remove instanceof NullValues fixes #1313

src/main/java/carpet/script/api/Auxiliary.java

@@ -361,7 +361,7 @@ public class Auxiliary {
             try
             {
                 Value nameValue = lv.get(0);
-                name = nameValue instanceof NullValue ? "" : nameValue.getString();
+                name = nameValue.isNull() ? "" : nameValue.getString();
                 pointLocator = Vector3Argument.findIn(lv, 1, true, false);
                 if (lv.size()>pointLocator.offset)
                 {

src/main/java/carpet/script/api/Inventories.java

@@ -248,7 +248,7 @@ public class Inventories {
                 Value nbtValue = lv.get(inventoryLocator.offset()+3);
                 if (nbtValue instanceof NBTSerializableValue)
                     nbt = ((NBTSerializableValue)nbtValue).getCompoundTag();
-                else if (nbtValue instanceof NullValue)
+                else if (nbtValue.isNull())
                     nbt = null;
                 else
                     nbt = new NBTSerializableValue(nbtValue.getString()).getCompoundTag();
@@ -277,7 +277,7 @@ public class Inventories {
             if (lv.size() > inventoryLocator.offset())
             {
                 Value secondArg = lv.get(inventoryLocator.offset()+0);
-                if (!(secondArg instanceof NullValue))
+                if (!secondArg.isNull())
                     itemArg = NBTSerializableValue.parseItem(secondArg.getString());
             }
             int startIndex = 0;

src/main/java/carpet/script/api/Scoreboards.java

@@ -231,7 +231,7 @@ public class Scoreboards {
             int slot = Scoreboard.getDisplaySlotByName(location);
             if (slot < 0) throw new InternalExpressionException("Invalid objective slot: "+location);
             Value target = lv.get(1);
-            if (target instanceof NullValue)
+            if (target.isNull())
             {
                 scoreboard.setDisplayObjective(slot, null);
                 return new NumericValue(slot);

src/main/java/carpet/script/api/WorldAccess.java

@@ -820,7 +820,7 @@ public class WorldAccess {
             {
                 if (!playerBreak) throw new InternalExpressionException("tag is not necessary with 'destroy' with no item");
                 Value tagValue = lv.get(locator.offset+1);
-                if (tagValue instanceof NullValue)
+                if (tagValue.isNull())
                     tag = null;
                 else if (tagValue instanceof NBTSerializableValue)
                     tag = ((NBTSerializableValue) tagValue).getCompoundTag();
@@ -1294,7 +1294,7 @@ public class WorldAccess {
             if (lv.size() > locator.offset)
             {
                 Value requested = lv.get(locator.offset+0);
-                if (!(requested instanceof NullValue))
+                if (!requested.isNull())
                 {
                     String reqString = requested.getString();
                     structure = Registry.STRUCTURE_FEATURE.getOptional(InputValidator.identifierOf(reqString))
@@ -1389,7 +1389,7 @@ public class WorldAccess {
                     return;
                 }
                 Value newValue = lv.get(locator.offset+1);
-                if (newValue instanceof NullValue) // remove structure
+                if (newValue.isNull()) // remove structure
                 {
                     StructureFeature<?> structure = configuredStructure.feature;
                     if (!structures.containsKey(structure))

src/main/java/carpet/script/argument/BlockArgument.java

@@ -51,7 +51,7 @@ public class BlockArgument extends Argument
         {
             Value v1 = params.next();
             //add conditional from string name
-            if (optional && v1 instanceof NullValue)
+            if (optional && v1.isNull())
             {
                 return new BlockArgument(null, 1 + offset);
             }
@@ -105,7 +105,7 @@ public class BlockArgument extends Argument
         {
             Value v1 = params.get(0 + offset);
             //add conditional from string name
-            if (optional && v1 instanceof NullValue)
+            if (optional && v1.isNull())
             {
                 return new BlockArgument(null, 1+offset);
             }

src/main/java/carpet/script/language/Sys.java

@@ -241,8 +241,8 @@ public class Sys {
 
             double result;
 
-            if (z instanceof NullValue)
-                if (y instanceof NullValue)
+            if (z.isNull())
+                if (y.isNull())
                     result = sampler.sample1d(NumericValue.asNumber(x).getDouble());
                 else
                     result = sampler.sample2d(NumericValue.asNumber(x).getDouble(), NumericValue.asNumber(y).getDouble());
@@ -279,7 +279,7 @@ public class Sys {
             }
             double result;
 
-            if (z instanceof NullValue)
+            if (z.isNull())
                 result = sampler.sample2d(NumericValue.asNumber(x).getDouble(), NumericValue.asNumber(y).getDouble());
             else
                 result = sampler.sample3d(

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

@@ -1231,7 +1231,7 @@ public class EntityValue extends Value
 
         });
         put("custom_name", (e, v) -> {
-            if (v instanceof NullValue)
+            if (v.isNull())
             {
                 e.setCustomNameVisible(false);
                 e.setCustomName(null);
@@ -1326,7 +1326,7 @@ public class EntityValue extends Value
             PathfinderMob ec = (PathfinderMob)e;
             if (v == null)
                 throw new InternalExpressionException("'home' requires at least one position argument, and optional distance, or null to cancel");
-            if (v instanceof NullValue)
+            if (v.isNull())
             {
                 ec.restrictTo(BlockPos.ZERO, -1);
                 Map<String,Goal> tasks = ((MobEntityInterface)ec).getTemporaryTasks();

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

@@ -24,7 +24,7 @@ public class FormattedTextValue extends StringValue
         }
         else
         {
-            if (left instanceof NullValue)
+            if (left.isNull())
                 return right;
             text = new TextComponent(left.getString());
         }
@@ -36,7 +36,7 @@ public class FormattedTextValue extends StringValue
         }
         else
         {
-            if (right instanceof NullValue)
+            if (right.isNull())
                 return left;
             text.append(right.getString());
             return new FormattedTextValue(text);

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

@@ -389,7 +389,7 @@ public class NBTSerializableValue extends Value implements ContainerValueInterfa
     {
         if (v instanceof NBTSerializableValue)
             return v;
-        if (v instanceof NullValue)
+        if (v.isNull())
             return Value.NULL;
         return NBTSerializableValue.parseString(v.getString(), true);
     }

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

@@ -37,7 +37,11 @@ public class NullValue extends NumericValue // TODO check nonsingleton code
     @Override
     public boolean equals(final Object o)
     {
-        return o instanceof NullValue;
+        if (o instanceof Value value)
+        {
+            return value.isNull();
+        }
+        return false;
     }
 
     @Override
@@ -58,7 +62,7 @@ public class NullValue extends NumericValue // TODO check nonsingleton code
     @Override
     public int compareTo(Value o)
     {
-        return  o instanceof NullValue ? 0 : -1;
+        return  o.isNull() ? 0 : -1;
     }
 
     @Override

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

@@ -172,7 +172,7 @@ public class NumericValue extends Value
     @Override
     public int compareTo(Value o)
     {
-        if (o instanceof NullValue)
+        if (o.isNull())
         {
             return -o.compareTo(this);
         }
@@ -187,17 +187,18 @@ public class NumericValue extends Value
     @Override
     public boolean equals(Object o)
     {
-        if (o instanceof NullValue)
-        {
-            return o.equals(this);
+        if (o instanceof Value value) {
+            if (value.isNull()) {
+                return o.equals(this);
+            }
+            if (o instanceof NumericValue no) {
+                if (longValue != null && no.longValue != null)
+                    return longValue.equals(no.longValue);
+                return !this.subtract(no).getBoolean();
+            }
+            return super.equals(o);
         }
-        if (o instanceof NumericValue no)
-        {
-            if (longValue != null && no.longValue != null)
-                return longValue.equals(no.longValue);
-            return !this.subtract(no).getBoolean();
-        }
-        return super.equals(o);
+        return false;
     }
 
     public NumericValue(double value)