Make HolderSet an interface

api/src/main/java/com/viaversion/viaversion/api/minecraft/HolderSet.java

@@ -22,18 +22,58 @@
  */
 package com.viaversion.viaversion.api.minecraft;
 
-import com.viaversion.viaversion.util.EitherImpl;
-
 /**
  * Set of ids that either holds a string tag key or an array of ids.
  */
-public final class HolderSet extends EitherImpl<String, int[]> {
+public interface HolderSet {
 
-    public HolderSet(final String tagKey) {
-        super(tagKey, null);
+    /**
+     * Creates a new holder set for the given tag.
+     *
+     * @param tagKey the tag key
+     * @return a new holder set
+     */
+    static HolderSet of(final String tagKey) {
+        return new HolderSetImpl(tagKey);
     }
 
-    public HolderSet(final int[] ids) {
-        super(null, ids);
+    /**
+     * Creates a new holder set for the given ids.
+     *
+     * @param ids the direct ids
+     * @return a new holder set
+     */
+    static HolderSet of(final int[] ids) {
+        return new HolderSetImpl(ids);
     }
+
+    /**
+     * Gets the tag key.
+     *
+     * @return the tag key
+     * @see #hasTagKey()
+     */
+    String tagKey();
+
+    /**
+     * Returns whether this holder set has a tag key.
+     *
+     * @return true if this holder set has a tag key, false if it has direct ids
+     */
+    boolean hasTagKey();
+
+    /**
+     * Gets the direct ids.
+     *
+     * @return direct ids
+     * @see #hasIds()
+     */
+    int[] ids();
+
+    /**
+     * Returns whether this holder set has direct ids.
+     *
+     * @return true if this holder set has direct ids, false if it has a tag key
+     */
+    boolean hasIds();
 }

api/src/main/java/com/viaversion/viaversion/api/minecraft/HolderSetImpl.java

@@ -0,0 +1,56 @@
+/*
+ * This file is part of ViaVersion - https://github.com/ViaVersion/ViaVersion
+ * Copyright (C) 2016-2024 ViaVersion and contributors
+ *
+ * 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 com.viaversion.viaversion.api.minecraft;
+
+import com.viaversion.viaversion.util.EitherImpl;
+
+final class HolderSetImpl extends EitherImpl<String, int[]> implements HolderSet {
+
+    HolderSetImpl(final String tagKey) {
+        super(tagKey, null);
+    }
+
+    HolderSetImpl(final int[] ids) {
+        super(null, ids);
+    }
+
+    @Override
+    public String tagKey() {
+        return left();
+    }
+
+    @Override
+    public boolean hasTagKey() {
+        return isLeft();
+    }
+
+    @Override
+    public int[] ids() {
+        return right();
+    }
+
+    @Override
+    public boolean hasIds() {
+        return isRight();
+    }
+}

api/src/main/java/com/viaversion/viaversion/api/minecraft/item/data/BlockPredicate.java

@@ -42,7 +42,7 @@ public final class BlockPredicate {
 
         @Override
         public void write(final ByteBuf buffer, final BlockPredicate value) throws Exception {
-            Type.OPTIONAL_HOLDER_SET.write(buffer, value.holders);
+            Type.OPTIONAL_HOLDER_SET.write(buffer, value.holderSet);
 
             buffer.writeBoolean(value.propertyMatchers != null);
             if (value.propertyMatchers != null) {
@@ -54,18 +54,18 @@ public final class BlockPredicate {
     };
     public static final Type<BlockPredicate[]> ARRAY_TYPE = new ArrayType<>(TYPE);
 
-    private final HolderSet holders;
+    private final HolderSet holderSet;
     private final StatePropertyMatcher[] propertyMatchers;
     private final CompoundTag tag;
 
-    public BlockPredicate(@Nullable final HolderSet holders, final StatePropertyMatcher @Nullable [] propertyMatchers, @Nullable final CompoundTag tag) {
-        this.holders = holders;
+    public BlockPredicate(@Nullable final HolderSet holderSet, final StatePropertyMatcher @Nullable [] propertyMatchers, @Nullable final CompoundTag tag) {
+        this.holderSet = holderSet;
         this.propertyMatchers = propertyMatchers;
         this.tag = tag;
     }
 
-    public @Nullable HolderSet predicates() {
-        return holders;
+    public @Nullable HolderSet holderSet() {
+        return holderSet;
     }
 
     public StatePropertyMatcher @Nullable [] propertyMatchers() {

api/src/main/java/com/viaversion/viaversion/api/type/types/misc/HolderSetType.java

@@ -38,23 +38,23 @@ public class HolderSetType extends Type<HolderSet> {
         final int size = Type.VAR_INT.readPrimitive(buffer) - 1;
         if (size == -1) {
             final String tag = Type.STRING.read(buffer);
-            return new HolderSet(tag);
+            return HolderSet.of(tag);
         }
 
         final int[] values = new int[size];
         for (int i = 0; i < size; i++) {
             values[i] = Type.VAR_INT.readPrimitive(buffer);
         }
-        return new HolderSet(values);
+        return HolderSet.of(values);
     }
 
     @Override
     public void write(final ByteBuf buffer, final HolderSet object) throws Exception {
-        if (object.isLeft()) {
+        if (object.hasTagKey()) {
             Type.VAR_INT.writePrimitive(buffer, 0);
-            Type.STRING.write(buffer, object.left());
+            Type.STRING.write(buffer, object.tagKey());
         } else {
-            final int[] values = object.right();
+            final int[] values = object.ids();
             Type.VAR_INT.writePrimitive(buffer, values.length + 1);
             for (final int value : values) {
                 Type.VAR_INT.writePrimitive(buffer, value);

common/src/main/java/com/viaversion/viaversion/protocols/protocol1_20_5to1_20_3/rewriter/BlockItemPacketRewriter1_20_5.java

@@ -452,9 +452,9 @@ public final class BlockItemPacketRewriter1_20_5 extends ItemRewriter<Clientboun
                 return null;
             }
 
-            holders = new HolderSet(new int[]{Protocol1_20_5To1_20_3.MAPPINGS.getNewBlockId(id)});
+            holders = HolderSet.of(new int[]{Protocol1_20_5To1_20_3.MAPPINGS.getNewBlockId(id)});
         } else {
-            holders = new HolderSet(identifier.substring(1));
+            holders = HolderSet.of(identifier.substring(1));
         }
 
         final int propertiesEndIndex = rawPredicate.indexOf(']');
@@ -468,7 +468,7 @@ public final class BlockItemPacketRewriter1_20_5 extends ItemRewriter<Clientboun
 
                 final String propertyId = property.substring(0, propertySplitIndex).trim();
                 final String propertyValue = property.substring(propertySplitIndex + 1).trim();
-                propertyMatchers.add(new StatePropertyMatcher(propertyId, Either.left(propertyValue))); // TODO Also handle ranged matchers
+                propertyMatchers.add(new StatePropertyMatcher(propertyId, Either.left(propertyValue)));
             }
         }
 

common/src/main/java/com/viaversion/viaversion/protocols/protocol1_20_5to1_20_3/rewriter/StructuredDataConverter.java

@@ -349,17 +349,16 @@ final class StructuredDataConverter {
     private static void convertBlockPredicates(final CompoundTag tag, final AdventureModePredicate data, final String key, final int hideFlag) {
         final ListTag<StringTag> predicatedListTag = new ListTag<>(StringTag.class);
         for (final BlockPredicate predicate : data.predicates()) {
-            final HolderSet holders = predicate.predicates();
+            final HolderSet holders = predicate.holderSet();
             if (holders == null) {
                 // Can't do (nicely)
                 continue;
             }
-
-            if (holders.isLeft()) {
-                final String identifier = holders.left();
-                predicatedListTag.add(serializeBlockPredicate(predicate, identifier));
+            if (holders.hasTagKey()) {
+                final String tagKey = "#" + holders.tagKey();
+                predicatedListTag.add(serializeBlockPredicate(predicate, tagKey));
             } else {
-                for (final int id : holders.right()) {
+                for (final int id : holders.ids()) {
                     final int oldId = Protocol1_20_5To1_20_3.MAPPINGS.getOldItemId(id);
                     final String identifier = Protocol1_20_5To1_20_3.MAPPINGS.itemName(oldId);
                     predicatedListTag.add(serializeBlockPredicate(predicate, identifier));
@@ -377,7 +376,7 @@ final class StructuredDataConverter {
         final StringBuilder builder = new StringBuilder(identifier);
         if (predicate.propertyMatchers() != null) {
             for (final StatePropertyMatcher matcher : predicate.propertyMatchers()) {
-                // I'm not sure if ranged values were possible in 1.20.4 (if so, there's no trace of how)
+                // Ranges were introduced in 1.20.5, so only handle the simple case
                 if (matcher.matcher().isLeft()) {
                     builder.append(matcher.name()).append('=');
                     builder.append(matcher.matcher().left());