1 files changed, 13 insertions, 0 deletions
diff --git a/robots/utils.py b/robots/utils.py
index e269a02..5793a00 100644
--- a/robots/utils.py
+++ b/robots/utils.py
@@ -10,6 +10,19 @@ def ceil_div(a, b):
 def ilen(items):
     return sum(1 for _ in items)
 
+def immutable(value):
+    if isinstance(value, str):
+        return value
+    try:
+        return immutable(list(sorted(value.items())))
+    except AttributeError:
+        pass
+    try:
+        return tuple(immutable(v) for v in value)
+    except TypeError:
+        pass
+    return value
+
 def add_spawns(map_, n_spawns, city=None):
     available = []
     for x, y, cell in iter_board(map_):