Add a mask for block categories. Eg, you can now do //replace ##wool minecraft:sand to replace all wool with sand

worldedit-core/src/main/java/com/sk89q/worldedit/extension/factory/DefaultMaskParser.java

@@ -28,6 +28,7 @@ import com.sk89q.worldedit.extension.input.ParserContext;
 import com.sk89q.worldedit.extension.platform.Capability;
 import com.sk89q.worldedit.extent.Extent;
 import com.sk89q.worldedit.function.mask.BiomeMask2D;
+import com.sk89q.worldedit.function.mask.BlockCategoryMask;
 import com.sk89q.worldedit.function.mask.BlockMask;
 import com.sk89q.worldedit.function.mask.ExistingBlockMask;
 import com.sk89q.worldedit.function.mask.ExpressionMask;
@@ -47,6 +48,8 @@ import com.sk89q.worldedit.session.request.Request;
 import com.sk89q.worldedit.session.request.RequestSelection;
 import com.sk89q.worldedit.world.biome.BaseBiome;
 import com.sk89q.worldedit.world.biome.Biomes;
+import com.sk89q.worldedit.world.block.BlockCategories;
+import com.sk89q.worldedit.world.block.BlockCategory;
 import com.sk89q.worldedit.world.registry.BiomeRegistry;
 
 import java.util.ArrayList;
@@ -111,8 +114,16 @@ class DefaultMaskParser extends InputParser<Mask> {
                     } catch (IncompleteRegionException e) {
                         throw new InputParseException("Please make a selection first.");
                     }
+                } else if (component.startsWith("##")) {
+                    // This means it's a tag mask.
+                    BlockCategory category = BlockCategories.get(component.substring(2).toLowerCase());
+                    if (category == null) {
+                        throw new NoMatchException("Unrecognised tag '" + component.substring(2) + '\'');
+                    } else {
+                        return new BlockCategoryMask(extent, category);
+                    }
                 } else {
-                    throw new NoMatchException("Unrecognized mask '" + component + "'");
+                    throw new NoMatchException("Unrecognized mask '" + component + '\'');
                 }
 
             case '>':
@@ -135,7 +146,7 @@ class DefaultMaskParser extends InputParser<Mask> {
                 for (String biomeName : biomesList) {
                     BaseBiome biome = Biomes.findBiomeByName(knownBiomes, biomeName, biomeRegistry);
                     if (biome == null) {
-                        throw new InputParseException("Unknown biome '" + biomeName + "'");
+                        throw new InputParseException("Unknown biome '" + biomeName + '\'');
                     }
                     biomes.add(biome);
                 }

worldedit-core/src/main/java/com/sk89q/worldedit/function/mask/BlockCategoryMask.java

@@ -0,0 +1,53 @@
+/*
+ * WorldEdit, a Minecraft world manipulation toolkit
+ * Copyright (C) sk89q <http://www.sk89q.com>
+ * Copyright (C) WorldEdit team and contributors
+ *
+ * This program is free software: you can redistribute it and/or modify it
+ * under the terms of the GNU Lesser General Public License as published by the
+ * Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License
+ * for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+package com.sk89q.worldedit.function.mask;
+
+import static com.google.common.base.Preconditions.checkNotNull;
+
+import com.sk89q.worldedit.Vector;
+import com.sk89q.worldedit.extent.Extent;
+import com.sk89q.worldedit.world.block.BlockCategory;
+
+import javax.annotation.Nullable;
+
+/**
+ * A mask that tests whether a block matches a given {@link BlockCategory}, or tag.
+ */
+public class BlockCategoryMask extends AbstractExtentMask {
+
+    private BlockCategory category;
+
+    public BlockCategoryMask(Extent extent, BlockCategory category) {
+        super(extent);
+        checkNotNull(category);
+        this.category = category;
+    }
+
+    @Override
+    public boolean test(Vector vector) {
+        return category.contains(getExtent().getBlock(vector));
+    }
+
+    @Nullable
+    @Override
+    public Mask2D toMask2D() {
+        return null;
+    }
+}