warning message for delete state function

stormvogel/model.py

@@ -92,7 +92,11 @@ def __init__(
         self.observation = None
 
         if name is None:
-            self.name = str(id)  # TODO Two states can have same name in some cases
+            if str(id) in used_names:
+                raise RuntimeError(
+                    "You need to choose a state name because of a conflict caused by removal of states."
+                )
+            self.name = str(id)
         else:
             self.name = name
 
@@ -769,9 +773,15 @@ def reassign_ids(self):
             }
 
     def remove_state(
-        self, state: State, normalize: bool = True, reassign_ids: bool = True
+        self, state: State, normalize: bool = True, reassign_ids: bool = False
     ):
-        """properly removes a state, it can optionally normalize the model and reassign ids automatically"""
+        """Properly removes a state, it can optionally normalize the model and reassign ids automatically."""
+
+        if reassign_ids:
+            print(
+                "Warning: Using this can cause problems in your code if there are existing references to states by id."
+            )
+
         if state in self.states.values():
             # we remove the state from the transitions
             # first we remove transitions that go into the state
@@ -885,16 +895,15 @@ def new_state(
         self,
         labels: list[str] | str | None = None,
         features: dict[str, int] | None = None,
-        name: str | None = None,
     ) -> State:
         """Creates a new state and returns it."""
         state_id = self.__free_state_id()
         if isinstance(labels, list):
-            state = State(labels, features or {}, state_id, self, name=name)
+            state = State(labels, features or {}, state_id, self)
         elif isinstance(labels, str):
-            state = State([labels], features or {}, state_id, self, name=name)
+            state = State([labels], features or {}, state_id, self)
         elif labels is None:
-            state = State([], features or {}, state_id, self, name=name)
+            state = State([], features or {}, state_id, self)
 
         self.states[state_id] = state
 

tests/test_model_methods.py

@@ -155,7 +155,7 @@ def test_normalize():
 def test_remove_state():
     # we make a normal ctmc and remove a state
     ctmc = examples.nuclear_fusion_ctmc.create_nuclear_fusion_ctmc()
-    ctmc.remove_state(ctmc.get_state_by_id(3))
+    ctmc.remove_state(ctmc.get_state_by_id(3), reassign_ids=True)
 
     # we make a ctmc with the state already missing
     new_ctmc = stormvogel.model.new_ctmc("Nuclear fusion")
@@ -193,7 +193,7 @@ def test_remove_state():
     mdp.set_transitions(mdp.get_initial_state(), transition)
 
     # we remove a state
-    mdp.remove_state(mdp.get_state_by_id(0))
+    mdp.remove_state(mdp.get_state_by_id(0), reassign_ids=True)
 
     # we make the mdp with the state already missing
     new_mdp = stormvogel.model.new_mdp(create_initial_state=False)
@@ -203,6 +203,14 @@ def test_remove_state():
 
     assert mdp == new_mdp
 
+    # this should fail:
+    new_dtmc = examples.die.create_die_dtmc()
+    state0 = new_dtmc.get_state_by_id(0)
+    new_dtmc.remove_state(new_dtmc.get_initial_state(), reassign_ids=True)
+    state1 = new_dtmc.get_state_by_id(0)
+
+    assert state0 != state1
+
 
 def test_remove_transitions_between_states():
     # we make a model and remove transitions between two states