better inventory and nbt support. control flow statements default to nulls

src/main/java/carpet/script/value/BlockValue.java

@@ -6,10 +6,12 @@ import carpet.script.exception.InternalExpressionException;
 import com.mojang.brigadier.StringReader;
 import com.mojang.brigadier.exceptions.CommandSyntaxException;
 import net.minecraft.block.BlockState;
+import net.minecraft.block.entity.BlockEntity;
 import net.minecraft.command.arguments.BlockArgumentParser;
 import net.minecraft.block.Blocks;
 import net.minecraft.item.ItemPlacementContext;
 import net.minecraft.item.ItemStack;
+import net.minecraft.nbt.CompoundTag;
 import net.minecraft.util.Hand;
 import net.minecraft.util.hit.BlockHitResult;
 import net.minecraft.util.math.BlockPos;
@@ -31,6 +33,7 @@ public class BlockValue extends Value
     private BlockState blockState;
     private BlockPos pos;
     private World world;
+    private CompoundTag data;
 
     public static BlockValue fromCoords(CarpetContext c, int x, int y, int z)
     {
@@ -48,7 +51,10 @@ public class BlockValue extends Value
             BlockArgumentParser blockstateparser = (new BlockArgumentParser(new StringReader(str), false)).parse(true);
             if (blockstateparser.getBlockState() != null)
             {
-                bv = new BlockValue(blockstateparser.getBlockState(), null, null);
+                CompoundTag bd = blockstateparser.getNbtData();
+                if (bd == null)
+                    bd = new CompoundTag();
+                bv = new BlockValue(blockstateparser.getBlockState(), null, null, bd );
                 if (bvCache.size()>10000)
                     bvCache.clear();
                 bvCache.put(str, bv);
@@ -182,11 +188,44 @@ public class BlockValue extends Value
         throw new InternalExpressionException("Attemted to fetch blockstate without world or stored blockstate");
     }
 
+    public CompoundTag getData()
+    {
+        if (data != null)
+        {
+            if (data.isEmpty())
+                return null;
+            return data;
+        }
+        if (world != null && pos != null)
+        {
+            BlockEntity be = world.getBlockEntity(pos);
+            CompoundTag tag = new CompoundTag();
+            if (be == null)
+            {
+                data = tag;
+                return null;
+            }
+            data = be.toTag(tag);
+            return data;
+        }
+        throw new InternalExpressionException("Attemted to fetch block data without world or stored block data");
+    }
+
+
     public BlockValue(BlockState state, World world, BlockPos position)
     {
         this.world = world;
         blockState = state;
         pos = position;
+        data = null;
+    }
+
+    public BlockValue(BlockState state, World world, BlockPos position, CompoundTag nbt)
+    {
+        this.world = world;
+        blockState = state;
+        pos = position;
+        data = nbt;
     }
 
 

src/main/java/carpet/script/value/LazyListValue.java

@@ -100,4 +100,10 @@ public abstract class LazyListValue extends ListValue implements Iterator<Value>
         throw new InternalExpressionException("Cannot add to iterators");
     }
 
+    @Override
+    public boolean equals(final Value o)
+    {
+        return false;
+    }
+
 }

src/main/java/carpet/script/value/ListValue.java

@@ -203,25 +203,33 @@ public class ListValue extends Value
             ListValue ol = (ListValue)o;
             int this_size = this.getItems().size();
             int o_size = ol.getItems().size();
-            if (this_size != o_size)
-            {
-                return this_size - o_size;
-            }
-            if (this_size == 0)
-            {
-                return 0;
-            }
+            if (this_size != o_size) return this_size - o_size;
+            if (this_size == 0) return 0;
             for (int i = 0; i < this_size; i++)
             {
                 int res = this.items.get(i).compareTo(ol.items.get(i));
-                if (res != 0)
-                {
-                    return res;
-                }
+                if (res != 0) return res;
             }
             return 0;
         }
-        return super.compareTo(o);
+        return getString().compareTo(o.getString());
+    }
+
+    @Override
+    public boolean equals(final Value o)
+    {
+        if (o instanceof ListValue)
+        {
+            ListValue ol = (ListValue)o;
+            int this_size = this.getItems().size();
+            int o_size = ol.getItems().size();
+            if (this_size != o_size) return false;
+            if (this_size == 0) return true;
+            for (int i = 0; i < this_size; i++)
+                if (!this.items.get(i).equals(ol.items.get(i))) return false;
+            return true;
+        }
+        return false;
     }
 
     public List<Value> getItems()

src/main/java/carpet/script/value/NBTSerializableValue.java

@@ -7,17 +7,15 @@ import com.mojang.brigadier.StringReader;
 import com.mojang.brigadier.exceptions.CommandSyntaxException;
 import net.minecraft.block.entity.HopperBlockEntity;
 import net.minecraft.command.arguments.ItemStackArgument;
-import net.minecraft.command.arguments.ItemStackArgumentType;
 import net.minecraft.command.arguments.ItemStringReader;
 import net.minecraft.entity.Entity;
-import net.minecraft.entity.passive.AbstractTraderEntity;
 import net.minecraft.entity.passive.VillagerEntity;
 import net.minecraft.entity.player.PlayerEntity;
 import net.minecraft.inventory.Inventory;
 import net.minecraft.item.ItemStack;
 import net.minecraft.nbt.CompoundTag;
+import net.minecraft.nbt.StringNbtReader;
 import net.minecraft.util.math.BlockPos;
-import net.minecraft.util.math.MathHelper;
 
 import java.util.HashMap;
 import java.util.List;
@@ -26,15 +24,33 @@ import java.util.function.Supplier;
 
 public class NBTSerializableValue extends Value
 {
-    private Object what;
     private String nbtString = null;
     private CompoundTag nbtTag = null;
-    private Supplier<CompoundTag> nbtSupplier;
+    private Supplier<CompoundTag> nbtSupplier = null;
 
     public NBTSerializableValue(ItemStack stack)
     {
-        what = stack;
-        nbtSupplier = () -> ((ItemStack) what).toTag(new CompoundTag());
+        nbtSupplier = () -> stack.hasTag() ? stack.getTag(): new CompoundTag();
+    }
+
+    public NBTSerializableValue(String nbtString)
+    {
+        nbtSupplier = () ->
+        {
+            try
+            {
+                return (new StringNbtReader(new StringReader(nbtString))).parseCompoundTag();
+            }
+            catch (CommandSyntaxException e)
+            {
+                throw new InternalExpressionException("Incorrect nbt data: "+nbtString);
+            }
+        };
+    }
+
+    public NBTSerializableValue(CompoundTag tag)
+    {
+        nbtTag = tag;
     }
 
     public static InventoryLocator locateInventory(CarpetContext c, List<LazyValue> params, int offset)
@@ -93,19 +109,32 @@ public class NBTSerializableValue extends Value
     }
 
     private static Map<String,ItemStackArgument> itemCache = new HashMap<>();
+
     public static ItemStackArgument parseItem(String itemString)
+    {
+        return parseItem(itemString, null);
+    }
+
+    public static ItemStackArgument parseItem(String itemString, CompoundTag customTag)
     {
         try
         {
             ItemStackArgument res = itemCache.get(itemString);
             if (res != null)
-                return res;
+                if (customTag == null)
+                    return res;
+                else
+                    return new ItemStackArgument(res.getItem(), customTag);
+
             ItemStringReader parser = (new ItemStringReader(new StringReader(itemString), false)).consume();
             res = new ItemStackArgument(parser.getItem(), parser.getTag());
             itemCache.put(itemString, res);
             if (itemCache.size()>64000)
                 itemCache.clear();
-            return res;
+            if (customTag == null)
+                return res;
+            else
+                return new ItemStackArgument(res.getItem(), customTag);
         }
         catch (CommandSyntaxException e)
         {
@@ -123,13 +152,23 @@ public class NBTSerializableValue extends Value
         return slot;
     }
 
-    private CompoundTag getTag()
+    public CompoundTag getTag()
     {
         if (nbtTag == null)
             nbtTag = nbtSupplier.get();
         return nbtTag;
     }
 
+    @Override
+    public boolean equals(final Value o)
+    {
+        if (o instanceof NBTSerializableValue)
+        {
+            return getTag().equals(((NBTSerializableValue) o).getTag());
+        }
+        return super.equals(o);
+    }
+
 
     @Override
     public String getString()

src/main/java/carpet/script/value/NumericValue.java

@@ -116,7 +116,7 @@ public class NumericValue extends Value
         {
             return value.compareTo(((NumericValue) o).getDouble());
         }
-        return super.compareTo(o);
+        return getString().compareTo(o.getString());
     }
     @Override
     public boolean equals(Value o)