Add -e/-b/-m flags to //stack and //move, to match copy and paste.

Fixes WORLDEDIT-3935.

worldedit-core/src/main/java/com/sk89q/worldedit/function/biome/BiomeReplace.java

@@ -24,6 +24,7 @@ import static com.google.common.base.Preconditions.checkNotNull;
 import com.sk89q.worldedit.WorldEditException;
 import com.sk89q.worldedit.extent.Extent;
 import com.sk89q.worldedit.function.FlatRegionFunction;
+import com.sk89q.worldedit.function.pattern.BiomePattern;
 import com.sk89q.worldedit.math.BlockVector2;
 import com.sk89q.worldedit.world.biome.BiomeType;
 
@@ -33,7 +34,7 @@ import com.sk89q.worldedit.world.biome.BiomeType;
 public class BiomeReplace implements FlatRegionFunction {
 
     private final Extent extent;
-    private BiomeType biome;
+    private BiomePattern biome;
 
     /**
      * Create a new instance.
@@ -42,15 +43,25 @@ public class BiomeReplace implements FlatRegionFunction {
      * @param biome a biome
      */
     public BiomeReplace(Extent extent, BiomeType biome) {
+        this(extent, (BiomePattern) biome);
+    }
+
+    /**
+     * Create a new instance.
+     *
+     * @param extent the extent to apply this function to
+     * @param pattern the biome pattern to set
+     */
+    public BiomeReplace(Extent extent, BiomePattern pattern) {
         checkNotNull(extent);
-        checkNotNull(biome);
+        checkNotNull(pattern);
         this.extent = extent;
-        this.biome = biome;
+        this.biome = pattern;
     }
 
     @Override
     public boolean apply(BlockVector2 position) throws WorldEditException {
-        return extent.setBiome(position, biome);
+        return extent.setBiome(position, biome.apply(position));
     }
 
 }

worldedit-core/src/main/java/com/sk89q/worldedit/function/pattern/BiomePattern.java

@@ -0,0 +1,37 @@
+/*
+ * 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.pattern;
+
+import com.sk89q.worldedit.math.BlockVector2;
+import com.sk89q.worldedit.world.biome.BiomeType;
+
+/**
+ * Returns a {@link BiomeType} for a given position.
+ */
+public interface BiomePattern {
+
+    /**
+     * Return a {@link BiomeType} for the given position.
+     *
+     * @param position the position
+     * @return a block
+     */
+    BiomeType apply(BlockVector2 position);
+}