tracking and tracing

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

@@ -241,6 +241,12 @@ public class BlockValue extends Value
         return this != NULL && !getBlockState().isAir();
     }
 
+    @Override
+    public String getTypeString()
+    {
+        return "block";
+    }
+
     @Override
     public Value clone()
     {

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

@@ -1,6 +1,7 @@
 package carpet.script.value;
 
 import carpet.fakes.MobEntityInterface;
+import carpet.helpers.Tracer;
 import carpet.script.exception.InternalExpressionException;
 import com.mojang.brigadier.StringReader;
 import com.mojang.brigadier.exceptions.CommandSyntaxException;
@@ -30,6 +31,9 @@ import net.minecraft.server.network.ServerPlayerEntity;
 import net.minecraft.server.world.ServerWorld;
 import net.minecraft.text.LiteralText;
 import net.minecraft.util.Identifier;
+import net.minecraft.util.hit.BlockHitResult;
+import net.minecraft.util.hit.EntityHitResult;
+import net.minecraft.util.hit.HitResult;
 import net.minecraft.util.math.BlockPos;
 import net.minecraft.util.math.Direction;
 import net.minecraft.util.math.Vec3d;
@@ -124,6 +128,12 @@ public class EntityValue extends Value
         return this.get(what, null);
     }
 
+    @Override
+    public String getTypeString()
+    {
+        return "entity";
+    }
+
     public static Pair<EntityType<?>, Predicate<? super Entity>> getPredicate(String who)
     {
         Pair<EntityType<?>, Predicate<? super Entity>> res = entityPredicates.get(who);
@@ -310,20 +320,65 @@ public class EntityValue extends Value
             return new StringValue(Direction.getEntityFacingOrder(e)[index].asString());
         });
 
+        put("trace", (e, a) ->
+        {
+            float reach = 4.5f;
+            boolean entities = true;
+            boolean liquids = false;
+
+            if (a!=null)
+            {
+                if (!(a instanceof ListValue))
+                {
+                    reach = (float) NumericValue.asNumber(a).getDouble();
+                }
+                else
+                {
+                    List<Value> args = ((ListValue) a).getItems();
+                    if (args.size()==0)
+                        throw new InternalExpressionException("trace needs more arguments");
+                    reach = (float) NumericValue.asNumber(args.get(0)).getDouble();
+                    if (args.size() > 1)
+                    {
+                        entities = false;
+                        for (int i = 1; i < args.size(); i++)
+                        {
+                            String what = args.get(i).getString();
+                            if (what.equalsIgnoreCase("entities"))
+                                entities = true;
+                            else if (what.equalsIgnoreCase("blocks")) {}
+                            else if (what.equalsIgnoreCase("liquids"))
+                                liquids = true;
+                            else throw new InternalExpressionException("Incorrect tracing: "+what);
+                        }
+                    }
+                }
+            }
+            else if (e instanceof ServerPlayerEntity && ((ServerPlayerEntity) e).interactionManager.isCreative())
+            {
+                reach = 5.0f;
+            }
+
+            HitResult hitres;
+            if (entities)
+                hitres = Tracer.rayTrace(e, 1, reach, liquids);
+            else
+                hitres = Tracer.rayTraceBlocks(e, 1, reach, liquids);
+
+            switch (hitres.getType())
+            {
+                case MISS: return Value.NULL;
+                case BLOCK: return new BlockValue(null, e.getEntityWorld(), ((BlockHitResult)hitres).getBlockPos() );
+                case ENTITY: return new EntityValue(((EntityHitResult)hitres).getEntity());
+            }
+            return Value.NULL;
+        });
+
         put("nbt",(e, a) -> {
             CompoundTag nbttagcompound = e.toTag((new CompoundTag()));
             if (a==null)
                 return new NBTSerializableValue(nbttagcompound);//StringValue(nbttagcompound.toString());
-            NbtPathArgumentType.NbtPath path;
-            try
-            {
-                path = NbtPathArgumentType.nbtPath().method_9362(new StringReader(a.getString()));
-            }
-            catch (CommandSyntaxException exc)
-            {
-                throw new InternalExpressionException("Incorrect path: "+a.getString());
-            }
-            String res = null;
+            NbtPathArgumentType.NbtPath path = NBTSerializableValue.cachePath(a.getString());
             try
             {
                 List<Tag> tags = path.get(nbttagcompound);
@@ -331,7 +386,7 @@ public class EntityValue extends Value
                     return Value.NULL;
                 if (tags.size()==1)
                     return NBTSerializableValue.decodeTag(tags.get(0));
-                return ListValue.wrap(tags.stream().map(t -> NBTSerializableValue.decodeTag(t)).collect(Collectors.toList()));
+                return ListValue.wrap(tags.stream().map(NBTSerializableValue::decodeTag).collect(Collectors.toList()));
             }
             catch (CommandSyntaxException ignored) { }
             return Value.NULL;
@@ -504,9 +559,13 @@ public class EntityValue extends Value
 
         });
         put("custom_name", (e, v) -> {
-            String name = v.getString();
-            if (name.isEmpty())
+            if (v instanceof NullValue)
+            {
+                e.setCustomNameVisible(false);
                 e.setCustomName(null);
+                return;
+            }
+            e.setCustomNameVisible(true);
             e.setCustomName(new LiteralText(v.getString()));
         });
         put("dismount", (e, v) -> e.stopRiding() );

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

@@ -1,7 +1,7 @@
 package carpet.script.value;
 
 import carpet.script.exception.ExpressionException;
-import carpet.script.value.Value;
+import carpet.script.exception.InternalExpressionException;
 
 import java.util.List;
 
@@ -23,6 +23,12 @@ public class FunctionSignatureValue extends Value
         throw new ExpressionException("Function "+identifier+" is not defined yet");
     }
 
+    @Override
+    public String getTypeString()
+    {
+        throw new InternalExpressionException("How did you get here? Cannot get type of an internal struct.");
+    }
+
     @Override
     public Value clone()
     {

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

@@ -1,6 +1,6 @@
 package carpet.script.value;
 
-import carpet.script.value.Value;
+import carpet.script.exception.InternalExpressionException;
 
 public class GlobalValue extends Value
 {
@@ -21,4 +21,10 @@ public class GlobalValue extends Value
     {
         return false;
     }
+
+    @Override
+    public String getTypeString()
+    {
+        throw new InternalExpressionException("How did you get here? Cannot get type of an internal struct.");
+    }
 }

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

@@ -111,5 +111,10 @@ public abstract class LazyListValue extends ListValue implements Iterator<Value>
     {
         throw new InternalExpressionException("get element can only be obtained for regular lists");
     }
+    @Override
+    public String getTypeString()
+    {
+        return "iterator";
+    }
 
 }

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

@@ -326,6 +326,11 @@ public class ListValue extends Value
         index = index % numitems;
         return items.get((int)index);
     }
+    @Override
+    public String getTypeString()
+    {
+        return "list";
+    }
 
 
 

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

@@ -26,8 +26,6 @@ import java.util.Map;
 import java.util.function.Supplier;
 import java.util.stream.Collectors;
 
-import static java.lang.Math.abs;
-
 public class NBTSerializableValue extends Value
 {
     private String nbtString = null;
@@ -224,31 +222,38 @@ public class NBTSerializableValue extends Value
         }
     }
 
-    @Override
-    public Value getElementAt(Value value)
+    private static Map<String, NbtPathArgumentType.NbtPath> pathCache = new HashMap<>();
+    public static NbtPathArgumentType.NbtPath cachePath(String arg)
     {
-        String pathString = value.getString();
-
-        //return Value.NULL;
-
-        NbtPathArgumentType.NbtPath path;
+        NbtPathArgumentType.NbtPath res = pathCache.get(arg);
+        if (res != null)
+            return res;
         try
         {
-            path = NbtPathArgumentType.nbtPath().method_9362(new StringReader(pathString));
+            res = NbtPathArgumentType.nbtPath().method_9362(new StringReader(arg));
         }
         catch (CommandSyntaxException exc)
         {
-            throw new InternalExpressionException("Incorrect nbt path: "+pathString);
+            throw new InternalExpressionException("Incorrect nbt path: "+arg);
         }
-        String res = null;
+        if (pathCache.size() > 1024)
+            pathCache.clear();
+        pathCache.put(arg, res);
+        return res;
+    }
+
+    @Override
+    public Value getElementAt(Value value)
+    {
+        NbtPathArgumentType.NbtPath path = cachePath(value.getString());
         try
         {
             List<Tag> tags = path.get(getTag());
             if (tags.size()==0)
                 return Value.NULL;
             if (tags.size()==1)
-                return new NBTSerializableValue(tags.get(0));
-            return ListValue.wrap(tags.stream().map(NBTSerializableValue::new).collect(Collectors.toList()));
+                return NBTSerializableValue.decodeTag(tags.get(0));
+            return ListValue.wrap(tags.stream().map(NBTSerializableValue::decodeTag).collect(Collectors.toList()));
         }
         catch (CommandSyntaxException ignored) { }
         return Value.NULL;
@@ -259,4 +264,10 @@ public class NBTSerializableValue extends Value
         index = index % numitems;
         return items.get((int)index); */
     }
+
+    @Override
+    public String getTypeString()
+    {
+        return "nbt";
+    }
 }

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

@@ -38,4 +38,10 @@ public class NullValue extends NumericValue // TODO check nonsingleton code
     {
         return  o instanceof NullValue ? 0 : -1;
     }
+
+    @Override
+    public String getTypeString()
+    {
+        return "null";
+    }
 }

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

@@ -167,4 +167,10 @@ public class NumericValue extends Value
         return getLong();
     }
 
+    @Override
+    public String getTypeString()
+    {
+        return "number";
+    }
+
 }

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

@@ -24,4 +24,10 @@ public class StringValue extends Value
     {
         this.str = str;
     }
+
+    @Override
+    public String getTypeString()
+    {
+        return "number";
+    }
 }

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

@@ -177,4 +177,6 @@ public abstract class Value implements Comparable<Value>, Cloneable
     {
         throw new InternalExpressionException("get element can only be obtained for lists and nbt values");
     }
+
+    public abstract String getTypeString();
 }