remove iter attribute

Author: elebras1

src/main/java/com/github/elebras1/flecs/ObserverBuilder.java

@@ -16,7 +16,6 @@ public class ObserverBuilder {
     private Query.IterCallback iterCallback;
     private Query.RunCallback runCallback;
     private Query.EntityCallback entityCallback;
-    private Iter iter;
     private static final long TERM_SIZE = ecs_term_t.layout().byteSize();
     private static final int MAX_EVENTS = 8;
 
@@ -26,7 +25,6 @@ public ObserverBuilder(World world) {
         this.desc = ecs_observer_desc_t.allocate(this.arena);
         this.termCount = 0;
         this.eventCount = 0;
-        this.iter = null;
     }
 
     public ObserverBuilder(World world, String name) {
@@ -163,12 +161,8 @@ public FlecsObserver iter(Query.IterCallback callback) {
         this.iterCallback = callback;
 
         MemorySegment callbackStub = ecs_iter_action_t.allocate(it -> {
-            if (this.iter == null) {
-                this.iter = new Iter(it, this.world);
-            } else {
-                iter.setNativeIter(it);
-            }
-            callback.accept(this.iter);
+            Iter iter = new Iter(it, this.world);
+            callback.accept(iter);
         }, this.world.arena());
 
         ecs_observer_desc_t.callback(this.desc, callbackStub);
@@ -180,12 +174,8 @@ public FlecsObserver run(Query.RunCallback callback) {
         this.runCallback = callback;
 
         MemorySegment callbackStub = ecs_run_action_t.allocate(it -> {
-            if (this.iter == null) {
-                this.iter = new Iter(it, this.world);
-            } else {
-                iter.setNativeIter(it);
-            }
-            callback.accept(this.iter);
+            Iter iter = new Iter(it, this.world);
+            callback.accept(iter);
         }, this.world.arena());
 
         ecs_observer_desc_t.run(this.desc, callbackStub);

src/main/java/com/github/elebras1/flecs/SystemBuilder.java

@@ -17,7 +17,6 @@ public class SystemBuilder {
     private Query.RunCallback runCallback;
     private Query.EntityCallback entityCallback;
     private long phase = 0;
-    private Iter iter;
 
     public SystemBuilder(World world) {
         this.world = world;
@@ -201,16 +200,12 @@ public FlecsSystem run(Query.RunCallback callback) {
         this.runCallback = callback;
 
         MemorySegment callbackStub = ecs_run_action_t.allocate(it -> {
-            if (this.iter == null) {
-                this.iter = new Iter(it, this.world);
-            } else {
-                this.iter.setNativeIter(it);
-            }
-            callback.accept(this.iter);
+            Iter iter = new Iter(it, this.world);
+            callback.accept(iter);
         }, this.world.arena());
-        
+
         ecs_system_desc_t.run(this.desc, callbackStub);
-        
+
         return build();
     }
 

src/main/java/com/github/elebras1/flecs/TimerBuilder.java

@@ -1,18 +1,15 @@
 package com.github.elebras1.flecs;
 
-import java.lang.foreign.Arena;
 import java.lang.foreign.MemorySegment;
 
 public class TimerBuilder {
 
     private final World world;
-    private final Arena arena;
     private final MemorySegment desc;
 
     TimerBuilder(World world) {
         this.world = world;
-        this.arena = Arena.ofConfined();
-        this.desc = ecs_system_desc_t.allocate(this.arena);
+        this.desc = ecs_system_desc_t.allocate(this.world.arena());
     }
 
     public TimerBuilder interval(float interval) {