.UNKNOWN;
     }
 
-    private sealed interface State {
+    private sealed interface State permits
+        State.Initial, State.CompoundStart, State.CompoundEntryName, State.ListEntry, State.ReadValue,
+        State.ReadByteArray, State.ReadIntArray, State.ReadLongArray {
         /**
          * We need to initialize and return the root name.
          */
@@ -204,8 +206,9 @@ String decode() throws CharacterCodingException {
             int n = (int) (sourceBuffer.remaining() * decoder.averageCharsPerByte());
             ensureCharBufferCapacity(n);
 
-            if ((n == 0) && (sourceBuffer.remaining() == 0))
+            if ((n == 0) && (sourceBuffer.remaining() == 0)) {
                 return "";
+            }
             decoder.reset();
             for (; ; ) {
                 CoderResult cr = sourceBuffer.hasRemaining()
@@ -261,18 +264,18 @@ public LinNbtReader(DataInput input, LinReadOptions options) {
         var state = stateStack.pollLast();
         return switch (state) {
             case null -> null;
-            case State.Initial initial -> {
+            case State.Initial _ -> {
                 if (input.readUnsignedByte() != LinTagId.COMPOUND.id()) {
                     throw new NbtParseException("NBT stream does not start with a compound tag");
                 }
                 stateStack.addLast(State.CompoundStart.INSTANCE);
                 yield new LinToken.Name(readUtf(), LinTagId.COMPOUND);
             }
-            case State.CompoundStart compoundStart -> {
+            case State.CompoundStart _ -> {
                 stateStack.addLast(State.CompoundEntryName.INSTANCE);
                 yield new LinToken.CompoundStart();
             }
-            case State.CompoundEntryName compoundEntryName -> {
+            case State.CompoundEntryName _ -> {
                 var id = LinTagId.fromId(input.readUnsignedByte());
                 if (id == LinTagId.END) {
                     yield new LinToken.CompoundEnd();
diff --git a/stream/src/main/java/org/enginehub/linbus/stream/impl/ValueCounter.java b/stream/src/main/java/org/enginehub/linbus/stream/impl/ValueCounter.java
index 80d44d8..e65f56a 100644
--- a/stream/src/main/java/org/enginehub/linbus/stream/impl/ValueCounter.java
+++ b/stream/src/main/java/org/enginehub/linbus/stream/impl/ValueCounter.java
@@ -51,8 +51,8 @@ public void add(LinToken token) {
             return;
         }
         switch (token) {
-            case LinToken.CompoundStart compoundStart -> compounds++;
-            case LinToken.CompoundEnd compoundEnd -> {
+            case LinToken.CompoundStart _ -> compounds++;
+            case LinToken.CompoundEnd _ -> {
                 compounds--;
                 if (compounds < 0) {
                     throw new NbtParseException("Compound end without start");
@@ -61,8 +61,8 @@ public void add(LinToken token) {
                     count++;
                 }
             }
-            case LinToken.ListStart listStart -> lists++;
-            case LinToken.ListEnd listEnd -> {
+            case LinToken.ListStart _ -> lists++;
+            case LinToken.ListEnd _ -> {
                 lists--;
                 if (lists < 0) {
                     throw new NbtParseException("List end without start");
@@ -71,8 +71,8 @@ public void add(LinToken token) {
                     count++;
                 }
             }
-            case LinToken.ByteArrayStart byteArrayStart -> arrayType = BYTE_ARRAY;
-            case LinToken.ByteArrayEnd byteArrayEnd -> {
+            case LinToken.ByteArrayStart _ -> arrayType = BYTE_ARRAY;
+            case LinToken.ByteArrayEnd _ -> {
                 if (arrayType != BYTE_ARRAY) {
                     throw new NbtParseException("Byte array end without start");
                 }
@@ -81,8 +81,8 @@ public void add(LinToken token) {
                     count++;
                 }
             }
-            case LinToken.IntArrayStart intArrayStart -> arrayType = INT_ARRAY;
-            case LinToken.IntArrayEnd intArrayEnd -> {
+            case LinToken.IntArrayStart _ -> arrayType = INT_ARRAY;
+            case LinToken.IntArrayEnd _ -> {
                 if (arrayType != INT_ARRAY) {
                     throw new NbtParseException("Int array end without start");
                 }
@@ -91,8 +91,8 @@ public void add(LinToken token) {
                     count++;
                 }
             }
-            case LinToken.LongArrayStart longArrayStart -> arrayType = LONG_ARRAY;
-            case LinToken.LongArrayEnd longArrayEnd -> {
+            case LinToken.LongArrayStart _ -> arrayType = LONG_ARRAY;
+            case LinToken.LongArrayEnd _ -> {
                 if (arrayType != LONG_ARRAY) {
                     throw new NbtParseException("Long array end without start");
                 }
diff --git a/stream/src/main/java/org/enginehub/linbus/stream/token/LinToken.java b/stream/src/main/java/org/enginehub/linbus/stream/token/LinToken.java
index 9326687..9aa567b 100644
--- a/stream/src/main/java/org/enginehub/linbus/stream/token/LinToken.java
+++ b/stream/src/main/java/org/enginehub/linbus/stream/token/LinToken.java
@@ -31,7 +31,12 @@
  */
 // token types deliberately mirror the NBT type names
 @SuppressWarnings("JavaLangClash")
-public sealed interface LinToken {
+public sealed interface LinToken permits
+    LinToken.Name, LinToken.ByteArrayStart, LinToken.ByteArrayContent, LinToken.ByteArrayEnd, LinToken.Byte,
+    LinToken.CompoundStart, LinToken.CompoundEnd, LinToken.Double, LinToken.Float, LinToken.IntArrayStart,
+    LinToken.IntArrayContent, LinToken.IntArrayEnd, LinToken.Int, LinToken.ListStart, LinToken.ListEnd,
+    LinToken.LongArrayStart, LinToken.LongArrayContent, LinToken.LongArrayEnd, LinToken.Long, LinToken.Short,
+    LinToken.String {
     /**
      * Check if this token represents a whole value on its own, i.e. there are no following tokens.
      *
diff --git a/stream/src/test/java/org/enginehub/linbus/stream/BigTestPrinter.java b/stream/src/test/java/org/enginehub/linbus/stream/BigTestPrinter.java
index 27334bd..696599d 100644
--- a/stream/src/test/java/org/enginehub/linbus/stream/BigTestPrinter.java
+++ b/stream/src/test/java/org/enginehub/linbus/stream/BigTestPrinter.java
@@ -27,6 +27,9 @@
 import java.util.zip.GZIPInputStream;
 
 public class BigTestPrinter {
+    private BigTestPrinter() {
+    }
+
     public static void main(String[] args) throws IOException {
         var resource = Resources.getResource("bigtest.nbt.gz");
         try (var stream = Resources.asByteSource(resource).openStream();
diff --git a/stream/src/test/java/org/enginehub/linbus/stream/LinBinaryIOTest.java b/stream/src/test/java/org/enginehub/linbus/stream/LinBinaryIOTest.java
index 8e36bdc..c3c3912 100644
--- a/stream/src/test/java/org/enginehub/linbus/stream/LinBinaryIOTest.java
+++ b/stream/src/test/java/org/enginehub/linbus/stream/LinBinaryIOTest.java
@@ -52,7 +52,7 @@ void readUsing() throws IOException {
             0, // name size (0)
             0,
             1, // value
-            0 // end tag
+            0, // end tag
         }), s -> ImmutableList.copyOf(s.asIterator()));
         assertThat(tokens).isNotNull();
         assertThat(tokens).isNotEmpty();
diff --git a/stream/src/test/java/org/enginehub/linbus/stream/StreamTestUtil.java b/stream/src/test/java/org/enginehub/linbus/stream/StreamTestUtil.java
index fecce74..295a40c 100644
--- a/stream/src/test/java/org/enginehub/linbus/stream/StreamTestUtil.java
+++ b/stream/src/test/java/org/enginehub/linbus/stream/StreamTestUtil.java
@@ -35,6 +35,9 @@ public interface ResourceLoader<T> {
         T load(InputStream stream) throws IOException;
     }
 
+    private StreamTestUtil() {
+    }
+
     public static <T> T loadResource(String name, ResourceLoader<T> loader) throws IOException {
         var resource = Resources.getResource(name);
         try (var stream = Resources.asByteSource(resource).openStream();
diff --git a/tree/src/main/java/org/enginehub/linbus/tree/LinByteArrayTag.java b/tree/src/main/java/org/enginehub/linbus/tree/LinByteArrayTag.java
index 7bc7045..65d670d 100644
--- a/tree/src/main/java/org/enginehub/linbus/tree/LinByteArrayTag.java
+++ b/tree/src/main/java/org/enginehub/linbus/tree/LinByteArrayTag.java
@@ -72,16 +72,16 @@ public LinStream linStream() {
             new LinToken.ByteArrayStart(value.length),
             new LinStream() {
                 private static final int BUFFER_SIZE = 4096;
-                private int i = 0;
+                private int index = 0;
 
                 @Override
                 public @Nullable LinToken nextOrNull() {
-                    if (i >= value.length) {
+                    if (index >= value.length) {
                         return null;
                     }
-                    var length = Math.min(BUFFER_SIZE, value.length - i);
-                    var buffer = ByteBuffer.wrap(value, i, length).asReadOnlyBuffer();
-                    i += length;
+                    var length = Math.min(BUFFER_SIZE, value.length - index);
+                    var buffer = ByteBuffer.wrap(value, index, length).asReadOnlyBuffer();
+                    index += length;
                     return new LinToken.ByteArrayContent(buffer);
                 }
             },
@@ -91,8 +91,12 @@ public LinStream linStream() {
 
     @Override
     public boolean equals(@Nullable Object o) {
-        if (this == o) return true;
-        if (o == null || getClass() != o.getClass()) return false;
+        if (this == o) {
+            return true;
+        }
+        if (o == null || getClass() != o.getClass()) {
+            return false;
+        }
         LinByteArrayTag that = (LinByteArrayTag) o;
         return Arrays.equals(value, that.value);
     }
diff --git a/tree/src/main/java/org/enginehub/linbus/tree/LinIntArrayTag.java b/tree/src/main/java/org/enginehub/linbus/tree/LinIntArrayTag.java
index 9905dea..f699da1 100644
--- a/tree/src/main/java/org/enginehub/linbus/tree/LinIntArrayTag.java
+++ b/tree/src/main/java/org/enginehub/linbus/tree/LinIntArrayTag.java
@@ -73,16 +73,16 @@ public LinStream linStream() {
             new LinToken.IntArrayStart(value.length),
             new LinStream() {
                 private static final int BUFFER_SIZE = 4096;
-                private int i = 0;
+                private int index = 0;
 
                 @Override
                 public @Nullable LinToken nextOrNull() {
-                    if (i >= value.length) {
+                    if (index >= value.length) {
                         return null;
                     }
-                    var length = Math.min(BUFFER_SIZE, value.length - i);
-                    var buffer = IntBuffer.wrap(value, i, length).asReadOnlyBuffer();
-                    i += length;
+                    var length = Math.min(BUFFER_SIZE, value.length - index);
+                    var buffer = IntBuffer.wrap(value, index, length).asReadOnlyBuffer();
+                    index += length;
                     return new LinToken.IntArrayContent(buffer);
                 }
             },
@@ -92,8 +92,12 @@ public LinStream linStream() {
 
     @Override
     public boolean equals(Object o) {
-        if (this == o) return true;
-        if (o == null || getClass() != o.getClass()) return false;
+        if (this == o) {
+            return true;
+        }
+        if (o == null || getClass() != o.getClass()) {
+            return false;
+        }
         LinIntArrayTag that = (LinIntArrayTag) o;
         return Arrays.equals(value, that.value);
     }
diff --git a/tree/src/main/java/org/enginehub/linbus/tree/LinLongArrayTag.java b/tree/src/main/java/org/enginehub/linbus/tree/LinLongArrayTag.java
index 156d4ef..7f1100f 100644
--- a/tree/src/main/java/org/enginehub/linbus/tree/LinLongArrayTag.java
+++ b/tree/src/main/java/org/enginehub/linbus/tree/LinLongArrayTag.java
@@ -74,16 +74,16 @@ public LinStream linStream() {
             new LinToken.LongArrayStart(value.length),
             new LinStream() {
                 private static final int BUFFER_SIZE = 4096;
-                private int i = 0;
+                private int index = 0;
 
                 @Override
                 public @Nullable LinToken nextOrNull() {
-                    if (i >= value.length) {
+                    if (index >= value.length) {
                         return null;
                     }
-                    var length = Math.min(BUFFER_SIZE, value.length - i);
-                    var buffer = LongBuffer.wrap(value, i, length).asReadOnlyBuffer();
-                    i += length;
+                    var length = Math.min(BUFFER_SIZE, value.length - index);
+                    var buffer = LongBuffer.wrap(value, index, length).asReadOnlyBuffer();
+                    index += length;
                     return new LinToken.LongArrayContent(buffer);
                 }
             },
@@ -93,8 +93,12 @@ public LinStream linStream() {
 
     @Override
     public boolean equals(Object o) {
-        if (this == o) return true;
-        if (o == null || getClass() != o.getClass()) return false;
+        if (this == o) {
+            return true;
+        }
+        if (o == null || getClass() != o.getClass()) {
+            return false;
+        }
         LinLongArrayTag that = (LinLongArrayTag) o;
         return Arrays.equals(value, that.value);
     }
diff --git a/tree/src/main/java/org/enginehub/linbus/tree/LinNumberTag.java b/tree/src/main/java/org/enginehub/linbus/tree/LinNumberTag.java
index 05029a5..b3e41bc 100644
--- a/tree/src/main/java/org/enginehub/linbus/tree/LinNumberTag.java
+++ b/tree/src/main/java/org/enginehub/linbus/tree/LinNumberTag.java
@@ -23,7 +23,7 @@
  *
  * @param <T> the specific type of number this tag represents
  */
-public sealed abstract class LinNumberTag<T extends Number> extends LinTag<T>
+public abstract sealed class LinNumberTag<T extends Number> extends LinTag<T>
     permits LinByteTag, LinDoubleTag, LinFloatTag, LinIntTag, LinLongTag, LinShortTag {
     /**
      * Constructor for subclasses.
diff --git a/tree/src/main/java/org/enginehub/linbus/tree/LinRootEntry.java b/tree/src/main/java/org/enginehub/linbus/tree/LinRootEntry.java
index 06494de..084b570 100644
--- a/tree/src/main/java/org/enginehub/linbus/tree/LinRootEntry.java
+++ b/tree/src/main/java/org/enginehub/linbus/tree/LinRootEntry.java
@@ -103,6 +103,7 @@ public byte[] writeToArray() {
 
     /**
      * {@inheritDoc}
+     *
      * <p>
      * Note that the tag returned is not the same as {@link #value()}.
      */
diff --git a/tree/src/main/java/org/enginehub/linbus/tree/LinTag.java b/tree/src/main/java/org/enginehub/linbus/tree/LinTag.java
index d1f51ee..9cbf66b 100644
--- a/tree/src/main/java/org/enginehub/linbus/tree/LinTag.java
+++ b/tree/src/main/java/org/enginehub/linbus/tree/LinTag.java
@@ -28,7 +28,7 @@
  *
  * @param <T> the type of the canonical representation
  */
-public sealed abstract class LinTag<T> implements ToLinTag<LinTag<T>>, LinStreamable
+public abstract sealed class LinTag<T> implements ToLinTag<LinTag<T>>, LinStreamable
     permits LinByteArrayTag, LinCompoundTag, LinEndTag, LinIntArrayTag, LinListTag, LinLongArrayTag, LinNumberTag, LinStringTag {
 
     /**
@@ -63,8 +63,12 @@ public final LinTag<T> toLinTag() {
     // distinct concrete tag types must never be equal
     @SuppressWarnings("EqualsGetClass")
     public boolean equals(@Nullable Object o) {
-        if (this == o) return true;
-        if (o == null || getClass() != o.getClass()) return false;
+        if (this == o) {
+            return true;
+        }
+        if (o == null || getClass() != o.getClass()) {
+            return false;
+        }
         LinTag<?> that = (LinTag<?>) o;
         return Objects.equals(value(), that.value());
     }
diff --git a/tree/src/test/java/org/enginehub/linbus/tree/LinCompoundTagTest.java b/tree/src/test/java/org/enginehub/linbus/tree/LinCompoundTagTest.java
index 0444da7..9012a5e 100644
--- a/tree/src/test/java/org/enginehub/linbus/tree/LinCompoundTagTest.java
+++ b/tree/src/test/java/org/enginehub/linbus/tree/LinCompoundTagTest.java
@@ -143,13 +143,13 @@ void transformByName() {
             "Hello", LinStringTag.of("World!"),
             "Goodbye", LinIntArrayTag.of(0xCAFE, 0xBABE)
         ));
-        var transformed = tag.transformTag("Hello", LinTagType.stringTag(), t -> LinStringTag.of("New World!"));
+        var transformed = tag.transformTag("Hello", LinTagType.stringTag(), _ -> LinStringTag.of("New World!"));
         assertThat(transformed).isEqualTo(LinCompoundTag.of(Map.of(
             "Hello", LinStringTag.of("New World!"),
             "Goodbye", LinIntArrayTag.of(0xCAFE, 0xBABE)
         )));
 
-        var transformedToNewType = tag.transformTag("Hello", LinTagType.stringTag(), t -> LinIntArrayTag.of(0xDEAD, 0xBEEF));
+        var transformedToNewType = tag.transformTag("Hello", LinTagType.stringTag(), _ -> LinIntArrayTag.of(0xDEAD, 0xBEEF));
         assertThat(transformedToNewType).isEqualTo(LinCompoundTag.of(Map.of(
             "Hello", LinIntArrayTag.of(0xDEAD, 0xBEEF),
             "Goodbye", LinIntArrayTag.of(0xCAFE, 0xBABE)
@@ -180,7 +180,7 @@ void transformRejectsEndTag() {
         var tag = LinCompoundTag.of(Map.of("Hello", LinStringTag.of("World!")));
         var ex = assertThrows(
             IllegalArgumentException.class,
-            () -> tag.transformTag("Hello", LinTagType.stringTag(), t -> LinEndTag.instance())
+            () -> tag.transformTag("Hello", LinTagType.stringTag(), _ -> LinEndTag.instance())
         );
         assertThat(ex).hasMessageThat().isEqualTo("Cannot add END tag to compound tag");
     }
@@ -190,7 +190,7 @@ void transformRejectsNullResult() {
         var tag = LinCompoundTag.of(Map.of("Hello", LinStringTag.of("World!")));
         assertThrows(
             NullPointerException.class,
-            () -> tag.transformTag("Hello", LinTagType.stringTag(), t -> null)
+            () -> tag.transformTag("Hello", LinTagType.stringTag(), _ -> null)
         );
     }
 
@@ -227,11 +227,11 @@ void transformListByName() {
     void transformIfPresentByName() {
         var tag = LinCompoundTag.of(Map.of("Hello", LinStringTag.of("World!")));
         var transformed = tag.transformTagIfPresent(
-            "Hello", LinTagType.stringTag(), t -> LinStringTag.of("New World!")
+            "Hello", LinTagType.stringTag(), _ -> LinStringTag.of("New World!")
         );
         assertThat(transformed).getTagByKey("Hello").stringValue().isEqualTo("New World!");
 
-        assertThat(tag.transformTagIfPresent("Nope", LinTagType.stringTag(), t -> LinStringTag.of("x")))
+        assertThat(tag.transformTagIfPresent("Nope", LinTagType.stringTag(), _ -> LinStringTag.of("x")))
             .isSameInstanceAs(tag);
 
         var ex = assertThrows(
@@ -269,7 +269,7 @@ void transformOrInsertByName() {
         }
         assertThrows(
             NullPointerException.class,
-            () -> tag.transformTagOrInsert("Hello", LinTagType.stringTag(), t -> null)
+            () -> tag.transformTagOrInsert("Hello", LinTagType.stringTag(), _ -> null)
         );
     }
 
diff --git a/tree/src/test/java/org/enginehub/linbus/tree/LinListTagTest.java b/tree/src/test/java/org/enginehub/linbus/tree/LinListTagTest.java
index b906bbb..66fb5a6 100644
--- a/tree/src/test/java/org/enginehub/linbus/tree/LinListTagTest.java
+++ b/tree/src/test/java/org/enginehub/linbus/tree/LinListTagTest.java
@@ -75,7 +75,7 @@ void transformByIndex() {
                 LinStringTag.of("Hello"),
                 LinStringTag.of("Goodbye...")
             ))
-        ).isEqualTo(initial.transformTag(1, s -> LinStringTag.of("Goodbye...")));
+        ).isEqualTo(initial.transformTag(1, _ -> LinStringTag.of("Goodbye...")));
     }
 
     @Test
@@ -86,7 +86,7 @@ void transformByIndexOutOfRange() {
         ));
         assertThrows(
             IndexOutOfBoundsException.class,
-            () -> initial.transformTag(2, s -> LinStringTag.of("Goodbye..."))
+            () -> initial.transformTag(2, _ -> LinStringTag.of("Goodbye..."))
         );
     }
 
diff --git a/tree/src/test/java/org/enginehub/linbus/tree/LinRootEntryTest.java b/tree/src/test/java/org/enginehub/linbus/tree/LinRootEntryTest.java
index d5f1124..a617815 100644
--- a/tree/src/test/java/org/enginehub/linbus/tree/LinRootEntryTest.java
+++ b/tree/src/test/java/org/enginehub/linbus/tree/LinRootEntryTest.java
@@ -37,7 +37,7 @@ void transformName() {
     void transformValue() {
         var root = new LinRootEntry("root", LinCompoundTag.of(Map.of("Hello", LinStringTag.of("World!"))));
         var updated = root.transformValue(
-            v -> v.transformTag("Hello", LinTagType.stringTag(), t -> LinStringTag.of("New World!"))
+            v -> v.transformTag("Hello", LinTagType.stringTag(), _ -> LinStringTag.of("New World!"))
         );
         assertThat(updated.name()).isEqualTo("root");
         assertThat(updated.value()).isEqualTo(LinCompoundTag.of(Map.of("Hello", LinStringTag.of("New World!"))));
diff --git a/tree/src/test/java/org/enginehub/linbus/tree/LinTagIntegrationTest.java b/tree/src/test/java/org/enginehub/linbus/tree/LinTagIntegrationTest.java
index 3a10f12..0acd85b 100644
--- a/tree/src/test/java/org/enginehub/linbus/tree/LinTagIntegrationTest.java
+++ b/tree/src/test/java/org/enginehub/linbus/tree/LinTagIntegrationTest.java
@@ -84,7 +84,7 @@ void bigtest() throws IOException {
         rootCompoundSubject.getTagByKey("intTest").intValue().isEqualTo(2147483647);
         rootCompoundSubject.getTagByKey("byteTest").byteValue().isEqualTo(127);
         rootCompoundSubject.getTagByKey("stringTest").stringValue()
-            .isEqualTo("HELLO WORLD THIS IS A TEST STRING \u00c5\u00c4\u00d6!");
+            .isEqualTo("HELLO WORLD THIS IS A TEST STRING ÅÄÖ!");
         for (int i = 0; i < 5; i++) {
             rootCompoundSubject.getTagByKey("listTest (long)")
                 .getTagByIndex(i).longValue().isEqualTo(11 + i);
diff --git a/tree/src/test/java/org/enginehub/linbus/tree/NestedTransformShowcaseTest.java b/tree/src/test/java/org/enginehub/linbus/tree/NestedTransformShowcaseTest.java
index 9e7a37e..27125db 100644
--- a/tree/src/test/java/org/enginehub/linbus/tree/NestedTransformShowcaseTest.java
+++ b/tree/src/test/java/org/enginehub/linbus/tree/NestedTransformShowcaseTest.java
@@ -40,7 +40,7 @@ void transformSchematicMetadata() {
         LinRootEntry withNewName = root.transformValue(v ->
             v.transformTag("Schematic", LinTagType.compoundTag(), schematic ->
                 schematic.transformTag("Metadata", LinTagType.compoundTag(), metadata ->
-                    metadata.transformTag("Name", LinTagType.stringTag(), name ->
+                    metadata.transformTag("Name", LinTagType.stringTag(), _ ->
                         LinStringTag.of("My New Schematic")
                     )
                 )
diff --git a/tree/src/test/java/org/enginehub/linbus/tree/SimpleObjectVerifier.java b/tree/src/test/java/org/enginehub/linbus/tree/SimpleObjectVerifier.java
index 115984a..2e54d01 100644
--- a/tree/src/test/java/org/enginehub/linbus/tree/SimpleObjectVerifier.java
+++ b/tree/src/test/java/org/enginehub/linbus/tree/SimpleObjectVerifier.java
@@ -25,6 +25,9 @@
  * Helper for verifying equals and hashCode implementations.
  */
 public class SimpleObjectVerifier {
+    private SimpleObjectVerifier() {
+    }
+
     // deliberately verifies the equals(null) contract
     @SuppressWarnings("EqualsNull")
     public static <T> void assertEqualsHashCodeImplementation(T base, T equal, T alsoEqual, T notEqual) {