Add RegisterLayout.static_hash()

pulser-core/pulser/register/register_layout.py

@@ -302,6 +302,22 @@ def _safe_hash(self) -> bytes:
         hash.update(self.coords.tobytes())
         return hash.digest()
 
+    def static_hash(self) -> str:
+        """Returns the layout's idempotent hash.
+
+        Python's standard hash is not idempotent as it changes between
+        sessions. This hash can be used when an idempotent hash is
+        required.
+
+        Returns:
+            str: An hexstring encoding the hash.
+
+        Note:
+            This hash will be returned as an hexstring without
+            the '0x' prefix (unlike what is returned by 'hex()').
+        """
+        return self._safe_hash().hex()
+
     def __eq__(self, other: Any) -> bool:
         if not isinstance(other, RegisterLayout):
             return False

tests/test_register_layout.py

@@ -136,6 +136,12 @@ def test_repr(layout):
     assert repr(layout) == f"RegisterLayout_{hash_.hexdigest()}"
 
 
+def test_static_hash(layout):
+    int_hash = int.from_bytes(layout._safe_hash(), byteorder="big")
+    assert layout.static_hash() == f"{int_hash:x}"
+    assert repr(layout) == f"RegisterLayout_{layout.static_hash()}"
+
+
 def test_eq(layout, layout3d):
     assert RegisterLayout([[0, 0], [1, 0]]) != Register.from_coordinates(
         [[0, 0], [1, 0]]