improvements to defer

thirdparty/defer/defer.py

@@ -2,7 +2,6 @@ import sys
 from typing import Any, Callable, ParamSpec, TypeVar
 
 from defer._defer import _Defer
-from defer.sugar._parse import _ParseDefer
 
 P = ParamSpec("P")
 T = TypeVar("T")
@@ -11,7 +10,7 @@ T = TypeVar("T")
 class Defer:
     def __call__(self, fn: Callable[P, T], *args: P.args, **kwargs: P.kwargs):
         if sys.gettrace() is None:
-            sys.settrace(_ParseDefer.IDENTITY)
+            sys.settrace(_DeferTrace())
         frame = sys._getframe(1)
         if not isinstance(frame.f_trace, _Defer):
             frame.f_trace = _Defer(frame.f_trace)
@@ -21,3 +20,9 @@ class Defer:
     def __contains__(self, fn: Any):
         breakpoint()
         self(fn)
+
+
+class _DeferTrace:
+    """Minimal no-op trace for when @defer is used but no other trace is active."""
+    def __call__(self, frame, event, arg):
+        return self