Fix regression in State.from_index

Likely caused by f69cda1b84482a2c5dd4c6b8fcf16aebb7ac11ba

1 files changed, 3 insertions, 4 deletions

diff --git a/mdpoly/state.py b/mdpoly/state.py
index 6924146..0095916 100644
--- a/mdpoly/state.py
+++ b/mdpoly/state.py
@@ -3,7 +3,7 @@ from typing import TYPE_CHECKING
 from dataclasses import dataclass, field
 
 from .index import PolyVarIndex
-from .abc import Var, Param, Const
+from .abc import Var, Param
 
 if TYPE_CHECKING:
     from .index import Number
@@ -35,7 +35,7 @@ class State:
 
         return self.variables[var]
 
-    def from_index(self, index: Index | PolyVarIndex) -> Var | Const:
+    def from_index(self, index: Index | PolyVarIndex) -> Var | Number:
         """ Get a variable object from the index.
         This is a reverse lookup operation and it is **not**
         :math:`\mathcal{O}(1)`!"""
@@ -43,8 +43,7 @@ class State:
             index = index.var_idx
 
         if index == -1:
-            from .leaves import Const
-            return Const(value=1, name="1")
+            return 1
 
         for var, idx in self.variables.items():
             if idx == index: