Replace Collections methods with {List,Map,Set}.of

The two implementations aren't entirely compatible - the implementation
returned by .of will throw an NPE on .contains(null), whereas the
Collections implementations just return false. However, we try to avoid
passing null to collections methods, so this should be safe.

There's no strong reason to do this, but it helps make the code a little
more consistent

projects/common/src/client/java/dan200/computercraft/client/gui/AbstractComputerScreen.java

@@ -33,7 +33,6 @@
 import java.nio.file.Files;
 import java.nio.file.Path;
 import java.util.ArrayList;
-import java.util.Collections;
 import java.util.List;
 import java.util.concurrent.TimeUnit;
 
@@ -219,7 +218,7 @@ public void uploadResult(UploadResult result, @Nullable Component message) {
 
     private void alert(Component title, Component message) {
         OptionScreen.show(minecraft, title, message,
-            Collections.singletonList(OptionScreen.newButton(OK, b -> minecraft.setScreen(this))),
+            List.of(OptionScreen.newButton(OK, b -> minecraft.setScreen(this))),
             () -> minecraft.setScreen(this)
         );
     }

projects/common/src/main/java/dan200/computercraft/impl/UpgradeManager.java

@@ -48,8 +48,8 @@ public record UpgradeWrapper<R extends UpgradeSerialiser<? extends T>, T extends
     private final String kind;
     private final ResourceKey<Registry<R>> registry;
 
-    private Map<String, UpgradeWrapper<R, T>> current = Collections.emptyMap();
-    private Map<T, UpgradeWrapper<R, T>> currentWrappers = Collections.emptyMap();
+    private Map<String, UpgradeWrapper<R, T>> current = Map.of();
+    private Map<T, UpgradeWrapper<R, T>> currentWrappers = Map.of();
 
     public UpgradeManager(String kind, String path, ResourceKey<Registry<R>> registry) {
         super(GSON, path);

projects/common/src/main/java/dan200/computercraft/impl/network/wired/WiredNetworkChangeImpl.java

@@ -12,7 +12,7 @@
 import java.util.Map;
 
 final class WiredNetworkChangeImpl implements WiredNetworkChange {
-    private static final WiredNetworkChangeImpl EMPTY = new WiredNetworkChangeImpl(Collections.emptyMap(), Collections.emptyMap());
+    private static final WiredNetworkChangeImpl EMPTY = new WiredNetworkChangeImpl(Map.of(), Map.of());
 
     private final Map<String, IPeripheral> removed;
     private final Map<String, IPeripheral> added;
@@ -27,21 +27,21 @@ static WiredNetworkChangeImpl changed(Map<String, IPeripheral> removed, Map<Stri
     }
 
     static WiredNetworkChangeImpl added(Map<String, IPeripheral> added) {
-        return added.isEmpty() ? EMPTY : new WiredNetworkChangeImpl(Collections.emptyMap(), Collections.unmodifiableMap(added));
+        return added.isEmpty() ? EMPTY : new WiredNetworkChangeImpl(Map.of(), Collections.unmodifiableMap(added));
     }
 
     static WiredNetworkChangeImpl removed(Map<String, IPeripheral> removed) {
-        return removed.isEmpty() ? EMPTY : new WiredNetworkChangeImpl(Collections.unmodifiableMap(removed), Collections.emptyMap());
+        return removed.isEmpty() ? EMPTY : new WiredNetworkChangeImpl(Collections.unmodifiableMap(removed), Map.of());
     }
 
     static WiredNetworkChangeImpl changeOf(Map<String, IPeripheral> oldPeripherals, Map<String, IPeripheral> newPeripherals) {
         // Handle the trivial cases, where all peripherals have been added or removed.
         if (oldPeripherals.isEmpty() && newPeripherals.isEmpty()) {
             return EMPTY;
         } else if (oldPeripherals.isEmpty()) {
-            return new WiredNetworkChangeImpl(Collections.emptyMap(), newPeripherals);
+            return new WiredNetworkChangeImpl(Map.of(), newPeripherals);
         } else if (newPeripherals.isEmpty()) {
-            return new WiredNetworkChangeImpl(oldPeripherals, Collections.emptyMap());
+            return new WiredNetworkChangeImpl(oldPeripherals, Map.of());
         }
 
         Map<String, IPeripheral> added = new HashMap<>(newPeripherals);

projects/common/src/main/java/dan200/computercraft/impl/network/wired/WiredNetworkImpl.java

@@ -56,10 +56,10 @@ public boolean connect(WiredNode nodeU, WiredNode nodeV) {
                     // Move all nodes across into this network, destroying the original nodes.
                     nodes.addAll(otherNodes);
                     for (var node : otherNodes) node.network = this;
-                    other.nodes = Collections.emptySet();
+                    other.nodes = Set.of();
 
                     // Move all peripherals across,
-                    other.peripherals = Collections.emptyMap();
+                    other.peripherals = Map.of();
                     peripherals.putAll(otherPeripherals);
 
                     if (!thisPeripherals.isEmpty()) {
@@ -216,7 +216,7 @@ public boolean remove(WiredNode node) {
             try {
                 // We special case the original node: detaching all peripherals when needed.
                 wired.network = wiredNetwork;
-                wired.peripherals = Collections.emptyMap();
+                wired.peripherals = Map.of();
 
                 // Ensure every network is finalised
                 for (var network : maximals) {
@@ -332,7 +332,7 @@ private void removeSingleNode(WiredNodeImpl wired, WiredNetworkImpl wiredNetwork
             // Detach the old peripherals then remove them from the old network
             wired.network = wiredNetwork;
             wired.neighbours.clear();
-            wired.peripherals = Collections.emptyMap();
+            wired.peripherals = Map.of();
 
             // Broadcast the change
             if (!peripherals.isEmpty()) WiredNetworkChangeImpl.removed(peripherals).broadcast(wired);

projects/common/src/main/java/dan200/computercraft/shared/command/CommandComputerCraft.java

@@ -89,7 +89,7 @@ public static void register(CommandDispatcher<CommandSourceStack> dispatcher) {
                     RequiredArgumentBuilder.<CommandSourceStack, ComputersArgumentType.ComputersSupplier>argument("computer", manyComputers())
                         .suggests((context, builder) -> Suggestions.empty())
                 )
-                .argManyValue("args", StringArgumentType.string(), Collections.emptyList())
+                .argManyValue("args", StringArgumentType.string(), List.of())
                 .executes((c, a) -> queue(getComputersArgument(c, "computer"), a)))
 
             .then(command("view")
@@ -300,7 +300,7 @@ private static int trackStop(CommandSourceStack source) throws CommandSyntaxExce
         return 1;
     }
 
-    private static final List<AggregatedMetric> DEFAULT_FIELDS = Arrays.asList(
+    private static final List<AggregatedMetric> DEFAULT_FIELDS = List.of(
         new AggregatedMetric(Metrics.COMPUTER_TASKS, Aggregate.COUNT),
         new AggregatedMetric(Metrics.COMPUTER_TASKS, Aggregate.NONE),
         new AggregatedMetric(Metrics.COMPUTER_TASKS, Aggregate.AVG)

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

@@ -32,7 +32,7 @@ public final class ComputersArgumentType implements ArgumentType<ComputersArgume
     private static final ComputersArgumentType MANY = new ComputersArgumentType(false);
     private static final ComputersArgumentType SOME = new ComputersArgumentType(true);
 
-    private static final List<String> EXAMPLES = Arrays.asList(
+    private static final List<String> EXAMPLES = List.of(
         "0", "#0", "@Label", "~Advanced"
     );
 
@@ -75,7 +75,7 @@ public ComputersSupplier parse(StringReader reader) throws CommandSyntaxExceptio
             var instance = reader.readInt();
             computers = s -> {
                 var computer = ServerContext.get(s.getServer()).registry().get(instance);
-                return computer == null ? Collections.emptyList() : Collections.singletonList(computer);
+                return computer == null ? List.of() : List.of(computer);
             };
         }
 

projects/common/src/main/java/dan200/computercraft/shared/command/builder/CommandBuilder.java

@@ -15,7 +15,6 @@
 
 import javax.annotation.Nullable;
 import java.util.ArrayList;
-import java.util.Collections;
 import java.util.List;
 import java.util.function.Predicate;
 import java.util.function.Supplier;
@@ -63,7 +62,7 @@ public <T> CommandNodeBuilder<S, ArgCommand<S, List<T>>> argManyValue(String nam
     }
 
     public <T> CommandNodeBuilder<S, ArgCommand<S, List<T>>> argManyValue(String name, ArgumentType<T> type, T defaultValue) {
-        return argManyValue(name, type, Collections.singletonList(defaultValue));
+        return argManyValue(name, type, List.of(defaultValue));
     }
 
     public <T> CommandNodeBuilder<S, ArgCommand<S, List<T>>> argMany(String name, ArgumentType<T> type, Supplier<List<T>> empty) {

projects/common/src/main/java/dan200/computercraft/shared/computer/apis/CommandAPI.java

@@ -134,12 +134,12 @@ public final long execAsync(ILuaContext context, String command) throws LuaExcep
     public final List<String> list(IArguments args) throws LuaException {
         var server = computer.getLevel().getServer();
 
-        if (server == null) return Collections.emptyList();
+        if (server == null) return List.of();
         CommandNode<CommandSourceStack> node = server.getCommands().getDispatcher().getRoot();
         for (var j = 0; j < args.count(); j++) {
             var name = args.getString(j);
             node = node.getChild(name);
-            if (!(node instanceof LiteralCommandNode)) return Collections.emptyList();
+            if (!(node instanceof LiteralCommandNode)) return List.of();
         }
 
         List<String> result = new ArrayList<>();

projects/common/src/main/java/dan200/computercraft/shared/data/BlockNamedEntityLootCondition.java

@@ -12,7 +12,6 @@
 import net.minecraft.world.level.storage.loot.predicates.LootItemCondition;
 import net.minecraft.world.level.storage.loot.predicates.LootItemConditionType;
 
-import java.util.Collections;
 import java.util.Set;
 
 /**
@@ -33,7 +32,7 @@ public boolean test(LootContext lootContext) {
 
     @Override
     public Set<LootContextParam<?>> getReferencedContextParams() {
-        return Collections.singleton(LootContextParams.BLOCK_ENTITY);
+        return Set.of(LootContextParams.BLOCK_ENTITY);
     }
 
     @Override

projects/common/src/main/java/dan200/computercraft/shared/data/HasComputerIdLootCondition.java

@@ -12,7 +12,6 @@
 import net.minecraft.world.level.storage.loot.predicates.LootItemCondition;
 import net.minecraft.world.level.storage.loot.predicates.LootItemConditionType;
 
-import java.util.Collections;
 import java.util.Set;
 
 /**
@@ -33,7 +32,7 @@ public boolean test(LootContext lootContext) {
 
     @Override
     public Set<LootContextParam<?>> getReferencedContextParams() {
-        return Collections.singleton(LootContextParams.BLOCK_ENTITY);
+        return Set.of(LootContextParams.BLOCK_ENTITY);
     }
 
     @Override

projects/common/src/main/java/dan200/computercraft/shared/data/PlayerCreativeLootCondition.java

@@ -12,7 +12,6 @@
 import net.minecraft.world.level.storage.loot.predicates.LootItemCondition;
 import net.minecraft.world.level.storage.loot.predicates.LootItemConditionType;
 
-import java.util.Collections;
 import java.util.Set;
 
 /**
@@ -33,7 +32,7 @@ public boolean test(LootContext lootContext) {
 
     @Override
     public Set<LootContextParam<?>> getReferencedContextParams() {
-        return Collections.singleton(LootContextParams.THIS_ENTITY);
+        return Set.of(LootContextParams.THIS_ENTITY);
     }
 
     @Override

projects/common/src/main/java/dan200/computercraft/shared/integration/RecipeModHelpers.java

@@ -9,22 +9,19 @@
 import dan200.computercraft.impl.PocketUpgrades;
 import dan200.computercraft.impl.TurtleUpgrades;
 import dan200.computercraft.shared.ModRegistry;
-import dan200.computercraft.shared.computer.core.ComputerFamily;
 import dan200.computercraft.shared.pocket.items.PocketComputerItem;
 import dan200.computercraft.shared.turtle.items.TurtleItem;
 import net.minecraft.resources.ResourceLocation;
 import net.minecraft.world.item.ItemStack;
 
 import java.util.ArrayList;
-import java.util.Arrays;
 import java.util.List;
 import java.util.function.Supplier;
 
 /**
  * Utilities for recipe mod plugins (such as JEI).
  */
 public final class RecipeModHelpers {
-    static final List<ComputerFamily> MAIN_FAMILIES = Arrays.asList(ComputerFamily.NORMAL, ComputerFamily.ADVANCED);
     static final List<Supplier<TurtleItem>> TURTLES = List.of(ModRegistry.Items.TURTLE_NORMAL, ModRegistry.Items.TURTLE_ADVANCED);
     static final List<Supplier<PocketComputerItem>> POCKET_COMPUTERS = List.of(ModRegistry.Items.POCKET_COMPUTER_NORMAL, ModRegistry.Items.POCKET_COMPUTER_ADVANCED);
 

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

@@ -114,7 +114,7 @@ public List<T> findRecipesWithInput(ItemStack stack) {
             // Suggest possible upgrades which can be applied to this turtle
             var left = item.getUpgradeWithData(stack, TurtleSide.LEFT);
             var right = item.getUpgradeWithData(stack, TurtleSide.RIGHT);
-            if (left != null && right != null) return Collections.emptyList();
+            if (left != null && right != null) return List.of();
 
             List<T> recipes = new ArrayList<>();
             var ingredient = Ingredient.of(stack);
@@ -135,7 +135,7 @@ public List<T> findRecipesWithInput(ItemStack stack) {
         } else if (stack.getItem() instanceof PocketComputerItem) {
             // Suggest possible upgrades which can be applied to this turtle
             var back = PocketComputerItem.getUpgrade(stack);
-            if (back != null) return Collections.emptyList();
+            if (back != null) return List.of();
 
             List<T> recipes = new ArrayList<>();
             var ingredient = Ingredient.of(stack);
@@ -148,7 +148,7 @@ public List<T> findRecipesWithInput(ItemStack stack) {
         } else {
             // If this item is usable as an upgrade, find all possible recipes.
             var upgrades = upgradeItemLookup.get(stack.getItem());
-            if (upgrades == null) return Collections.emptyList();
+            if (upgrades == null) return List.of();
 
             List<T> recipes = null;
             var multiple = false;
@@ -169,7 +169,7 @@ public List<T> findRecipesWithInput(ItemStack stack) {
                 }
             }
 
-            return recipes == null ? Collections.emptyList() : Collections.unmodifiableList(recipes);
+            return recipes == null ? List.of() : Collections.unmodifiableList(recipes);
         }
     }
 
@@ -215,7 +215,7 @@ public List<T> findRecipesWithOutput(ItemStack stack) {
 
             return Collections.unmodifiableList(recipes);
         } else {
-            return Collections.emptyList();
+            return List.of();
         }
     }
 

projects/common/src/main/java/dan200/computercraft/shared/integration/jei/JEIComputerCraft.java

@@ -22,7 +22,7 @@
 import net.minecraft.resources.ResourceLocation;
 import net.minecraft.world.item.ItemStack;
 
-import java.util.Collections;
+import java.util.List;
 
 @JeiPlugin
 public class JEIComputerCraft implements IModPlugin {
@@ -61,7 +61,7 @@ public void onRuntimeAvailable(IJeiRuntime runtime) {
         var category = registry.createRecipeLookup(RecipeTypes.CRAFTING);
         category.get().forEach(wrapper -> {
             if (RecipeModHelpers.shouldRemoveRecipe(wrapper.getId())) {
-                registry.hideRecipes(RecipeTypes.CRAFTING, Collections.singleton(wrapper));
+                registry.hideRecipes(RecipeTypes.CRAFTING, List.of(wrapper));
             }
         });
     }

projects/common/src/main/java/dan200/computercraft/shared/integration/jei/RecipeResolver.java

@@ -15,7 +15,6 @@
 import net.minecraft.world.item.ItemStack;
 import net.minecraft.world.item.crafting.CraftingRecipe;
 
-import java.util.Collections;
 import java.util.List;
 
 class RecipeResolver implements IRecipeManagerPlugin {
@@ -24,36 +23,36 @@ class RecipeResolver implements IRecipeManagerPlugin {
     @Override
     public <V> List<RecipeType<?>> getRecipeTypes(IFocus<V> focus) {
         var value = focus.getTypedValue().getIngredient();
-        if (!(value instanceof ItemStack stack)) return Collections.emptyList();
+        if (!(value instanceof ItemStack stack)) return List.of();
 
         return switch (focus.getRole()) {
             case INPUT ->
                 stack.getItem() instanceof TurtleItem || stack.getItem() instanceof PocketComputerItem || resolver.isUpgrade(stack)
-                    ? Collections.singletonList(RecipeTypes.CRAFTING)
-                    : Collections.emptyList();
+                    ? List.of(RecipeTypes.CRAFTING)
+                    : List.of();
             case OUTPUT -> stack.getItem() instanceof TurtleItem || stack.getItem() instanceof PocketComputerItem
-                ? Collections.singletonList(RecipeTypes.CRAFTING)
-                : Collections.emptyList();
-            default -> Collections.emptyList();
+                ? List.of(RecipeTypes.CRAFTING)
+                : List.of();
+            default -> List.of();
         };
     }
 
     @Override
     public <T, V> List<T> getRecipes(IRecipeCategory<T> recipeCategory, IFocus<V> focus) {
         if (!(focus.getTypedValue().getIngredient() instanceof ItemStack stack) || recipeCategory.getRecipeType() != RecipeTypes.CRAFTING) {
-            return Collections.emptyList();
+            return List.of();
         }
 
         return switch (focus.getRole()) {
             case INPUT -> cast(resolver.findRecipesWithInput(stack));
             case OUTPUT -> cast(resolver.findRecipesWithOutput(stack));
-            default -> Collections.emptyList();
+            default -> List.of();
         };
     }
 
     @Override
     public <T> List<T> getRecipes(IRecipeCategory<T> recipeCategory) {
-        return Collections.emptyList();
+        return List.of();
     }
 
     @SuppressWarnings({ "unchecked", "rawtypes" })

projects/common/src/main/java/dan200/computercraft/shared/peripheral/modem/wired/CableBlockEntity.java

@@ -30,7 +30,7 @@
 import net.minecraft.world.phys.Vec3;
 
 import javax.annotation.Nullable;
-import java.util.Collections;
+import java.util.Map;
 import java.util.Objects;
 
 public class CableBlockEntity extends BlockEntity {
@@ -274,7 +274,7 @@ void modemChanged() {
         if (!canAttachPeripheral() && peripheralAccessAllowed) {
             peripheralAccessAllowed = false;
             peripheral.detach();
-            node.updatePeripherals(Collections.emptyMap());
+            node.updatePeripherals(Map.of());
             setChanged();
             updateBlockState();
         }
@@ -291,7 +291,7 @@ private void togglePeripheralAccess() {
             peripheral.detach();
 
             peripheralAccessAllowed = false;
-            node.updatePeripherals(Collections.emptyMap());
+            node.updatePeripherals(Map.of());
         }
 
         updateBlockState();