Add InputMethods, Close #574

16 files changed, 257 insertions, 19 deletions

diff --git a/api/src/main/java/me/shedaniel/rei/api/client/config/ConfigObject.java b/api/src/main/java/me/shedaniel/rei/api/client/config/ConfigObject.java
index 3b0e0efbb..4da17b6c0 100644
--- a/api/src/main/java/me/shedaniel/rei/api/client/config/ConfigObject.java
+++ b/api/src/main/java/me/shedaniel/rei/api/client/config/ConfigObject.java
@@ -30,7 +30,9 @@ import me.shedaniel.rei.api.client.favorites.FavoriteEntry;
 import me.shedaniel.rei.api.client.gui.config.*;
 import net.fabricmc.api.EnvType;
 import net.fabricmc.api.Environment;
+import net.minecraft.resources.ResourceLocation;
 import org.jetbrains.annotations.ApiStatus;
+import org.jetbrains.annotations.Nullable;
 
 import java.util.List;
 
@@ -235,6 +237,10 @@ public interface ConfigObject {
      */
     int getMaxRecipesPageHeight();
     
+    @ApiStatus.Experimental
+    @Nullable
+    ResourceLocation getInputMethodId();
+    
     boolean doesDisableRecipeBook();
     
     boolean doesFixTabCloseContainer();
diff --git a/api/src/main/java/me/shedaniel/rei/api/client/gui/Renderer.java b/api/src/main/java/me/shedaniel/rei/api/client/gui/Renderer.java
index c0a40c0ec..0d1f14184 100644
--- a/api/src/main/java/me/shedaniel/rei/api/client/gui/Renderer.java
+++ b/api/src/main/java/me/shedaniel/rei/api/client/gui/Renderer.java
@@ -24,7 +24,6 @@
 package me.shedaniel.rei.api.client.gui;
 
 import com.mojang.blaze3d.vertex.PoseStack;
-import me.shedaniel.math.Point;
 import me.shedaniel.math.Rectangle;
 import me.shedaniel.rei.api.client.gui.widgets.Tooltip;
 import me.shedaniel.rei.api.client.gui.widgets.TooltipContext;
diff --git a/api/src/main/java/me/shedaniel/rei/api/client/gui/config/SearchFieldLocation.java b/api/src/main/java/me/shedaniel/rei/api/client/gui/config/SearchFieldLocation.java
index 762ae020f..82d722359 100644
--- a/api/src/main/java/me/shedaniel/rei/api/client/gui/config/SearchFieldLocation.java
+++ b/api/src/main/java/me/shedaniel/rei/api/client/gui/config/SearchFieldLocation.java
@@ -37,6 +37,6 @@ public enum SearchFieldLocation {
     
     @Override
     public String toString() {
-        return I18n.get("config.roughlyenoughitems.layout.searchFieldLocation.%s", name().toLowerCase(Locale.ROOT));
+        return I18n.get("config.roughlyenoughitems.layout.searchFieldLocation.%s".formatted(name().toLowerCase(Locale.ROOT)));
     }
 }
diff --git a/api/src/main/java/me/shedaniel/rei/api/client/gui/widgets/Label.java b/api/src/main/java/me/shedaniel/rei/api/client/gui/widgets/Label.java
index 0533988d2..9b5432c82 100644
--- a/api/src/main/java/me/shedaniel/rei/api/client/gui/widgets/Label.java
+++ b/api/src/main/java/me/shedaniel/rei/api/client/gui/widgets/Label.java
@@ -28,14 +28,11 @@ import me.shedaniel.math.Point;
 import me.shedaniel.rei.api.client.REIRuntime;
 import net.minecraft.network.chat.Component;
 import net.minecraft.network.chat.FormattedText;
-import net.minecraft.network.chat.TextComponent;
-import org.jetbrains.annotations.ApiStatus;
 import org.jetbrains.annotations.Nullable;
 
 import java.util.function.BiConsumer;
 import java.util.function.Consumer;
 import java.util.function.Function;
-import java.util.stream.Stream;
 
 public abstract class Label extends WidgetWithBounds {
     public static final int LEFT_ALIGNED = -1;
diff --git a/api/src/main/java/me/shedaniel/rei/api/client/gui/widgets/Tooltip.java b/api/src/main/java/me/shedaniel/rei/api/client/gui/widgets/Tooltip.java
index dad0e9d59..b5f09e6f5 100644
--- a/api/src/main/java/me/shedaniel/rei/api/client/gui/widgets/Tooltip.java
+++ b/api/src/main/java/me/shedaniel/rei/api/client/gui/widgets/Tooltip.java
@@ -32,7 +32,6 @@ import me.shedaniel.rei.api.common.util.CollectionUtils;
 import me.shedaniel.rei.impl.ClientInternals;
 import net.fabricmc.api.EnvType;
 import net.fabricmc.api.Environment;
-import net.minecraft.client.gui.screens.inventory.tooltip.ClientTooltipComponent;
 import net.minecraft.network.chat.Component;
 import net.minecraft.world.inventory.tooltip.TooltipComponent;
 import org.jetbrains.annotations.ApiStatus;
diff --git a/api/src/main/java/me/shedaniel/rei/api/client/overlay/ScreenOverlay.java b/api/src/main/java/me/shedaniel/rei/api/client/overlay/ScreenOverlay.java
index a45a854b7..f7f5c481e 100644
--- a/api/src/main/java/me/shedaniel/rei/api/client/overlay/ScreenOverlay.java
+++ b/api/src/main/java/me/shedaniel/rei/api/client/overlay/ScreenOverlay.java
@@ -27,17 +27,15 @@ import me.shedaniel.rei.api.client.gui.drag.DraggingContext;
 import me.shedaniel.rei.api.client.gui.widgets.WidgetWithBounds;
 import net.fabricmc.api.EnvType;
 import net.fabricmc.api.Environment;
-import org.jetbrains.annotations.ApiStatus;
 
 import java.util.Optional;
 
 @Environment(EnvType.CLIENT)
 public abstract class ScreenOverlay extends WidgetWithBounds {
-    @ApiStatus.Internal
-    public abstract void closeOverlayMenu();
-    
     public abstract void queueReloadOverlay();
     
+    public abstract void queueReloadSearch();
+    
     public abstract DraggingContext<?> getDraggingContext();
     
     public abstract boolean isNotInExclusionZones(double mouseX, double mouseY);
diff --git a/api/src/main/java/me/shedaniel/rei/api/client/plugins/REIClientPlugin.java b/api/src/main/java/me/shedaniel/rei/api/client/plugins/REIClientPlugin.java
index f3ff9408d..deeca9ff3 100644
--- a/api/src/main/java/me/shedaniel/rei/api/client/plugins/REIClientPlugin.java
+++ b/api/src/main/java/me/shedaniel/rei/api/client/plugins/REIClientPlugin.java
@@ -33,6 +33,7 @@ import me.shedaniel.rei.api.client.registry.entry.EntryRegistry;
 import me.shedaniel.rei.api.client.registry.screen.ExclusionZones;
 import me.shedaniel.rei.api.client.registry.screen.ScreenRegistry;
 import me.shedaniel.rei.api.client.registry.transfer.TransferHandlerRegistry;
+import me.shedaniel.rei.api.client.search.method.InputMethodRegistry;
 import me.shedaniel.rei.api.client.subsets.SubsetsRegistry;
 import me.shedaniel.rei.api.common.plugins.REIPlugin;
 import net.fabricmc.api.EnvType;
@@ -145,6 +146,17 @@ public interface REIClientPlugin extends REIPlugin<REIClientPlugin> {
     default void registerConfigAddons(ConfigAddonRegistry registry) {
     }
     
+    /**
+     * Registers new input methods.
+     *
+     * @param registry the registry
+     * @since 8.3
+     */
+    @ApiStatus.OverrideOnly
+    @ApiStatus.Experimental
+    default void registerInputMethods(InputMethodRegistry registry) {
+    }
+    
     @Override
     default Class<REIClientPlugin> getPluginProviderClass() {
         return REIClientPlugin.class;
diff --git a/api/src/main/java/me/shedaniel/rei/api/client/registry/transfer/TransferHandler.java b/api/src/main/java/me/shedaniel/rei/api/client/registry/transfer/TransferHandler.java
index 9b2cb8691..d363e9411 100644
--- a/api/src/main/java/me/shedaniel/rei/api/client/registry/transfer/TransferHandler.java
+++ b/api/src/main/java/me/shedaniel/rei/api/client/registry/transfer/TransferHandler.java
@@ -27,12 +27,10 @@ import me.shedaniel.math.Point;
 import me.shedaniel.rei.api.client.gui.widgets.Tooltip;
 import me.shedaniel.rei.api.common.display.Display;
 import me.shedaniel.rei.api.common.entry.EntryIngredient;
-import me.shedaniel.rei.api.common.entry.EntryStack;
 import me.shedaniel.rei.impl.ClientInternals;
 import net.fabricmc.api.EnvType;
 import net.fabricmc.api.Environment;
 import net.minecraft.client.Minecraft;
-import net.minecraft.client.gui.screens.Screen;
 import net.minecraft.client.gui.screens.inventory.AbstractContainerScreen;
 import net.minecraft.network.chat.Component;
 import net.minecraft.world.inventory.AbstractContainerMenu;
diff --git a/api/src/main/java/me/shedaniel/rei/api/client/search/SearchProvider.java b/api/src/main/java/me/shedaniel/rei/api/client/search/SearchProvider.java
index b31c4ee16..a337e5e17 100644
--- a/api/src/main/java/me/shedaniel/rei/api/client/search/SearchProvider.java
+++ b/api/src/main/java/me/shedaniel/rei/api/client/search/SearchProvider.java
@@ -24,10 +24,12 @@
 package me.shedaniel.rei.api.client.search;
 
 import me.shedaniel.rei.api.client.plugins.REIClientPlugin;
+import me.shedaniel.rei.api.client.search.method.InputMethod;
 import me.shedaniel.rei.api.common.plugins.PluginManager;
 import me.shedaniel.rei.api.common.registry.Reloadable;
 import net.fabricmc.api.EnvType;
 import net.fabricmc.api.Environment;
+import org.jetbrains.annotations.ApiStatus;
 
 @Environment(EnvType.CLIENT)
 public interface SearchProvider extends Reloadable<REIClientPlugin> {
@@ -39,8 +41,21 @@ public interface SearchProvider extends Reloadable<REIClientPlugin> {
      * Creates a search filter, which respects user's config options and
      * respects argument prefixes.
      *
-     * @param searchTerm the search term of the filter
+     * @param filter the search term of the filter
      * @return the search filter
      */
-    SearchFilter createFilter(String searchTerm);
+    default SearchFilter createFilter(String filter) {
+        return createFilter(filter, InputMethod.active());
+    }
+    
+    /**
+     * Creates a search filter, which respects user's config options and
+     * respects argument prefixes.
+     *
+     * @param filter      the search term of the filter
+     * @param inputMethod the input method of the filter
+     * @return the search filter
+     */
+    @ApiStatus.Experimental
+    SearchFilter createFilter(String filter, InputMethod<?> inputMethod);
 }
diff --git a/api/src/main/java/me/shedaniel/rei/api/client/search/method/CharacterUnpackingInputMethod.java b/api/src/main/java/me/shedaniel/rei/api/client/search/method/CharacterUnpackingInputMethod.java
new file mode 100644
index 000000000..f14e1b334
--- /dev/null
+++ b/api/src/main/java/me/shedaniel/rei/api/client/search/method/CharacterUnpackingInputMethod.java
@@ -0,0 +1,61 @@
+/*
+ * This file is licensed under the MIT License, part of Roughly Enough Items.
+ * Copyright (c) 2018, 2019, 2020, 2021, 2022 shedaniel
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+package me.shedaniel.rei.api.client.search.method;
+
+import it.unimi.dsi.fastutil.ints.IntList;
+import org.jetbrains.annotations.ApiStatus;
+import org.jetbrains.annotations.Nullable;
+
+import java.util.List;
+import java.util.stream.Collectors;
+
+@ApiStatus.Experimental
+public interface CharacterUnpackingInputMethod extends InputMethod<IntList> {
+    List<ExpendedChar> expendSourceChar(int codePoint);
+    
+    @Override
+    default boolean contains(String str, IntList substr) {
+        // This is implemented in the runtime
+        throw new UnsupportedOperationException();
+    }
+    
+    @Override
+    @Nullable
+    default String suggestInputString(String str) {
+        return str.codePoints().mapToObj(c -> {
+            List<ExpendedChar> chars = expendSourceChar(c);
+            String result;
+            if (chars.isEmpty()) return result = ((char) c) + "";
+            result = chars.get(0).phonemes().stream()
+                    .flatMap(integers -> integers.intStream().mapToObj(value -> ((char) value) + ""))
+                    .collect(Collectors.joining());
+            if (result.codePointCount(0, result.length()) == 1 && result.codePointAt(0) == c) {
+                return result;
+            }
+            return " " + result + " ";
+        }).collect(Collectors.joining()).trim().replace("  ", " ");
+    }
+    
+    record ExpendedChar(List<IntList> phonemes) {}
+}
diff --git a/api/src/main/java/me/shedaniel/rei/api/client/search/method/InputMethod.java b/api/src/main/java/me/shedaniel/rei/api/client/search/method/InputMethod.java
new file mode 100644
index 000000000..90e6ba092
--- /dev/null
+++ b/api/src/main/java/me/shedaniel/rei/api/client/search/method/InputMethod.java
@@ -0,0 +1,68 @@
+/*
+ * This file is licensed under the MIT License, part of Roughly Enough Items.
+ * Copyright (c) 2018, 2019, 2020, 2021, 2022 shedaniel
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+package me.shedaniel.rei.api.client.search.method;
+
+import me.shedaniel.rei.api.client.config.ConfigObject;
+import me.shedaniel.rei.api.common.util.CollectionUtils;
+import net.minecraft.client.Minecraft;
+import net.minecraft.network.chat.Component;
+import org.jetbrains.annotations.ApiStatus;
+import org.jetbrains.annotations.Nullable;
+
+import java.util.List;
+import java.util.concurrent.CompletableFuture;
+import java.util.concurrent.Executor;
+
+@ApiStatus.Experimental
+public interface InputMethod<T> {
+    static InputMethod<?> active() {
+        return InputMethodRegistry.getInstance().getOrDefault(ConfigObject.getInstance().getInputMethodId());
+    }
+    
+    static List<Locale> getAllLocales() {
+        return CollectionUtils.map(Minecraft.getInstance().getLanguageManager().getLanguages(), info ->
+                new Locale(info.getCode(), Component.literal(info.getName())));
+    }
+    
+    List<Locale> getMatchingLocales();
+    
+    Iterable<T> expendFilter(String filter);
+    
+    boolean contains(String str, T substr);
+    
+    @Nullable
+    default String suggestInputString(String str) {
+        return null;
+    }
+    
+    CompletableFuture<Void> prepare(Executor executor);
+    
+    CompletableFuture<Void> dispose(Executor executor);
+    
+    Component getName();
+    
+    Component getDescription();
+    
+    record Locale(String code, Component name) {}
+}
diff --git a/api/src/main/java/me/shedaniel/rei/api/client/search/method/InputMethodRegistry.java b/api/src/main/java/me/shedaniel/rei/api/client/search/method/InputMethodRegistry.java
new file mode 100644
index 000000000..357a182cd
--- /dev/null
+++ b/api/src/main/java/me/shedaniel/rei/api/client/search/method/InputMethodRegistry.java
@@ -0,0 +1,49 @@
+/*
+ * This file is licensed under the MIT License, part of Roughly Enough Items.
+ * Copyright (c) 2018, 2019, 2020, 2021, 2022 shedaniel
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+package me.shedaniel.rei.api.client.search.method;
+
+import me.shedaniel.rei.api.client.plugins.REIClientPlugin;
+import me.shedaniel.rei.api.common.plugins.PluginManager;
+import me.shedaniel.rei.api.common.registry.Reloadable;
+import net.minecraft.resources.ResourceLocation;
+import org.jetbrains.annotations.ApiStatus;
+import org.jetbrains.annotations.Nullable;
+
+import java.util.Map;
+
+@ApiStatus.Experimental
+public interface InputMethodRegistry extends Reloadable<REIClientPlugin> {
+    static InputMethodRegistry getInstance() {
+        return PluginManager.getClientInstance().get(InputMethodRegistry.class);
+    }
+    
+    void add(ResourceLocation id, InputMethod<?> inputMethod);
+    
+    @Nullable
+    InputMethod<?> get(@Nullable ResourceLocation id);
+    
+    InputMethod<?> getOrDefault(@Nullable ResourceLocation id);
+    
+    Map<ResourceLocation, InputMethod<?>> getAll();
+}
diff --git a/api/src/main/java/me/shedaniel/rei/api/common/entry/EntryIngredient.java b/api/src/main/java/me/shedaniel/rei/api/common/entry/EntryIngredient.java
index ae9925788..fd6302218 100644
--- a/api/src/main/java/me/shedaniel/rei/api/common/entry/EntryIngredient.java
+++ b/api/src/main/java/me/shedaniel/rei/api/common/entry/EntryIngredient.java
@@ -31,7 +31,6 @@ import org.jetbrains.annotations.ApiStatus;
 
 import java.util.List;
 import java.util.function.Predicate;
-import java.util.function.Supplier;
 import java.util.function.UnaryOperator;
 import java.util.stream.Collector;
 import java.util.stream.Collectors;
diff --git a/api/src/main/java/me/shedaniel/rei/api/common/entry/EntryStack.java b/api/src/main/java/me/shedaniel/rei/api/common/entry/EntryStack.java
index 55864b952..580f8bc10 100644
--- a/api/src/main/java/me/shedaniel/rei/api/common/entry/EntryStack.java
+++ b/api/src/main/java/me/shedaniel/rei/api/common/entry/EntryStack.java
@@ -25,7 +25,6 @@ package me.shedaniel.rei.api.common.entry;
 
 import dev.architectury.utils.Env;
 import dev.architectury.utils.EnvExecutor;
-import me.shedaniel.math.Point;
 import me.shedaniel.rei.api.client.config.ConfigObject;
 import me.shedaniel.rei.api.client.entry.renderer.EntryRenderer;
 import me.shedaniel.rei.api.client.entry.renderer.EntryRendererRegistry;
@@ -50,7 +49,10 @@ import net.minecraft.world.item.ItemStack;
 import org.jetbrains.annotations.ApiStatus;
 import org.jetbrains.annotations.Nullable;
 
-import java.util.*;
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.Collections;
+import java.util.List;
 import java.util.function.BiFunction;
 import java.util.function.Function;
 import java.util.stream.Stream;
diff --git a/api/src/main/java/me/shedaniel/rei/api/common/entry/settings/EntrySettingsAdapter.java b/api/src/main/java/me/shedaniel/rei/api/common/entry/settings/EntrySettingsAdapter.java
index 6a8506197..dc8ae19ed 100644
--- a/api/src/main/java/me/shedaniel/rei/api/common/entry/settings/EntrySettingsAdapter.java
+++ b/api/src/main/java/me/shedaniel/rei/api/common/entry/settings/EntrySettingsAdapter.java
@@ -24,8 +24,6 @@
 package me.shedaniel.rei.api.common.entry.settings;
 
 import me.shedaniel.rei.api.common.entry.EntryStack;
-import net.fabricmc.api.EnvType;
-import net.fabricmc.api.Environment;
 import org.jetbrains.annotations.ApiStatus;
 import org.jetbrains.annotations.Nullable;
 
diff --git a/api/src/main/java/me/shedaniel/rei/api/common/util/CollectionUtils.java b/api/src/main/java/me/shedaniel/rei/api/common/util/CollectionUtils.java
index 3c05132c6..d657e0c4e 100644
--- a/api/src/main/java/me/shedaniel/rei/api/common/util/CollectionUtils.java
+++ b/api/src/main/java/me/shedaniel/rei/api/common/util/CollectionUtils.java
@@ -421,4 +421,41 @@ public class CollectionUtils {
     public static Ingredient toIngredient(Iterable<ItemStack> stacks) {
         return Ingredient.of(StreamSupport.stream(stacks.spliterator(), false));
     }
+    
+    @SafeVarargs
+    public static <T> List<T> concatUnmodifiable(List<? extends T>... lists) {
+        return new ListConcatenationView<>(lists);
+    }
+    
+    /**
+     * A list which acts as view of the concatenation of a number of lists.
+     */
+    private static class ListConcatenationView<E> extends AbstractList<E> {
+        private final List<? extends E>[] lists;
+        
+        @SafeVarargs
+        public ListConcatenationView(List<? extends E>... lists) {
+            this.lists = lists;
+        }
+        
+        @Override
+        public E get(int ix) {
+            int localIx = ix;
+            for (List<? extends E> l : lists) {
+                if (localIx < 0) throw new IndexOutOfBoundsException(ix);
+                if (localIx < l.size()) return l.get(localIx);
+                localIx -= l.size();
+            }
+            return null;
+        }
+        
+        @Override
+        public int size() {
+            int size = 0;
+            for (List<? extends E> l : lists) {
+                size += l.size();
+            }
+            return size;
+        }
+    }
 }