Implement autoplace (#6)

src/main/java/com/gtnewhorizon/structurelib/util/ItemStackArrayIterable.java

@@ -0,0 +1,38 @@
+package com.gtnewhorizon.structurelib.util;
+
+import java.util.Iterator;
+import net.minecraft.item.ItemStack;
+
+public class ItemStackArrayIterable implements Iterable<ItemStack> {
+    private final ItemStack[] stacks;
+
+    public ItemStackArrayIterable(ItemStack[] stacks) {
+        this.stacks = stacks;
+    }
+
+    public ItemStack[] getStacks() {
+        return stacks;
+    }
+
+    @Override
+    public Iterator<ItemStack> iterator() {
+        return new Iterator<ItemStack>() {
+            private int ptr = 0;
+
+            @Override
+            public boolean hasNext() {
+                return ptr < stacks.length;
+            }
+
+            @Override
+            public ItemStack next() {
+                return stacks[ptr++];
+            }
+
+            @Override
+            public void remove() {
+                stacks[ptr - 1] = null;
+            }
+        };
+    }
+}