Some Java-17ification

I might just stick on 1.18 for the rest of these refactors. Porting
across the mojmap boundary is painful.

src/main/java/dan200/computercraft/api/filesystem/FileAttributes.java

@@ -11,20 +11,14 @@ import java.time.Instant;
 
 /**
  * A simple version of {@link BasicFileAttributes}, which provides what information a {@link IMount} already exposes.
+ *
+ * @param isDirectory Whether this filesystem entry is a directory.
+ * @param size        The size of the file.
  */
-final class FileAttributes implements BasicFileAttributes
+record FileAttributes(boolean isDirectory, long size) implements BasicFileAttributes
 {
     private static final FileTime EPOCH = FileTime.from( Instant.EPOCH );
 
-    private final boolean isDirectory;
-    private final long size;
-
-    FileAttributes( boolean isDirectory, long size )
-    {
-        this.isDirectory = isDirectory;
-        this.size = size;
-    }
-
     @Override
     public FileTime lastModifiedTime()
     {
@@ -49,12 +43,6 @@ final class FileAttributes implements BasicFileAttributes
         return !isDirectory;
     }
 
-    @Override
-    public boolean isDirectory()
-    {
-        return isDirectory;
-    }
-
     @Override
     public boolean isSymbolicLink()
     {
@@ -67,12 +55,6 @@ final class FileAttributes implements BasicFileAttributes
         return false;
     }
 
-    @Override
-    public long size()
-    {
-        return size;
-    }
-
     @Override
     public Object fileKey()
     {

src/main/java/dan200/computercraft/api/lua/IArguments.java

@@ -69,8 +69,8 @@ public interface IArguments
     default double getDouble( int index ) throws LuaException
     {
         Object value = get( index );
-        if( !(value instanceof Number) ) throw LuaValues.badArgumentOf( index, "number", value );
-        return ((Number) value).doubleValue();
+        if( !(value instanceof Number number) ) throw LuaValues.badArgumentOf( index, "number", value );
+        return number.doubleValue();
     }
 
     /**
@@ -95,8 +95,8 @@ public interface IArguments
     default long getLong( int index ) throws LuaException
     {
         Object value = get( index );
-        if( !(value instanceof Number) ) throw LuaValues.badArgumentOf( index, "number", value );
-        return LuaValues.checkFiniteNum( index, (Number) value ).longValue();
+        if( !(value instanceof Number number) ) throw LuaValues.badArgumentOf( index, "number", value );
+        return LuaValues.checkFiniteNum( index, number ).longValue();
     }
 
     /**
@@ -121,8 +121,8 @@ public interface IArguments
     default boolean getBoolean( int index ) throws LuaException
     {
         Object value = get( index );
-        if( !(value instanceof Boolean) ) throw LuaValues.badArgumentOf( index, "boolean", value );
-        return (Boolean) value;
+        if( !(value instanceof Boolean bool) ) throw LuaValues.badArgumentOf( index, "boolean", value );
+        return bool;
     }
 
     /**
@@ -136,8 +136,8 @@ public interface IArguments
     default String getString( int index ) throws LuaException
     {
         Object value = get( index );
-        if( !(value instanceof String) ) throw LuaValues.badArgumentOf( index, "string", value );
-        return (String) value;
+        if( !(value instanceof String string) ) throw LuaValues.badArgumentOf( index, "string", value );
+        return string;
     }
 
     /**
@@ -213,8 +213,8 @@ public interface IArguments
     {
         Object value = get( index );
         if( value == null ) return Optional.empty();
-        if( !(value instanceof Number) ) throw LuaValues.badArgumentOf( index, "number", value );
-        return Optional.of( ((Number) value).doubleValue() );
+        if( !(value instanceof Number number) ) throw LuaValues.badArgumentOf( index, "number", value );
+        return Optional.of( number.doubleValue() );
     }
 
     /**
@@ -241,8 +241,8 @@ public interface IArguments
     {
         Object value = get( index );
         if( value == null ) return Optional.empty();
-        if( !(value instanceof Number) ) throw LuaValues.badArgumentOf( index, "number", value );
-        return Optional.of( LuaValues.checkFiniteNum( index, (Number) value ).longValue() );
+        if( !(value instanceof Number number) ) throw LuaValues.badArgumentOf( index, "number", value );
+        return Optional.of( LuaValues.checkFiniteNum( index, number ).longValue() );
     }
 
     /**
@@ -270,8 +270,8 @@ public interface IArguments
     {
         Object value = get( index );
         if( value == null ) return Optional.empty();
-        if( !(value instanceof Boolean) ) throw LuaValues.badArgumentOf( index, "boolean", value );
-        return Optional.of( (Boolean) value );
+        if( !(value instanceof Boolean bool) ) throw LuaValues.badArgumentOf( index, "boolean", value );
+        return Optional.of( bool );
     }
 
     /**
@@ -285,8 +285,8 @@ public interface IArguments
     {
         Object value = get( index );
         if( value == null ) return Optional.empty();
-        if( !(value instanceof String) ) throw LuaValues.badArgumentOf( index, "string", value );
-        return Optional.of( (String) value );
+        if( !(value instanceof String string) ) throw LuaValues.badArgumentOf( index, "string", value );
+        return Optional.of( string );
     }
 
     /**

src/main/java/dan200/computercraft/api/lua/LuaTable.java

@@ -35,9 +35,8 @@ public interface LuaTable<K, V> extends Map<K, V>
     default long getLong( int index ) throws LuaException
     {
         Object value = get( (double) index );
-        if( !(value instanceof Number) ) throw badTableItem( index, "number", getType( value ) );
+        if( !(value instanceof Number number) ) throw badTableItem( index, "number", getType( value ) );
 
-        Number number = (Number) value;
         double asDouble = number.doubleValue();
         if( !Double.isFinite( asDouble ) ) throw badTableItem( index, "number", getNumericType( asDouble ) );
         return number.longValue();
@@ -53,9 +52,8 @@ public interface LuaTable<K, V> extends Map<K, V>
     default long getLong( String key ) throws LuaException
     {
         Object value = get( key );
-        if( !(value instanceof Number) ) throw badField( key, "number", getType( value ) );
+        if( !(value instanceof Number number) ) throw badField( key, "number", getType( value ) );
 
-        Number number = (Number) value;
         double asDouble = number.doubleValue();
         if( !Double.isFinite( asDouble ) ) throw badField( key, "number", getNumericType( asDouble ) );
         return number.longValue();

src/main/java/dan200/computercraft/client/gui/OptionScreen.java

@@ -56,7 +56,7 @@ public final class OptionScreen extends Screen
 
     public static Screen unwrap( Screen screen )
     {
-        return screen instanceof OptionScreen ? ((OptionScreen) screen).getOriginalScreen() : screen;
+        return screen instanceof OptionScreen option ? option.getOriginalScreen() : screen;
     }
 
     @Override

src/main/java/dan200/computercraft/client/pocket/ClientPocketComputers.java

@@ -57,7 +57,7 @@ public final class ClientPocketComputers
     @Nonnull
     public static PocketComputerData get( ItemStack stack )
     {
-        ComputerFamily family = stack.getItem() instanceof ItemComputer ? ((ItemComputer) stack.getItem()).getFamily() : ComputerFamily.NORMAL;
+        ComputerFamily family = stack.getItem() instanceof ItemComputer computer ? computer.getFamily() : ComputerFamily.NORMAL;
         return get( ItemPocketComputer.getInstanceID( stack ), family != ComputerFamily.NORMAL );
     }
 }

src/main/java/dan200/computercraft/core/apis/OSAPI.java

@@ -39,17 +39,8 @@ public class OSAPI implements ILuaAPI
 
     private int nextAlarmToken = 0;
 
-    private static class Alarm implements Comparable<Alarm>
+    private record Alarm(double time, int day) implements Comparable<Alarm>
     {
-        final double time;
-        final int day;
-
-        Alarm( double time, int day )
-        {
-            this.time = time;
-            this.day = day;
-        }
-
         @Override
         public int compareTo( @Nonnull Alarm o )
         {

src/main/java/dan200/computercraft/core/apis/http/options/AddressRule.java

@@ -85,8 +85,8 @@ public final class AddressRule
 
         int port = socketAddress.getPort();
         InetAddress address = socketAddress.getAddress();
-        Inet4Address ipv4Address = address instanceof Inet6Address && InetAddresses.is6to4Address( (Inet6Address) address )
-            ? InetAddresses.get6to4IPv4Address( (Inet6Address) address ) : null;
+        Inet4Address ipv4Address = address instanceof Inet6Address inet6 && InetAddresses.is6to4Address( inet6 )
+            ? InetAddresses.get6to4IPv4Address( inet6 ) : null;
 
         for( AddressRule rule : rules )
         {

src/main/java/dan200/computercraft/core/apis/http/websocket/WebsocketHandler.java

@@ -61,9 +61,9 @@ public class WebsocketHandler extends SimpleChannelInboundHandler<Object>
         }
 
         WebSocketFrame frame = (WebSocketFrame) msg;
-        if( frame instanceof TextWebSocketFrame )
+        if( frame instanceof TextWebSocketFrame textFrame )
         {
-            String data = ((TextWebSocketFrame) frame).text();
+            String data = textFrame.text();
 
             websocket.environment().observe( Metrics.WEBSOCKET_INCOMING, data.length() );
             websocket.environment().queueEvent( MESSAGE_EVENT, websocket.address(), data, false );

src/main/java/dan200/computercraft/core/asm/GenericMethod.java

@@ -19,7 +19,6 @@ import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.List;
 import java.util.Objects;
-import java.util.stream.Collectors;
 import java.util.stream.Stream;
 
 /**
@@ -51,7 +50,7 @@ public class GenericMethod
     static List<GenericMethod> all()
     {
         if( cache != null ) return cache;
-        return cache = sources.stream().flatMap( GenericMethod::getMethods ).collect( Collectors.toList() );
+        return cache = sources.stream().flatMap( GenericMethod::getMethods ).toList();
     }
 
     public static synchronized void register( @Nonnull GenericSource source )
@@ -69,7 +68,7 @@ public class GenericMethod
     private static Stream<GenericMethod> getMethods( GenericSource source )
     {
         Class<?> klass = source.getClass();
-        PeripheralType type = source instanceof GenericPeripheral ? ((GenericPeripheral) source).getType() : null;
+        PeripheralType type = source instanceof GenericPeripheral generic ? generic.getType() : null;
 
         return Arrays.stream( klass.getDeclaredMethods() )
             .map( method -> {

src/main/java/dan200/computercraft/core/asm/ObjectSource.java

@@ -21,9 +21,9 @@ public interface ObjectSource
     {
         for( NamedMethod<T> method : generator.getMethods( object.getClass() ) ) accept.accept( object, method );
 
-        if( object instanceof ObjectSource )
+        if( object instanceof ObjectSource source )
         {
-            for( Object extra : ((ObjectSource) object).getExtra() )
+            for( Object extra : source.getExtra() )
             {
                 for( NamedMethod<T> method : generator.getMethods( extra.getClass() ) ) accept.accept( extra, method );
             }

src/main/java/dan200/computercraft/core/asm/Reflect.java

@@ -52,7 +52,7 @@ final class Reflect
         Type underlying = root;
         while( true )
         {
-            if( underlying instanceof Class<?> ) return (Class<?>) underlying;
+            if( underlying instanceof Class<?> klass ) return klass;
 
             if( underlying instanceof ParameterizedType type )
             {
@@ -61,7 +61,7 @@ final class Reflect
                     for( java.lang.reflect.Type arg : type.getActualTypeArguments() )
                     {
                         if( arg instanceof WildcardType ) continue;
-                        if( arg instanceof TypeVariable && ((TypeVariable<?>) arg).getName().startsWith( "capture#" ) )
+                        if( arg instanceof TypeVariable<?> var && var.getName().startsWith( "capture#" ) )
                         {
                             continue;
                         }

src/main/java/dan200/computercraft/core/computer/ComputerExecutor.java

@@ -408,7 +408,7 @@ final class ComputerExecutor
         ) );
 
         // Add the APIs. We unwrap them (yes, this is horrible) to get access to the underlying object.
-        for( ILuaAPI api : apis ) machine.addAPI( api instanceof ApiWrapper ? ((ApiWrapper) api).getDelegate() : api );
+        for( ILuaAPI api : apis ) machine.addAPI( api instanceof ApiWrapper wrapper ? wrapper.getDelegate() : api );
 
         // Start the machine running the bios resource
         MachineResult result = machine.loadBios( biosStream );
@@ -680,15 +680,7 @@ final class ComputerExecutor
         ERROR,
     }
 
-    private static final class Event
+    private record Event(String name, Object[] args)
     {
-        final String name;
-        final Object[] args;
-
-        private Event( String name, Object[] args )
-        {
-            this.name = name;
-            this.args = args;
-        }
     }
 }

src/main/java/dan200/computercraft/core/filesystem/MountWrapper.java

@@ -298,11 +298,11 @@ class MountWrapper
             if( ex.getFilename() != null ) return localExceptionOf( ex.getFilename(), ex.getMessage() );
         }
 
-        if( e instanceof java.nio.file.FileSystemException )
+        if( e instanceof java.nio.file.FileSystemException ex )
         {
             // This error will contain the absolute path, leaking information about where MC is installed. We drop that,
             // just taking the reason. We assume that the error refers to the input path.
-            String message = ((java.nio.file.FileSystemException) e).getReason().trim();
+            String message = ex.getReason().trim();
             return localPath == null ? new FileSystemException( message ) : localExceptionOf( localPath, message );
         }
 

src/main/java/dan200/computercraft/core/lua/CobaltLuaMachine.java

@@ -63,12 +63,12 @@ public class CobaltLuaMachine implements ILuaMachine
 
     public CobaltLuaMachine( MachineEnvironment environment )
     {
-        timeout = environment.timeout;
-        context = environment.context;
+        timeout = environment.timeout();
+        context = environment.context();
         debug = new TimeoutDebugHandler();
 
         // Create an environment to run in
-        MetricsObserver metrics = environment.metrics;
+        MetricsObserver metrics = environment.metrics();
         LuaState state = this.state = LuaState.builder()
             .resourceManipulator( new VoidResourceManipulator() )
             .debug( debug )
@@ -108,7 +108,7 @@ public class CobaltLuaMachine implements ILuaMachine
 
         // Add version globals
         globals.rawset( "_VERSION", valueOf( "Lua 5.1" ) );
-        globals.rawset( "_HOST", valueOf( environment.hostString ) );
+        globals.rawset( "_HOST", valueOf( environment.hostString() ) );
         globals.rawset( "_CC_DEFAULT_SETTINGS", valueOf( ComputerCraft.defaultComputerSettings ) );
         if( ComputerCraft.disableLua51Features )
         {
@@ -241,8 +241,8 @@ public class CobaltLuaMachine implements ILuaMachine
     @Nullable
     private LuaTable wrapLuaObject( Object object )
     {
-        String[] dynamicMethods = object instanceof IDynamicLuaObject
-            ? Objects.requireNonNull( ((IDynamicLuaObject) object).getMethodNames(), "Methods cannot be null" )
+        String[] dynamicMethods = object instanceof IDynamicLuaObject dynamic
+            ? Objects.requireNonNull( dynamic.getMethodNames(), "Methods cannot be null" )
             : LuaMethod.EMPTY_METHODS;
 
         LuaTable table = new LuaTable();
@@ -272,9 +272,9 @@ public class CobaltLuaMachine implements ILuaMachine
     private LuaValue toValue( @Nullable Object object, @Nullable Map<Object, LuaValue> values )
     {
         if( object == null ) return Constants.NIL;
-        if( object instanceof Number ) return valueOf( ((Number) object).doubleValue() );
-        if( object instanceof Boolean ) return valueOf( (Boolean) object );
-        if( object instanceof String ) return valueOf( object.toString() );
+        if( object instanceof Number num ) return valueOf( num.doubleValue() );
+        if( object instanceof Boolean bool ) return valueOf( bool );
+        if( object instanceof String str ) return valueOf( str );
         if( object instanceof byte[] b )
         {
             return valueOf( Arrays.copyOf( b, b.length ) );
@@ -303,12 +303,12 @@ public class CobaltLuaMachine implements ILuaMachine
             return wrapped;
         }
 
-        if( object instanceof Map )
+        if( object instanceof Map<?, ?> map )
         {
             LuaTable table = new LuaTable();
             values.put( object, table );
 
-            for( Map.Entry<?, ?> pair : ((Map<?, ?>) object).entrySet() )
+            for( Map.Entry<?, ?> pair : map.entrySet() )
             {
                 LuaValue key = toValue( pair.getKey(), values );
                 LuaValue value = toValue( pair.getValue(), values );

src/main/java/dan200/computercraft/core/lua/MachineEnvironment.java

@@ -14,36 +14,13 @@ import dan200.computercraft.core.metrics.MetricsObserver;
 /**
  * Arguments used to construct a {@link ILuaMachine}.
  *
+ * @param context    The Lua context to execute main-thread tasks with.
+ * @param metrics    A sink to submit metrics to. You do not need to submit task timings here, it should only be for additional
+ *                   metrics such as {@link Metrics#COROUTINES_CREATED}
+ * @param timeout    The current timeout state. This should be used by the machine to interrupt its execution.
+ * @param hostString A {@linkplain GlobalEnvironment#getHostString() host string} to identify the current environment.
  * @see ILuaMachine.Factory
  */
-public class MachineEnvironment
+public record MachineEnvironment(ILuaContext context, MetricsObserver metrics, TimeoutState timeout, String hostString)
 {
-    /**
-     * The Lua context to execute main-thread tasks with.
-     */
-    public final ILuaContext context;
-
-    /**
-     * A sink to submit metrics to. You do not need to submit task timings here, it should only be for additional
-     * metrics such as {@link Metrics#COROUTINES_CREATED}
-     */
-    public final MetricsObserver metrics;
-
-    /**
-     * The current timeout state. This should be used by the machine to interrupt its execution.
-     */
-    public final TimeoutState timeout;
-
-    /**
-     * A {@linkplain GlobalEnvironment#getHostString() host string} to identify the current environment.
-     */
-    public final String hostString;
-
-    public MachineEnvironment( ILuaContext context, MetricsObserver metrics, TimeoutState timeout, String hostString )
-    {
-        this.context = context;
-        this.metrics = metrics;
-        this.timeout = timeout;
-        this.hostString = hostString;
-    }
 }

src/main/java/dan200/computercraft/data/PrettyJsonWriter.java

@@ -217,25 +217,12 @@ public class PrettyJsonWriter extends JsonWriter
 
     /**
      * A key/value pair inside a JSON object.
+     *
+     * @param key   The escaped object key.
+     * @param value The object value.
      */
-    private static final class Pair
+    private record Pair(String key, Object value)
     {
-        /**
-         * The escaped object key.
-         */
-        final String key;
-
-        /**
-         * The object value.
-         */
-        final Object value;
-
-        private Pair( String key, Object value )
-        {
-            this.key = key;
-            this.value = value;
-        }
-
         int width()
         {
             return key.length() + 2 + PrettyJsonWriter.width( value );
@@ -328,9 +315,9 @@ public class PrettyJsonWriter extends JsonWriter
      */
     private static int width( Object object )
     {
-        if( object instanceof String ) return ((String) object).length();
-        if( object instanceof DocList ) return ((DocList) object).width;
-        if( object instanceof Pair ) return ((Pair) object).width();
+        if( object instanceof String string ) return string.length();
+        if( object instanceof DocList list ) return list.width;
+        if( object instanceof Pair pair ) return pair.width();
         throw new IllegalArgumentException( "Not a valid document" );
     }
 
@@ -346,19 +333,18 @@ public class PrettyJsonWriter extends JsonWriter
      */
     private static int write( Writer writer, Object object, int space, int indent ) throws IOException
     {
-        if( object instanceof String )
+        if( object instanceof String str )
         {
-            String str = (String) object;
             writer.write( str );
             return space - str.length();
         }
-        else if( object instanceof DocList )
+        else if( object instanceof DocList list )
         {
-            return ((DocList) object).write( writer, space, indent );
+            return list.write( writer, space, indent );
         }
-        else if( object instanceof Pair )
+        else if( object instanceof Pair pair )
         {
-            return ((Pair) object).write( writer, space, indent );
+            return pair.write( writer, space, indent );
         }
         else
         {

src/main/java/dan200/computercraft/shared/Registry.java

@@ -376,7 +376,7 @@ public final class Registry
         // Register media providers
         ComputerCraftAPI.registerMediaProvider( stack -> {
             Item item = stack.getItem();
-            if( item instanceof IMedia ) return (IMedia) item;
+            if( item instanceof IMedia media ) return media;
             if( item instanceof RecordItem ) return RecordMedia.INSTANCE;
             return null;
         } );

src/main/java/dan200/computercraft/shared/TurtlePermissions.java

@@ -16,7 +16,7 @@ public final class TurtlePermissions
     public static boolean isBlockEnterable( Level world, BlockPos pos, Player player )
     {
         MinecraftServer server = world.getServer();
-        return server == null || world.isClientSide || (world instanceof ServerLevel && !server.isUnderSpawnProtection( (ServerLevel) world, pos, player ));
+        return server == null || world.isClientSide || (world instanceof ServerLevel serverLevel && !server.isUnderSpawnProtection( serverLevel, pos, player ));
     }
 
     public static boolean isBlockEditable( Level world, BlockPos pos, Player player )

src/main/java/dan200/computercraft/shared/command/arguments/ComputersArgumentType.java

@@ -24,7 +24,6 @@ import java.util.*;
 import java.util.concurrent.CompletableFuture;
 import java.util.function.Function;
 import java.util.function.Predicate;
-import java.util.stream.Collectors;
 
 import static dan200.computercraft.shared.command.CommandUtils.suggest;
 import static dan200.computercraft.shared.command.CommandUtils.suggestOnServer;
@@ -163,12 +162,11 @@ public final class ComputersArgumentType implements ArgumentType<ComputersArgume
 
     private static ComputersSupplier getComputers( Predicate<ServerComputer> predicate )
     {
-        return s -> Collections.unmodifiableList( ServerContext.get( s.getServer() ).registry()
+        return s -> ServerContext.get( s.getServer() ).registry()
             .getComputers()
             .stream()
             .filter( predicate )
-            .collect( Collectors.toList() )
-        );
+            .toList();
     }
 
     public static class Serializer implements ArgumentSerializer<ComputersArgumentType>

src/main/java/dan200/computercraft/shared/command/arguments/RepeatArgumentType.java

@@ -158,7 +158,7 @@ public final class RepeatArgumentType<T, U> implements ArgumentType<List<T>>
         private static Component getMessage( RepeatArgumentType<?, ?> arg )
         {
             Message message = arg.some.create().getRawMessage();
-            if( message instanceof Component ) return (Component) message;
+            if( message instanceof Component component ) return component;
             return new TextComponent( message.getString() );
         }
     }

src/main/java/dan200/computercraft/shared/command/arguments/TrackingFieldArgumentType.java

@@ -8,8 +8,6 @@ package dan200.computercraft.shared.command.arguments;
 import dan200.computercraft.shared.command.Exceptions;
 import dan200.computercraft.shared.computer.metrics.basic.AggregatedMetric;
 
-import java.util.stream.Collectors;
-
 public final class TrackingFieldArgumentType extends ChoiceArgumentType<AggregatedMetric>
 {
     private static final TrackingFieldArgumentType INSTANCE = new TrackingFieldArgumentType();
@@ -17,7 +15,7 @@ public final class TrackingFieldArgumentType extends ChoiceArgumentType<Aggregat
     private TrackingFieldArgumentType()
     {
         super(
-            AggregatedMetric.aggregatedMetrics().collect( Collectors.toList() ),
+            AggregatedMetric.aggregatedMetrics().toList(),
             AggregatedMetric::name, AggregatedMetric::displayName, Exceptions.TRACKING_FIELD_ARG_NONE
         );
     }

src/main/java/dan200/computercraft/shared/computer/core/ServerContext.java

@@ -183,15 +183,8 @@ public final class ServerContext
         return metrics;
     }
 
-    private static final class Environment implements GlobalEnvironment
+    private record Environment(MinecraftServer server) implements GlobalEnvironment
     {
-        private final MinecraftServer server;
-
-        Environment( MinecraftServer server )
-        {
-            this.server = server;
-        }
-
         @Override
         public IMount createResourceMount( String domain, String subPath )
         {

src/main/java/dan200/computercraft/shared/computer/metrics/basic/AggregatedMetric.java

@@ -15,30 +15,14 @@ import java.util.stream.Stream;
 
 /**
  * An aggregate of a specific metric.
+ *
+ * @param metric    The metric we're aggregating.
+ * @param aggregate The aggregate to use.
  */
-public class AggregatedMetric
+public record AggregatedMetric(Metric metric, Aggregate aggregate)
 {
     private static final String TRANSLATION_PREFIX = "tracking_field.computercraft.";
 
-    private final Metric metric;
-    private final Aggregate aggregate;
-
-    public AggregatedMetric( Metric metric, Aggregate aggregate )
-    {
-        this.metric = metric;
-        this.aggregate = aggregate;
-    }
-
-    public Metric metric()
-    {
-        return metric;
-    }
-
-    public Aggregate aggregate()
-    {
-        return aggregate;
-    }
-
     public static Stream<AggregatedMetric> aggregatedMetrics()
     {
         Metrics.init();

src/main/java/dan200/computercraft/shared/computer/recipe/ComputerFamilyRecipe.java

@@ -47,7 +47,7 @@ public abstract class ComputerFamilyRecipe extends ComputerConvertRecipe
             RecipeUtil.ShapedTemplate template = RecipeUtil.getTemplate( json );
             ItemStack result = itemStackFromJson( GsonHelper.getAsJsonObject( json, "result" ) );
 
-            return create( identifier, group, template.width, template.height, template.ingredients, result, family );
+            return create( identifier, group, template.width(), template.height(), template.ingredients(), result, family );
         }
 
         @Nonnull

src/main/java/dan200/computercraft/shared/computer/upload/FileSlice.java

@@ -10,34 +10,8 @@ import dan200.computercraft.ComputerCraft;
 import java.nio.ByteBuffer;
 import java.util.List;
 
-public class FileSlice
+public record FileSlice(int fileId, int offset, ByteBuffer bytes)
 {
-    private final int fileId;
-    private final int offset;
-    private final ByteBuffer bytes;
-
-    public FileSlice( int fileId, int offset, ByteBuffer bytes )
-    {
-        this.fileId = fileId;
-        this.offset = offset;
-        this.bytes = bytes;
-    }
-
-    public int getFileId()
-    {
-        return fileId;
-    }
-
-    public int getOffset()
-    {
-        return offset;
-    }
-
-    public ByteBuffer getBytes()
-    {
-        return bytes;
-    }
-
     public void apply( List<FileUpload> files )
     {
         if( fileId < 0 || fileId >= files.size() )

src/main/java/dan200/computercraft/shared/integration/UpgradeRecipeGenerator.java

@@ -120,10 +120,8 @@ public class UpgradeRecipeGenerator<T>
     {
         setupCache();
 
-        if( stack.getItem() instanceof ItemTurtle )
+        if( stack.getItem() instanceof ItemTurtle item )
         {
-            ItemTurtle item = (ItemTurtle) stack.getItem();
-
             // Suggest possible upgrades which can be applied to this turtle
             ITurtleUpgrade left = item.getUpgrade( stack, TurtleSide.LEFT );
             ITurtleUpgrade right = item.getUpgrade( stack, TurtleSide.RIGHT );
@@ -206,9 +204,8 @@ public class UpgradeRecipeGenerator<T>
     public List<T> findRecipesWithOutput( ItemStack stack )
     {
         // Find which upgrade this item currently has, and so how we could build it.
-        if( stack.getItem() instanceof ItemTurtle )
+        if( stack.getItem() instanceof ItemTurtle item )
         {
-            ItemTurtle item = (ItemTurtle) stack.getItem();
             List<T> recipes = new ArrayList<>( 0 );
 
             ITurtleUpgrade left = item.getUpgrade( stack, TurtleSide.LEFT );

src/main/java/dan200/computercraft/shared/network/client/ComputerTerminalClientMessage.java

@@ -46,9 +46,9 @@ public class ComputerTerminalClientMessage implements NetworkMessage
     public void handle( NetworkEvent.Context context )
     {
         Player player = Minecraft.getInstance().player;
-        if( player != null && player.containerMenu.containerId == containerId && player.containerMenu instanceof ComputerMenu )
+        if( player != null && player.containerMenu.containerId == containerId && player.containerMenu instanceof ComputerMenu menu )
         {
-            ((ComputerMenu) player.containerMenu).updateTerminal( terminal );
+            menu.updateTerminal( terminal );
         }
     }
 }

src/main/java/dan200/computercraft/shared/network/server/UploadFileMessage.java

@@ -120,10 +120,10 @@ public class UploadFileMessage extends ComputerServerMessage
         buf.writeVarInt( slices.size() );
         for( FileSlice slice : slices )
         {
-            buf.writeByte( slice.getFileId() );
-            buf.writeVarInt( slice.getOffset() );
+            buf.writeByte( slice.fileId() );
+            buf.writeVarInt( slice.offset() );
 
-            ByteBuffer bytes = slice.getBytes().duplicate();
+            ByteBuffer bytes = slice.bytes().duplicate();
             buf.writeShort( bytes.remaining() );
             buf.writeBytes( bytes );
         }

src/main/java/dan200/computercraft/shared/peripheral/commandblock/CommandBlockPeripheral.java

@@ -128,9 +128,9 @@ public class CommandBlockPeripheral implements IPeripheral, ICapabilityProvider
     public static void onCapability( AttachCapabilitiesEvent<BlockEntity> event )
     {
         BlockEntity tile = event.getObject();
-        if( ComputerCraft.enableCommandBlock && tile instanceof CommandBlockEntity )
+        if( ComputerCraft.enableCommandBlock && tile instanceof CommandBlockEntity commandBlock )
         {
-            CommandBlockPeripheral peripheral = new CommandBlockPeripheral( (CommandBlockEntity) tile );
+            CommandBlockPeripheral peripheral = new CommandBlockPeripheral( commandBlock );
             event.addCapability( CAP_ID, peripheral );
             event.addListener( peripheral::invalidate );
         }

src/main/java/dan200/computercraft/shared/peripheral/generic/data/ItemData.java

@@ -19,7 +19,6 @@ import net.minecraft.world.item.enchantment.EnchantmentHelper;
 import javax.annotation.Nonnull;
 import javax.annotation.Nullable;
 import java.util.*;
-import java.util.stream.Collectors;
 
 /**
  * Data providers for items.
@@ -71,7 +70,7 @@ public class ItemData
                     .map( ItemData::parseTextComponent )
                     .filter( Objects::nonNull )
                     .map( Component::getString )
-                    .collect( Collectors.toList() ) );
+                    .toList() );
             }
         }
 

src/main/java/dan200/computercraft/shared/peripheral/monitor/MonitorWatcher.java

@@ -126,15 +126,6 @@ public final class MonitorWatcher
         return state;
     }
 
-    private static final class PlayerUpdate
-    {
-        final ServerPlayer player;
-        final TileMonitor monitor;
-
-        private PlayerUpdate( ServerPlayer player, TileMonitor monitor )
-        {
-            this.player = player;
-            this.monitor = monitor;
-        }
-    }
+    private record PlayerUpdate(ServerPlayer player, TileMonitor monitor)
+    {}
 }

src/main/java/dan200/computercraft/shared/peripheral/monitor/TileMonitor.java

@@ -241,9 +241,9 @@ public class TileMonitor extends TileGeneric
             // Otherwise fetch the origin and attempt to get its monitor
             // Note this may load chunks, but we don't really have a choice here.
             BlockEntity te = level.getBlockEntity( toWorldPos( 0, 0 ) );
-            if( !(te instanceof TileMonitor) ) return null;
+            if( !(te instanceof TileMonitor monitor) ) return null;
 
-            return serverMonitor = ((TileMonitor) te).createServerMonitor();
+            return serverMonitor = monitor.createServerMonitor();
         }
     }
 
@@ -253,9 +253,9 @@ public class TileMonitor extends TileGeneric
         if( clientMonitor != null ) return clientMonitor;
 
         BlockEntity te = level.getBlockEntity( toWorldPos( 0, 0 ) );
-        if( !(te instanceof TileMonitor) ) return null;
+        if( !(te instanceof TileMonitor monitor) ) return null;
 
-        return clientMonitor = ((TileMonitor) te).clientMonitor;
+        return clientMonitor = monitor.clientMonitor;
     }
 
     // Networking stuff
@@ -578,7 +578,7 @@ public class TileMonitor extends TileGeneric
             .of( xPos, yPos, zPos, getDirection(), getOrientation() )
             .add( xIndex, height - yIndex - 1 );
 
-        if( pair.x > width - RENDER_BORDER || pair.y > height - RENDER_BORDER || pair.x < RENDER_BORDER || pair.y < RENDER_BORDER )
+        if( pair.x() > width - RENDER_BORDER || pair.y() > height - RENDER_BORDER || pair.x() < RENDER_BORDER || pair.y() < RENDER_BORDER )
         {
             return;
         }
@@ -592,8 +592,8 @@ public class TileMonitor extends TileGeneric
         double xCharWidth = (width - (RENDER_BORDER + RENDER_MARGIN) * 2.0) / originTerminal.getWidth();
         double yCharHeight = (height - (RENDER_BORDER + RENDER_MARGIN) * 2.0) / originTerminal.getHeight();
 
-        int xCharPos = (int) Math.min( originTerminal.getWidth(), Math.max( (pair.x - RENDER_BORDER - RENDER_MARGIN) / xCharWidth + 1.0, 1.0 ) );
-        int yCharPos = (int) Math.min( originTerminal.getHeight(), Math.max( (pair.y - RENDER_BORDER - RENDER_MARGIN) / yCharHeight + 1.0, 1.0 ) );
+        int xCharPos = (int) Math.min( originTerminal.getWidth(), Math.max( (pair.x() - RENDER_BORDER - RENDER_MARGIN) / xCharWidth + 1.0, 1.0 ) );
+        int yCharPos = (int) Math.min( originTerminal.getHeight(), Math.max( (pair.y() - RENDER_BORDER - RENDER_MARGIN) / yCharHeight + 1.0, 1.0 ) );
 
         eachComputer( c -> c.queueEvent( "monitor_touch", c.getAttachmentName(), xCharPos, yCharPos ) );
     }

src/main/java/dan200/computercraft/shared/peripheral/monitor/XYPair.java

@@ -7,17 +7,8 @@ package dan200.computercraft.shared.peripheral.monitor;
 
 import net.minecraft.core.Direction;
 
-public class XYPair
+public record XYPair(float x, float y)
 {
-    public final float x;
-    public final float y;
-
-    public XYPair( float x, float y )
-    {
-        this.x = x;
-        this.y = y;
-    }
-
     public XYPair add( float x, float y )
     {
         return new XYPair( this.x + x, this.y + y );

src/main/java/dan200/computercraft/shared/turtle/core/TurtleBrain.java

@@ -786,13 +786,13 @@ public class TurtleBrain implements ITurtleAccess
 
         // Execute the command
         long start = System.nanoTime();
-        TurtleCommandResult result = nextCommand.command.execute( this );
+        TurtleCommandResult result = nextCommand.command().execute( this );
         long end = System.nanoTime();
 
         // Dispatch the callback
         if( computer == null ) return;
         computer.getComputer().getMainThreadMonitor().trackWork( end - start, TimeUnit.NANOSECONDS );
-        int callbackID = nextCommand.callbackID;
+        int callbackID = nextCommand.callbackID();
         if( callbackID < 0 ) return;
 
         if( result != null && result.isSuccess() )

src/main/java/dan200/computercraft/shared/turtle/core/TurtleCommandQueueEntry.java

@@ -7,14 +7,6 @@ package dan200.computercraft.shared.turtle.core;
 
 import dan200.computercraft.api.turtle.ITurtleCommand;
 
-public class TurtleCommandQueueEntry
+public record TurtleCommandQueueEntry(int callbackID, ITurtleCommand command)
 {
-    public final int callbackID;
-    public final ITurtleCommand command;
-
-    public TurtleCommandQueueEntry( int callbackID, ITurtleCommand command )
-    {
-        this.callbackID = callbackID;
-        this.command = command;
-    }
 }

src/main/java/dan200/computercraft/shared/util/RecipeUtil.java

@@ -25,18 +25,8 @@ public final class RecipeUtil
 {
     private RecipeUtil() {}
 
-    public static class ShapedTemplate
+    public record ShapedTemplate(int width, int height, NonNullList<Ingredient> ingredients)
     {
-        public final int width;
-        public final int height;
-        public final NonNullList<Ingredient> ingredients;
-
-        public ShapedTemplate( int width, int height, NonNullList<Ingredient> ingredients )
-        {
-            this.width = width;
-            this.height = height;
-            this.ingredients = ingredients;
-        }
     }
 
     public static ShapedTemplate getTemplate( JsonObject json )

src/test/java/dan200/computercraft/core/computer/FakeComputerManager.java

@@ -38,7 +38,7 @@ public class FakeComputerManager implements AutoCloseable
         new BasicEnvironment(),
         new ComputerThread( 1 ),
         new FakeMainThreadScheduler(),
-        args -> new DummyLuaMachine( args.timeout )
+        args -> new DummyLuaMachine( args.timeout() )
     );
 
     private final Lock errorLock = new ReentrantLock();