Patches item #1223381, was opened at 2005-06-18 23:08 Message generated for change (Comment added) made by pje You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=305470&aid=1223381&group_id=5470
Please note that this message will contain a full copy of the comment thread, including the initial issue submission, for this request, not just the latest update. Category: Core (C code) Group: Python 2.5 Status: Open Resolution: None Priority: 5 Submitted By: Phillip J. Eby (pje) Assigned to: Phillip J. Eby (pje) Summary: PEP 342 Generator enhancements Initial Comment: The attached patch implements code and test changes for: * yield expressions * bare yield (short for yield None) * yield in try/finally * generator.send(value) (send value into generator; substituted for PEP 342's next(arg)) * generator.throw(typ[,val[,tb]]) (raise error in generator) * generator.close() (per PEP 343) * GeneratorExit built-in exception type * generator.__del__ (well, the C equivalent) * All necessary mods to the compiler, parser module, and Python 'compiler' package to support these changes. It was necessary to change a small part of the eval loop (well, the initialization, not the loop) and the gc module's has_finalizer() logic in order to support a C equivalent to __del__. Specialists in these areas should probably scrutinize this patch! There is one additional implementation detail that was not contemplated in either PEP. in order to prevent used-up generators from retaining unnecessary references to their frame's contents, I set the generator's gi_frame member to None whenever the generator finishes normally or with an error. Thus, an exhausted generator cannot be part of a cycle, and it releases its frame object sooner than in previous Python versions. For generators used only in a direct "for" loop, this makes no difference, but for generators used with the iterator protocol (i.e. "gen.next()") from Python, this avoids stranding the generator's frame in a traceback cycle. ---------------------------------------------------------------------- >Comment By: Phillip J. Eby (pje) Date: 2005-07-31 21:10 Message: Logged In: YES user_id=56214 mwh, is the only difference in your patch the addition of the incref? ---------------------------------------------------------------------- Comment By: Michael Hudson (mwh) Date: 2005-07-07 14:14 Message: Logged In: YES user_id=6656 You missed an incref in gen_throw (symptom was Fatal Python error: ../Objects/tupleobject.c:169 object at 0x4013807c has negative ref count -606348326 on exit after running test_generators). New patch attached. ---------------------------------------------------------------------- Comment By: Guido van Rossum (gvanrossum) Date: 2005-06-28 07:10 Message: Logged In: YES user_id=6380 Since I've accepted PEP 342+343 last night in my Europython keynote, you can check this in now. ---------------------------------------------------------------------- Comment By: Phillip J. Eby (pje) Date: 2005-06-27 15:40 Message: Logged In: YES user_id=56214 I had hoped to be able to avoid dealing with string exceptions, but I guess it makes sense that if somebody has thrown one, it should be able to propagate. So I guess I'll take care of that along with the rest. ---------------------------------------------------------------------- Comment By: Michael Hudson (mwh) Date: 2005-06-27 15:31 Message: Logged In: YES user_id=6656 Heh heh heh. ---------------------------------------------------------------------- Comment By: Guido van Rossum (gvanrossum) Date: 2005-06-27 15:22 Message: Logged In: YES user_id=6380 (Removing 343 from the subject since all this is now in PEP 342.) Playing with the code a bit, I notice that throw() doesn't like string exceptions. That could cause some problems. Also, I think the tb argument should be allowed to be None. Otherwise, great! In a few hours you can check it in. :-) ---------------------------------------------------------------------- Comment By: Michael Hudson (mwh) Date: 2005-06-23 23:20 Message: Logged In: YES user_id=6656 Fair enough. I want to use with statements in a presentation at EuroPython next week, so I've hacked together a truly horrible implementation that will do for now and will see about a real one some time after... ---------------------------------------------------------------------- Comment By: Phillip J. Eby (pje) Date: 2005-06-23 23:07 Message: Logged In: YES user_id=56214 No, I haven't, and I never really planned to be the person implementing "with". Doesn't mean I might not end up doing it eventually, but it's not currently in my plans. I'm going to have my hands full just updating PEP 342 (Guido has asked me to take it over), and getting docs written to go with this patch. Between all that and my distutils-related work, my pro-bono Python project time is booked up solid for maybe the next 2 months or so. ---------------------------------------------------------------------- Comment By: Michael Hudson (mwh) Date: 2005-06-22 20:59 Message: Logged In: YES user_id=6656 Argh, I'd hoped you'd done with, too :) Have you done any work on that yet? ---------------------------------------------------------------------- Comment By: Reinhold Birkenfeld (birkenfeld) Date: 2005-06-19 07:37 Message: Logged In: YES user_id=1188172 Minor nit: on line 642, 'yield_stmt' should be changed to 'yield_expr'. ---------------------------------------------------------------------- You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=305470&aid=1223381&group_id=5470 _______________________________________________ Patches mailing list [email protected] http://mail.python.org/mailman/listinfo/patches
