* Relaxed the argument restrictions for non-operator methods. They now
allow any iterable instead of requiring a set. This makes the module
a little easier to use and paves the way for an efficient C
implementation which can take better advantage of iterable arguments
while screening out immutables.
* Deprecated Set.update() because it now duplicates Set.union_update()
* Adapted the tests and docs to include the above changes.
* Added more test coverage including testing identities and checking
to make sure non-restartable generators work as arguments.
Will backport to Py2.3.1 so that the interface remains consistent
across versions. The deprecation of update() will be changed to
a FutureWarning.
Allow mixed-type __eq__ and __ne__ for Set objects. This is messier than
I'd like because Set *also* implements __cmp__. I know of one glitch now:
cmp(s, t) returns 0 now when s and t are both Sets and s == t, despite
that Set.__cmp__ unconditionally raises TypeError (and by intent). The
rub is that __eq__ gets tried first, and the x.__eq__(y) True result
convinces Python that cmp(x, y) is 0 without even calling Set.__cmp__.
* Removed the ifilter flag wart by splitting it into two simpler functions.
* Fixed comment tabbing in C code.
* Factored module start-up code into a loop.
Documentation:
* Re-wrote introduction.
* Addede examples for quantifiers.
* Simplified python equivalent for islice().
* Documented split of ifilter().
Sets.py:
* Replace old ifilter() usage with new.
is not supported on sets. (Unfortunately, sorting a list of sets may
still return random results because it uses < exclusively, but for
sets that inly implements a partial ordering. Oh well.)
instead of into a list for a bit of speed/space savings. Reopened the
bug report too (628246), as I'm unclear on why we don't sort out the
cause of the TypeError instead.
The _update method detected mutable elements by trapping TypeErrors.
Unfortunately, this masked useful TypeErrors raised by the iterable
itself. For cases where it is possible for an iterable to raise
a TypeError, the iterable is pre-converted to a list outside the
try/except so that any TypeErrors propagate through.