From 342270d6e5b92a7197505da177473c89dcdcd1b8 Mon Sep 17 00:00:00 2001
From: igorls <4753812+igorls@users.noreply.github.com>
Date: Mon, 27 Apr 2026 03:15:09 -0300
Subject: [PATCH] fix(palace_graph): defer annotation eval for Python 3.9
 compat
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``def _normalize_wing(wing: str | None) -> str | None`` uses PEP 604
union syntax which requires Python 3.10+ at runtime. The project still
declares ``python_requires=">=3.9"`` and CI runs the test-linux (3.9)
matrix, where every test in ``tests/test_palace_graph*`` errors out
before collection with ``TypeError: unsupported operand type(s) for |``.

Added ``from __future__ import annotations`` so all annotations in
this module are evaluated lazily as strings — the union syntax is then
accepted on 3.9 without needing to rewrite to ``Optional[str]``.

Surfaced after rebasing this PR onto current develop.
---
 mempalace/palace_graph.py | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/mempalace/palace_graph.py b/mempalace/palace_graph.py
index 5e6ccbf..3296cd5 100644
--- a/mempalace/palace_graph.py
+++ b/mempalace/palace_graph.py
@@ -15,6 +15,11 @@ Enables queries like:
 No external graph DB needed — built from ChromaDB metadata.
 """
 
+# PEP 604 (``str | None``) needs 3.10+ at runtime; the project still
+# supports 3.9, so defer annotation evaluation to keep the union syntax
+# working on the older interpreter.
+from __future__ import annotations
+
 import hashlib
 import json
 import logging