Merge remote-tracking branch 'origin/6.x-1.17' into 7.x-1.18

# Conflicts:
#	api/src/main/java/me/shedaniel/rei/api/common/transfer/info/MenuInfo.java
#	gradle.properties
#	runtime/src/main/java/me/shedaniel/rei/impl/client/search/argument/type/TooltipArgumentType.java
#	runtime/src/main/java/me/shedaniel/rei/plugin/autocrafting/DefaultCategoryHandler.java

10 files changed, 315 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 13ba8edf5..4ab9afc7b 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
@@ -148,6 +148,9 @@ public interface ConfigObject {
     List<EntryStackProvider<?>> getFilteredStackProviders();
     
     @ApiStatus.Experimental
+    boolean shouldFilterDisplays();
+    
+    @ApiStatus.Experimental
     boolean shouldAsyncSearch();
     
     @ApiStatus.Experimental
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 370caa671..7f691dcfe 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
@@ -23,6 +23,7 @@
 
 package me.shedaniel.rei.api.client.gui.widgets;
 
+import dev.architectury.utils.Env;
 import dev.architectury.utils.EnvExecutor;
 import me.shedaniel.math.Point;
 import me.shedaniel.rei.api.client.REIRuntime;
@@ -130,7 +131,7 @@ public interface Tooltip {
     Tooltip withContextStack(EntryStack<?> stack);
     
     default void queue() {
-        EnvExecutor.runInEnv(EnvType.CLIENT, () -> () -> REIRuntime.getInstance().queueTooltip(this));
+        EnvExecutor.runInEnv(Env.CLIENT, () -> () -> REIRuntime.getInstance().queueTooltip(this));
     }
     
     @ApiStatus.NonExtendable
diff --git a/api/src/main/java/me/shedaniel/rei/api/client/registry/display/TransferDisplayCategory.java b/api/src/main/java/me/shedaniel/rei/api/client/registry/display/TransferDisplayCategory.java
index 5cc0fc459..00843f57a 100644
--- a/api/src/main/java/me/shedaniel/rei/api/client/registry/display/TransferDisplayCategory.java
+++ b/api/src/main/java/me/shedaniel/rei/api/client/registry/display/TransferDisplayCategory.java
@@ -35,6 +35,8 @@ import org.jetbrains.annotations.ApiStatus;
 import java.util.List;
 
 @Environment(EnvType.CLIENT)
+@Deprecated
+@ApiStatus.ScheduledForRemoval
 public interface TransferDisplayCategory<T extends Display> extends DisplayCategory<T> {
     @ApiStatus.OverrideOnly
     @ApiStatus.ScheduledForRemoval
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 9ec3a3a15..2d8a8ef83 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
@@ -23,7 +23,6 @@
 
 package me.shedaniel.rei.api.client.registry.transfer;
 
-import it.unimi.dsi.fastutil.ints.IntArrayList;
 import it.unimi.dsi.fastutil.ints.IntList;
 import me.shedaniel.rei.api.client.registry.display.TransferDisplayCategory;
 import me.shedaniel.rei.api.common.display.Display;
@@ -36,6 +35,7 @@ import net.minecraft.world.inventory.AbstractContainerMenu;
 import org.jetbrains.annotations.ApiStatus;
 import org.jetbrains.annotations.Nullable;
 
+import java.util.List;
 import java.util.function.Supplier;
 
 /**
@@ -63,6 +63,16 @@ public interface TransferHandler extends Comparable<TransferHandler> {
         return Double.compare(getPriority(), o.getPriority());
     }
     
+    @Environment(EnvType.CLIENT)
+    @Nullable
+    default TransferHandlerErrorRenderer provideErrorRenderer(Context context, Object data) {
+        if (data instanceof IntList) {
+            return TransferHandlerErrorRenderer.forRedSlots((IntList) data);
+        }
+        
+        return null;
+    }
+    
     @ApiStatus.NonExtendable
     interface Result {
         /**
@@ -86,7 +96,7 @@ public interface TransferHandler extends Comparable<TransferHandler> {
          * @param error The error itself
          */
         static Result createFailed(Component error) {
-            return new ResultImpl(error, new IntArrayList(), 0x67ff0000);
+            return new ResultImpl(error, 0x67ff0000);
         }
         
         /**
@@ -97,7 +107,7 @@ public interface TransferHandler extends Comparable<TransferHandler> {
          * @param color A special color for the button
          */
         static Result createFailedCustomButtonColor(Component error, int color) {
-            return new ResultImpl(error, new IntArrayList(), color);
+            return createFailed(error).color(color);
         }
         
         /**
@@ -107,7 +117,7 @@ public interface TransferHandler extends Comparable<TransferHandler> {
          * @param redSlots A list of slots to be marked as red. Will be passed to {@link TransferDisplayCategory}.
          */
         static Result createFailed(Component error, IntList redSlots) {
-            return new ResultImpl(error, redSlots, 0x67ff0000);
+            return createFailed(error).errorRenderer(redSlots);
         }
         
         /**
@@ -119,7 +129,7 @@ public interface TransferHandler extends Comparable<TransferHandler> {
          * @param redSlots A list of slots to be marked as red. Will be passed to {@link TransferDisplayCategory}.
          */
         static Result createFailedCustomButtonColor(Component error, IntList redSlots, int color) {
-            return new ResultImpl(error, redSlots, color);
+            return createFailed(error).errorRenderer(redSlots).color(color);
         }
         
         /**
@@ -138,13 +148,18 @@ public interface TransferHandler extends Comparable<TransferHandler> {
          * @return the color in which the button should be displayed in.
          */
         int getColor();
-    
+        
         /**
          * Sets the color in which the button should be displayed in.
          */
         Result color(int color);
         
         /**
+         * Sets the error data, to be passed to {@link TransferHandler#provideErrorRenderer(Context, Object)}.
+         */
+        Result errorRenderer(Object data);
+        
+        /**
          * @return whether this handler has successfully handled the transfer.
          */
         boolean isSuccessful();
@@ -173,10 +188,12 @@ public interface TransferHandler extends Comparable<TransferHandler> {
          */
         Component getError();
         
-        /**
-         * @return a list of slots to be marked as red. Will be passed to {@link TransferDisplayCategory}.
-         */
-        IntList getIntegers();
+        @Environment(EnvType.CLIENT)
+        @ApiStatus.Internal
+        TransferHandlerErrorRenderer getErrorRenderer(TransferHandler handler, Context context);
+        
+        @ApiStatus.Internal
+        void fillTooltip(List<Component> components);
     }
     
     @ApiStatus.NonExtendable
@@ -211,7 +228,7 @@ public interface TransferHandler extends Comparable<TransferHandler> {
     final class ResultImpl implements Result {
         private boolean successful, applicable, returningToScreen, blocking;
         private Component error;
-        private IntList integers = new IntArrayList();
+        private Object errorRenderer;
         private int color;
         
         private ResultImpl() {
@@ -227,12 +244,10 @@ public interface TransferHandler extends Comparable<TransferHandler> {
             this.applicable = applicable;
         }
         
-        public ResultImpl(Component error, IntList integers, int color) {
+        public ResultImpl(Component error, int color) {
             this.successful = false;
             this.applicable = true;
             this.error = error;
-            if (integers != null)
-                this.integers = integers;
             this.color = color;
         }
         
@@ -255,6 +270,12 @@ public interface TransferHandler extends Comparable<TransferHandler> {
         }
         
         @Override
+        public Result errorRenderer(Object data) {
+            this.errorRenderer = data;
+            return this;
+        }
+        
+        @Override
         public boolean isSuccessful() {
             return successful;
         }
@@ -280,8 +301,17 @@ public interface TransferHandler extends Comparable<TransferHandler> {
         }
         
         @Override
-        public IntList getIntegers() {
-            return integers;
+        @Environment(EnvType.CLIENT)
+        public TransferHandlerErrorRenderer getErrorRenderer(TransferHandler handler, Context context) {
+            if (errorRenderer == null) return null;
+            return handler.provideErrorRenderer(context, errorRenderer);
+        }
+        
+        @Override
+        public void fillTooltip(List<Component> components) {
+            if (!isSuccessful() && isApplicable()) {
+                components.add(getError());
+            }
         }
     }
     
diff --git a/api/src/main/java/me/shedaniel/rei/api/client/registry/transfer/TransferHandlerErrorRenderer.java b/api/src/main/java/me/shedaniel/rei/api/client/registry/transfer/TransferHandlerErrorRenderer.java
new file mode 100644
index 000000000..d9669d753
--- /dev/null
+++ b/api/src/main/java/me/shedaniel/rei/api/client/registry/transfer/TransferHandlerErrorRenderer.java
@@ -0,0 +1,54 @@
+/*
+ * This file is licensed under the MIT License, part of Roughly Enough Items.
+ * Copyright (c) 2018, 2019, 2020, 2021 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.registry.transfer;
+
+import com.mojang.blaze3d.vertex.PoseStack;
+import it.unimi.dsi.fastutil.ints.IntList;
+import me.shedaniel.math.Rectangle;
+import me.shedaniel.rei.api.client.gui.widgets.Widget;
+import me.shedaniel.rei.api.client.registry.category.CategoryRegistry;
+import me.shedaniel.rei.api.client.registry.display.DisplayCategory;
+import me.shedaniel.rei.api.client.registry.display.TransferDisplayCategory;
+import me.shedaniel.rei.api.common.display.Display;
+import org.jetbrains.annotations.ApiStatus;
+
+import java.util.List;
+import java.util.Objects;
+
+@ApiStatus.Experimental
+@FunctionalInterface
+public interface TransferHandlerErrorRenderer {
+    void render(PoseStack matrices, int mouseX, int mouseY, float delta, List<Widget> widgets, Rectangle bounds, Display display);
+    
+    @ApiStatus.Internal
+    static TransferHandlerErrorRenderer forRedSlots(IntList redSlots) {
+        return (matrices, mouseX, mouseY, delta, widgets, bounds, display) -> {
+            DisplayCategory<?> category = Objects.requireNonNull(CategoryRegistry.getInstance().get(display.getCategoryIdentifier()))
+                    .getCategory();
+            if (category instanceof TransferDisplayCategory) {
+                ((TransferDisplayCategory<Display>) category).renderRedSlots(matrices, widgets, bounds, display, redSlots);
+            }
+        };
+    }
+}
diff --git a/api/src/main/java/me/shedaniel/rei/api/common/display/Display.java b/api/src/main/java/me/shedaniel/rei/api/common/display/Display.java
index 1ee2515e3..8b2b2ee22 100644
--- a/api/src/main/java/me/shedaniel/rei/api/common/display/Display.java
+++ b/api/src/main/java/me/shedaniel/rei/api/common/display/Display.java
@@ -25,6 +25,8 @@ package me.shedaniel.rei.api.common.display;
 
 import me.shedaniel.rei.api.common.category.CategoryIdentifier;
 import me.shedaniel.rei.api.common.entry.EntryIngredient;
+import me.shedaniel.rei.api.common.transfer.info.MenuInfo;
+import me.shedaniel.rei.api.common.transfer.info.MenuSerializationContext;
 import me.shedaniel.rei.impl.display.DisplaySpec;
 import net.minecraft.resources.ResourceLocation;
 import org.jetbrains.annotations.ApiStatus;
@@ -47,6 +49,10 @@ public interface Display extends DisplaySpec {
      */
     List<EntryIngredient> getInputEntries();
     
+    default List<EntryIngredient> getInputEntries(MenuSerializationContext<?, ?, ?> context, MenuInfo<?, ?> info, boolean fill) {
+        return getInputEntries();
+    }
+    
     /**
      * @return a list of outputs
      */
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 74529de5c..da37a0432 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
@@ -52,6 +52,7 @@ import java.util.function.Function;
 /**
  * @see me.shedaniel.rei.api.common.util.EntryStacks
  */
+@ApiStatus.NonExtendable
 public interface EntryStack<T> extends TextRepresentable, Renderer {
     static EntryStack<Unit> empty() {
         return Internals.getEntryStackProvider().empty();
@@ -122,14 +123,54 @@ public interface EntryStack<T> extends TextRepresentable, Renderer {
     
     boolean isEmpty();
     
+    /**
+     * Returns a copy of this stack.
+     * The copied stack will retain the same settings applied, with a copied value.
+     *
+     * @return a copy for an entry
+     */
     EntryStack<T> copy();
     
+    /**
+     * Returns a copy of this stack.
+     * The copied stack will retain the value object, with no settings applied.
+     *
+     * @return a copy for an entry
+     */
     default EntryStack<T> rewrap() {
         return copy();
     }
     
+    /**
+     * Returns a copy of this stack.
+     * The copied stack will have no settings applied.
+     * <p>
+     * The new value should be functionally equivalent to the original value,
+     * but should have a normalized state.
+     * <p>
+     * For example, an {@link net.minecraft.world.item.ItemStack} should have its
+     * amount removed, but its tags kept.
+     *
+     * @return a copy for an entry
+     */
     EntryStack<T> normalize();
     
+    /**
+     * Returns a copy of this stack.
+     * The copied stack will have no settings applied.
+     * <p>
+     * The new value should be the bare minimum to match the original value.
+     * <p>
+     * For example, an {@link net.minecraft.world.item.ItemStack} should have its
+     * amount and tags removed.
+     *
+     * @return a copy for an entry
+     * @since 6.2
+     */
+    default EntryStack<T> wildcard() {
+        return normalize();
+    }
+    
     Collection<ResourceLocation> getTagsFor();
     
     @Deprecated
diff --git a/api/src/main/java/me/shedaniel/rei/api/common/entry/type/EntryDefinition.java b/api/src/main/java/me/shedaniel/rei/api/common/entry/type/EntryDefinition.java
index 81e2a93dd..343a3491c 100644
--- a/api/src/main/java/me/shedaniel/rei/api/common/entry/type/EntryDefinition.java
+++ b/api/src/main/java/me/shedaniel/rei/api/common/entry/type/EntryDefinition.java
@@ -46,22 +46,92 @@ import java.util.Collection;
  * @see EntryTypeRegistry
  */
 public interface EntryDefinition<T> {
+    /**
+     * Returns the type of the entry.
+     *
+     * @return the type of the entry
+     */
     Class<T> getValueType();
     
+    /**
+     * Returns the type of this definition. The type is also used for comparing the type of two definitions,
+     * as the definition does not guarantee object and reference equality.
+     *
+     * @return the type of this definition
+     */
     EntryType<T> getType();
     
+    /**
+     * Returns the renderer for this entry, this is used to render the entry, and provide tooltip.
+     * External plugins can extend this method using {@link me.shedaniel.rei.api.client.entry.renderer.EntryRendererRegistry}
+     * to provide custom renderers.
+     *
+     * @return the renderer for this entry
+     */
     @Environment(EnvType.CLIENT)
     EntryRenderer<T> getRenderer();
     
+    /**
+     * Returns the identifier for an entry, used in identifier search argument type,
+     * and appending the mod name to the tooltip.
+     *
+     * @param entry the entry
+     * @param value the value of the entry
+     * @return the identifier for an entry
+     */
     @Nullable
     ResourceLocation getIdentifier(EntryStack<T> entry, T value);
     
+    /**
+     * Returns whether the entry is empty, empty entries are not displayed,
+     * and are considered invalid.
+     * Empty entries will be treated equally to {@link EntryStack#empty()}.
+     *
+     * @param entry the entry
+     * @param value the value of the entry
+     * @return whether the entry is empty
+     */
     boolean isEmpty(EntryStack<T> entry, T value);
     
+    /**
+     * Returns a copy for an entry.
+     *
+     * @param entry the entry
+     * @param value the value of the entry
+     * @return a copy for an entry
+     */
     T copy(EntryStack<T> entry, T value);
     
+    /**
+     * Returns a normalized copy for an entry.
+     * The returned stack should be functionally equivalent to the original stack,
+     * but should have a normalized state.
+     * <p>
+     * For example, an {@link net.minecraft.world.item.ItemStack} should have its
+     * amount removed, but its tags kept.
+     *
+     * @param entry the entry
+     * @param value the value of the entry
+     * @return a normalized copy for an entry
+     */
     T normalize(EntryStack<T> entry, T value);
     
+    /**
+     * Returns a wildcard copy for an entry.
+     * The returned stack should be the bare minimum to match the original stack.
+     * <p>
+     * For example, an {@link net.minecraft.world.item.ItemStack} should have its
+     * amount and tags removed.
+     *
+     * @param entry the entry
+     * @param value the value of the entry
+     * @return a wildcard copy for an entry
+     * @since 6.2
+     */
+    default T wildcard(EntryStack<T> entry, T value) {
+        return normalize(entry, value);
+    }
+    
     long hash(EntryStack<T> entry, T value, ComparisonContext context);
     
     boolean equals(T o1, T o2, ComparisonContext context);
diff --git a/api/src/main/java/me/shedaniel/rei/api/common/transfer/info/MenuInfo.java b/api/src/main/java/me/shedaniel/rei/api/common/transfer/info/MenuInfo.java
index cde2c2231..7fe0e15a4 100644
--- a/api/src/main/java/me/shedaniel/rei/api/common/transfer/info/MenuInfo.java
+++ b/api/src/main/java/me/shedaniel/rei/api/common/transfer/info/MenuInfo.java
@@ -23,6 +23,12 @@
 
 package me.shedaniel.rei.api.common.transfer.info;
 
+import com.mojang.blaze3d.vertex.PoseStack;
+import it.unimi.dsi.fastutil.ints.IntList;
+import me.shedaniel.math.Rectangle;
+import me.shedaniel.rei.api.client.gui.widgets.Slot;
+import me.shedaniel.rei.api.client.gui.widgets.Widget;
+import me.shedaniel.rei.api.common.category.CategoryIdentifier;
 import me.shedaniel.rei.api.common.display.Display;
 import me.shedaniel.rei.api.common.display.DisplaySerializerRegistry;
 import me.shedaniel.rei.api.common.entry.EntryStack;
@@ -35,10 +41,12 @@ import me.shedaniel.rei.api.common.transfer.info.stack.SlotAccessor;
 import me.shedaniel.rei.api.common.util.CollectionUtils;
 import net.fabricmc.api.EnvType;
 import net.fabricmc.api.Environment;
+import net.minecraft.client.gui.GuiComponent;
 import net.minecraft.nbt.CompoundTag;
 import net.minecraft.server.level.ServerPlayer;
 import net.minecraft.world.inventory.AbstractContainerMenu;
 import net.minecraft.world.item.ItemStack;
+import org.jetbrains.annotations.ApiStatus;
 
 import java.util.Collections;
 import java.util.List;
@@ -112,16 +120,30 @@ public interface MenuInfo<T extends AbstractContainerMenu, D extends Display> {
      * Returns the inputs of the {@link Display}. The nested lists are possible stacks for that specific slot.
      *
      * @param context the context of the transfer
+     * @param fill    whether this call is for a fill or not, if it is for a fill, the returned list should be aligned for the menu,
+     *                otherwise it should be aligned for the display category
      * @return the list of lists of items
      */
-    default List<List<ItemStack>> getInputs(MenuInfoContext<T, ?, D> context) {
+    default List<List<ItemStack>> getInputs(MenuInfoContext<T, ?, D> context, boolean fill) {
         if (context.getDisplay() == null) return Collections.emptyList();
-        return CollectionUtils.map(context.getDisplay().getInputEntries(), inputEntry ->
+        return CollectionUtils.map(context.getDisplay().getInputEntries(context, this, fill), inputEntry ->
                 CollectionUtils.<EntryStack<?>, ItemStack>filterAndMap(inputEntry,
                         stack -> stack.getType() == VanillaEntryTypes.ITEM, EntryStack::castValue));
     }
     
     /**
+     * Returns the inputs of the {@link Display}. The nested lists are possible stacks for that specific slot.
+     *
+     * @param context the context of the transfer
+     * @return the list of lists of items
+     */
+    @Deprecated
+    @ApiStatus.ScheduledForRemoval
+    default List<List<ItemStack>> getInputs(MenuInfoContext<T, ?, D> context) {
+        return getInputs(context, false);
+    }
+    
+    /**
      * Serializes the {@link Display} as {@link CompoundTag}, sent to the server for further info for the transfer.
      *
      * @param context the context of the transfer
@@ -138,4 +160,35 @@ public interface MenuInfo<T extends AbstractContainerMenu, D extends Display> {
      * @return the {@link Display}
      */
     D getDisplay();
+    
+    /**
+     * Renders the missing ingredients of the transfer.
+     * The indices of the missing stacks are provided, this aligns with the list returned by {@link #getInputs(MenuInfoContext, boolean)}.
+     *
+     * @param context        the context of the transfer
+     * @param inputs         the list of inputs
+     * @param missingIndices the indices of the missing stacks
+     * @param matrices       the rendering transforming matrices
+     * @param mouseX         the mouse x position
+     * @param mouseY         the mouse y position
+     * @param delta          the delta frame time
+     * @param widgets        the widgets set-up by the category
+     * @param bounds         the bounds of the display
+     */
+    @Environment(EnvType.CLIENT)
+    default void renderMissingInput(MenuInfoContext<T, ?, D> context, List<List<ItemStack>> inputs, IntList missingIndices, PoseStack matrices, int mouseX, int mouseY,
+            float delta, List<Widget> widgets, Rectangle bounds) {
+        int i = 0;
+        for (Widget widget : widgets) {
+            if (widget instanceof Slot && ((Slot) widget).getNoticeMark() == Slot.INPUT) {
+                if (missingIndices.contains(i++)) {
+                    matrices.pushPose();
+                    matrices.translate(0, 0, 400);
+                    Rectangle innerBounds = ((Slot) widget).getInnerBounds();
+                    GuiComponent.fill(matrices, innerBounds.x, innerBounds.y, innerBounds.getMaxX(), innerBounds.getMaxY(), 0x40ff0000);
+                    matrices.popPose();
+                }
+            }
+        }
+    }
 }
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 aa4ac5037..946d9336f 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
@@ -265,6 +265,19 @@ public class CollectionUtils {
         return l == null ? Collections.emptyList() : l;
     }
     
+    public static <T, R> List<R> mapAndFilter(Iterable<T> list, Predicate<R> predicate, Function<T, R> function) {
+        List<R> l = null;
+        for (T t : list) {
+            R r = function.apply(t);
+            if (predicate.test(r)) {
+                if (l == null)
+                    l = Lists.newArrayList();
+                l.add(r);
+            }
+        }
+        return l == null ? Collections.emptyList() : l;
+    }
+    
     public static <T> int sumInt(Iterable<T> list, Function<T, Integer> function) {
         int sum = 0;
         for (T t : list) {
@@ -323,6 +336,29 @@ public class CollectionUtils {
                     public int size() {
                         return realSize;
                     }
+                    
+                    @Override
+                    public Iterator<T> iterator() {
+                        Iterator<T> iterator = super.iterator();
+                        return new Iterator<T>() {
+                            boolean endReached = false;
+                            
+                            @Override
+                            public boolean hasNext() {
+                                return iterator.hasNext() && !endReached;
+                            }
+                            
+                            @Override
+                            public T next() {
+                                try {
+                                    return iterator.next();
+                                } catch (NoSuchElementException e) {
+                                    endReached = true;
+                                    return null;
+                                }
+                            }
+                        };
+                    }
                 };
             }
         };