2012/5/9 Stefan Behnel <stefan...@behnel.de>: > Vitja Makarov, 09.05.2012 09:43: >> 2012/5/9 Stefan Behnel <stefan...@behnel.de>: >>> Vitja Makarov, 08.05.2012 13:27: >>>> I've noticed regression related to callable() optimization. >>>> >>>> https://github.com/cython/cython/commit/a40112b0461eae5ab22fbdd07ae798d4a72ff523 >>>> >>>> class C: >>>> pass >>>> print callable(C()) >>>> >>>> It prints True optimized version checks ((obj)->ob_type->tp_call != >>>> NULL) condition that is True for both class and instance. >>>> >>>>>>> help(callable) >>>> callable(...) >>>> callable(object) -> bool >>>> >>>> Return whether the object is callable (i.e., some kind of function). >>>> Note that classes are callable, as are instances with a __call__() >>>> method. >>> >>> Ah, right - old style classes are special cased in Py2. >>> >>> I'll make this a Py3-only optimisation then. >>> >> >> I don't see difference between py2 and py3 here: >> >> Python 3.2.3 (default, May 3 2012, 15:51:42) >> [GCC 4.6.3] on linux2 >> Type "help", "copyright", "credits" or "license" for more information. >> >>> class Foo: pass >> ... >> >>> callable(Foo()) >> False >> >>> >> >> There is PyCallable_Check() CPython function: >> >> int >> PyCallable_Check(PyObject *x) >> { >> if (x == NULL) >> return 0; >> if (PyInstance_Check(x)) { >> PyObject *call = PyObject_GetAttrString(x, "__call__"); >> if (call == NULL) { >> PyErr_Clear(); >> return 0; >> } >> /* Could test recursively but don't, for fear of endless >> recursion if some joker sets self.__call__ = self */ >> Py_DECREF(call); >> return 1; >> } >> else { >> return x->ob_type->tp_call != NULL; >> } >> } > > That's the Py2 version. In Py3, it looks as follows, because old-style > "instances" no longer exist: > > """ > int > PyCallable_Check(PyObject *x) > { > if (x == NULL) > return 0; > return x->ob_type->tp_call != NULL; > } > """ > > That's what I had initially based my optimisation on. >
Ok, so why don't you want to use PyCallable_Check() in all cases? -- vitja. _______________________________________________ cython-devel mailing list cython-devel@python.org http://mail.python.org/mailman/listinfo/cython-devel
