make run_step_by_step return only state

python/hyperon/runner.py

@@ -204,16 +204,12 @@ def process_results(self, results, flat=False):
         else:
             return [[Atom._from_catom(catom) for catom in result] for result in results]
 
-    def run_step_by_step(self, program, flat=False):
-        """Runs program step by step, yielding state and result"""
+    def run_step_by_step(self, program):
+        """Runs program step by step, yielding state"""
         state = RunnerState(self, program)
-        state.run_step()
-        results = state.current_results(flat=flat)
-        yield state, results
         while not state.is_complete():
             state.run_step()
-            results = state.current_results(flat=flat)
-            yield state, results
+            yield state
 
 
 class Environment:
@@ -251,4 +247,4 @@ def custom_env(working_dir = None, config_dir = None, create_config = False, dis
             hp.env_builder_set_is_test(True)
         for path in reversed(include_paths):
             hp.env_builder_add_include_path(builder, path)
-        return builder
+        return builder

python/tests/test_run_metta.py

@@ -78,11 +78,12 @@ def test_run_step_by_step(self):
         '''
         runner = MeTTa(env_builder=Environment.test_env())
         i = 0
-        for _state, results in runner.run_step_by_step(program):
+        for state in runner.run_step_by_step(program):
             pass
             i += 1
         print('number of steps ' + str(i))
         self.assertLess(i, 600)
+        results = state.current_results()
         self.assertEqual(len(results[0]), 2)
 
     def process_exceptions(self, results):