fix: add missing directory

marzipan/src/proverif/ast/attributemap.py

@@ -0,0 +1,33 @@
+from collections.abc import Mapping
+from typing import Any, Iterator
+
+
+class AttrMap(Mapping):
+    """
+    Small wrapper so that dict values can be accessed as {ctx.foo}
+    instead of only {ctx["foo"]} inside our custom format strings.
+    """
+
+    def __init__(self, mapping: Mapping[str, Any]):
+        self._mapping = mapping
+
+    def __getattr__(self, name: str) -> Any:
+        try:
+            return self._mapping[name]
+        except KeyError:
+            raise AttributeError(name) from None
+
+    def __getitem__(self, name: str) -> Any:
+        return self._mapping[name]
+
+    def __contains__(self, key: object) -> bool:
+        return key in self._mapping
+
+    def __str__(self) -> str:
+        return str(self._mapping)
+
+    def __iter__(self) -> Iterator[Any]:
+        return self._mapping.__iter__()
+
+    def __len__(self) -> int:
+        return len(self._mapping)