It was easier than I thought, assuming that no other things contribute
to the instance size besides slots -- a pretty good bet. With a test
suite, no less!
happy if one could delete the __dict__ attribute of an instance. I
love to make Jim happy, so here goes...
- New-style objects now support deleting their __dict__. This is for
all intents and purposes equivalent to assigning a brand new empty
dictionary, but saves space if the object is not used further.
int_mul(): new and vastly simpler overflow checking. Whether it's
faster or slower will likely vary across platforms, favoring boxes
with fast floating point. OTOH, we no longer have to worry about
people shipping broken LONG_BIT definitions <0.9 wink>.
There's now a new structmember code, T_OBJECT_EX, which is used for
all __slot__ variables (except __weakref__, which has special behavior
anyway). This new code raises AttributeError when the variable is
NULL rather than converting NULL to None.
string object (or a Unicode that's trivially converted to ASCII).
PyObject_GetAttr(): add an 'else' to the Unicode test like
PyObject_SetAttr() already has.
Rather than tweaking the inheritance of type object slots (which turns
out to be too messy to try), this fix adds a __hash__ to the list and
dict types (the only mutable types I'm aware of) that explicitly
raises an error. This has the advantage that list.__hash__([]) also
raises an error (previously, this would invoke object.__hash__([]),
returning the argument's address); ditto for dict.__hash__.
The disadvantage for this fix is that 3rd party mutable types aren't
automatically fixed. This should be added to the rules for creating
subclassable extension types: if you don't want your object to be
hashable, add a tp_hash function that raises an exception.
Also, it's possible that I've forgotten about other mutable types for
which this should be done.
SF patch #480716 by Greg Chapman fixes the problem that super's
__get__ method always returns an instance of super, even when the
instance whose __get__ method is called is an instance of a subclass
of super.
Other issues fixed:
- super(C, C()).__class__ would return the __class__ attribute of C()
rather than the __class__ attribute of the super object. This is
confusing. To fix this, I decided to change the semantics of super
so that it only applies to code attributes, not to data attributes.
After all, overriding data attributes is not supported anyway.
- While super(C, x) carefully checked that x is an instance of C,
super(C).__get__(x) made no such check, allowing for a loophole.
This is now fixed.
slot_tp_descr_set(): When deleting an attribute described by a
descriptor implemented in Python, the descriptor's __del__ method is
called by the slot_tp_descr_set dispatch function. This is bogus --
__del__ already has a different meaning. Renaming this use of __del__
is renamed to __delete__.
Bugfix candidate.
int_repr(): we've never had a buffer big enough to hold the largest
possible result on a 64-bit box. Now that we're using snprintf instead
of sprintf, this can lead to nonsense results instead of random stack
corruption.
pass the buffer length. Stop using it. It should be deprecated, but too
late in the release cycle to do that now.
New static format_float() does the same thing but requires passing the
buffer length too. Use it instead.
const char* instead of char*. The change is conceptually correct, and
indirectly fixes a compiler wng introduced when somebody else innocently
passed a const char* to this function.
sprintf() to PyOS_snprintf() for buffer overrun avoidance.
complex_print(), complex_repr(), complex_str(): Call complex_to_buf()
passing in sizeof(buf).
confusing error messages. If a new-style class has no sequence or
mapping behavior, attempting to use the indexing notation with a
non-integer key would complain that the sequence index must be an
integer, rather than complaining that the operation is not supported.
of multiple inheritance from a mix of new- and classic-style classes.
This is his patch, plus a start at some test cases from me. Will check
in more, plus a NEWS blurb, later tonight.
object, so the "Metroworks only" section should not decref it in case
of error (the caller is responsible for decref'ing in case of error --
and does).
helping for types that defined tp_richcmp but not tp_compare, although
that's when it's most valuable, and strings moved into that category
since the fast path was first introduced. Now it helps for same-type
non-Instance objects that define rich or 3-way compares.
For all the edits here, the rest just amounts to moving the fast path from
do_richcmp into PyObject_RichCompare, saving a layer of function call
(measurable on my box!). This loses when NESTING_LIMIT is exceeded, but I
don't care about that (fast-paths are for normal cases, not pathologies).
Also added a tasteful <wink> label to get out of PyObject_RichCompare, as
the if/else nesting in this routine was getting incomprehensible.
Try to ensure that divmod(-0.0, 1.0) -> (-0.0, +0.0) across platforms.
It always did on Windows, and still does. It didn't on Linux. Alas,
there's no platform-independent way to write a test case for this.
Bugfix candidate.
presence of NaNs. So pass the issue on to the platform libm fabs();
after all, fabs() is a std C function because you can't implement it
correctly in portable C89.
should just avoid calling it in the first place to avoid waiting for a repr
of a large object like a dict or list. The result of PyObject_Repr() was
being leaked as well.
Bugfix candidate!
XXX Remaining problems:
- The GC module doesn't know about these; I think it has its reasons
to disallow calling __del__, but for now, __del__ on new-style
objects is called when the GC module discards an object, for better
or for worse.
- The code to call a __del__ handler is really ridiculously
complicated, due to all the different debug #ifdefs. I've copied
this from the similar code in classobject.c, so I'm pretty sure I
did it right, but it's not pretty. :-(
- No tests yet.
object.h: Added PyType_CheckExact macro.
typeobject.c, type_new():
+ Use the new macro.
+ Assert that the arguments have the right types rather than do incomplete
runtime checks "sometimes".
+ If this isn't the 1-argument flavor() of type, and there aren't 3 args
total, produce a "types() takes 1 or 3 args" msg before
PyArg_ParseTupleAndKeywords produces a "takes exactly 3" msg.
Guido van Rossum
Tim Peters
Martin v. Löwis
Jack Jansen
Barry Warsaw
Marc-André Lemburg
Jeremy Hylton
Fred Drake
Michael W. Hudson