despawn timer for living entities

src/main/java/carpet/script/CarpetExpression.java

@@ -1612,6 +1612,8 @@ public class CarpetExpression
      * <p>Eye height of the entity.</p>
      * <h3><code>query(e,'age')</code></h3>
      * <p>Age, in ticks, of the entity, i.e. how long it existed.</p>
+     * <h3><code>query(e,'despawn_timer')</code></h3>
+     * <p>For living entities - the number of ticks they fall outside of immediate player presence.</p>
      * <h3><code>query(e,'item')</code></h3>
      * <p>The item triple (name, count, nbt) if its an item entity, <code>null</code> otherwise</p>
      * <h3><code>query(e,'count')</code></h3>
@@ -1707,8 +1709,10 @@ public class CarpetExpression
      * <h3><code>modify(e, 'accelerate', x, y, z), modify(e, 'accelerate', l(x, y, z) )</code></h3>
      * <p>Adds a vector to the motion vector. Most realistic way to apply a force to an entity.</p>
      * <h3><code>modify(e, 'custom_name'), modify(e, 'custom_name', name )</code></h3>
-     * <h3><code>modify(e,'pickup_delay')</code></h3>
+     * <h3><code>modify(e, 'pickup_delay')</code></h3>
      * <p>Sets a custom pickup delay if the entity argument is an item entity</p>
+     * <h3><code>modify(e, 'despawn_timer')</code></h3>
+     * <p>Sets a custom despawn timer value.</p>
      * <h3><code>modify(e, 'dismount')</code></h3>
      * <p>Dismounts riding entity.</p>
      * <h3><code>modify(e, 'mount', other)</code></h3>

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

@@ -225,6 +225,7 @@ public class EntityValue extends Value
         put("width", (e, a) -> new NumericValue(e.getDimensions(EntityPose.STANDING).width));
         put("eye_height", (e, a) -> new NumericValue(e.getEyeHeight(EntityPose.STANDING)));
         put("age", (e, a) -> new NumericValue(e.age));
+        put("despawn_timer", (e, a) -> e instanceof LivingEntity?new NumericValue(((LivingEntity) e).getDespawnCounter()):Value.NULL);
         put("item", (e, a) -> (e instanceof ItemEntity)?ListValue.fromItemStack(((ItemEntity) e).getStack()):Value.NULL);
         put("count", (e, a) -> (e instanceof ItemEntity)?new NumericValue(((ItemEntity) e).getStack().getCount()):Value.NULL);
         put("pickup_delay", (e, a) -> (e instanceof ItemEntity)?new NumericValue(((ItemEntityInterface) e).getPickupDelay()):Value.NULL);
@@ -732,6 +733,14 @@ public class EntityValue extends Value
             }
         });
 
+        put("despawn_timer", (e, v) ->
+        {
+            if (e instanceof LivingEntity)
+            {
+                ((LivingEntity) e).setDespawnCounter((int)NumericValue.asNumber(v).getLong());
+            }
+        });
+
         put("ai", (e, v) ->
         {
             if (e instanceof MobEntity)