Changed comments to make sense now that the LazyList-based

examples no longer require any explicit closing to avoid
leaking.

That the tee-based examples still do is (I think) still a
mystery.  Part of the mystery is that gc.garbage remains
empty:  if it were the case that some generator in a trash
cycle said it needed finalization, suppressing collection
of that cycle, that generator _would_ show up in gc.garbage.

So this is acting more like, e.g., some tp_traverse slot
isn't visiting all the pointers it should (in which case
the skipped pointer(s) would act like an external root,
silently suppressing collection of everything reachable
from it(them)).

diff --git a/Lib/test/test_generators.py b/Lib/test/test_generators.py
index b44d63788f14d68f5c0889f17dbdff541af184a2..4b2ed8fff41a0f2d000553b881a8443374053b2b 100644 (file)
--- a/Lib/test/test_generators.py
+++ b/Lib/test/test_generators.py
@@ -700,11 +700,12 @@ result for as long as it has not been "consumed" from all of the duplicated
 iterators, whereupon it is deleted. You can therefore print the hamming
 sequence during hours without increasing memory usage, or very little.
 
-The beauty of it is that recursive running after their tail FP algorithms
+The beauty of it is that recursive running-after-their-tail FP algorithms
 are quite straightforwardly expressed with this Python idiom. The problem is
-that this creates the same kind of reference cycle as the m235()
-implementation above, and again we have to explicitly close the innermost
-generator to clean up the cycle.
+that this creates an uncollectable reference cycle, and we have to explicitly
+close the innermost generator to clean up the cycle.
+XXX As of 14-Apr-2006, Tim doubts that anyone understands _why_ some cycle
+XXX is uncollectable here.
 
 Ye olde Fibonacci generator, tee style.
 
@@ -730,6 +731,7 @@ Ye olde Fibonacci generator, tee style.
 [1, 2, 3, 5, 8, 13, 21, 34, 55, 89, 144, 233, 377, 610, 987, 1597, 2584]
 >>> closer()
 
+XXX Again the tee-based approach leaks without an explicit close().
 """
 
 leak_test1 = """