This introduces:
- A new operator // that means floor division (the kind of division
where 1/2 is 0).
- The "future division" statement ("from __future__ import division)
which changes the meaning of the / operator to implement "true
division" (where 1/2 is 0.5).
- New overloadable operators __truediv__ and __floordiv__.
- New slots in the PyNumberMethods struct for true and floor division,
new abstract APIs for them, new opcodes, and so on.
I emphasize that without the future division statement, the semantics
of / will remain unchanged until Python 3.0.
Not yet implemented are warnings (default off) when / is used with int
or long arguments.
This has been on display since 7/31 as SF patch #443474.
Flames to /dev/null.
particular, str(long) and repr(long) use base 10, and that gets a factor
of 4 speedup). Another factor of 2 can be gotten by refactoring divrem1 to
support in-place division, but that started getting messy so I'm leaving
that out.
raising an error. This was one of the two issues that the VPython
folks were particularly problematic for their students. (The other
one was integer division...) This implements (my) SF patch #440487.
is allocated than needed (used to allocate 80 bytes of digit space no
matter how small the long input). This also runs faster, at least on 32-
bit boxes.
Replaced PyLong_{As,From}{Unsigned,}LongLong guts with calls
to _PyLong_{As,From}ByteArray.
_testcapimodule.c:
Added strong tests of PyLong_{As,From}{Unsigned,}LongLong.
Fixes SF bug #432552 PyLong_AsLongLong() problems.
Possible bugfix candidate, but the fix relies on code added to longobject
to support the new q/Q structmodule format codes.
This completes the q/Q project.
longobject.c _PyLong_AsByteArray: The original code had a gross bug:
the most-significant Python digit doesn't necessarily have SHIFT
significant bits, and you really need to count how many copies of the sign
bit it has else spurious overflow errors result.
test_struct.py: This now does exhaustive std q/Q testing at, and on both
sides of, all relevant power-of-2 boundaries, both positive and negative.
NEWS: Added brief dict news while I was at it.
_PyLong_FromByteArray
_PyLong_AsByteArray
Untested and probably buggy -- they compile OK, but nothing calls them
yet. Will soon be called by the struct module, to implement x-platform
'q' and 'Q'.
If other people have uses for them, we could move them into the public API.
See longobject.h for usage details.
raise ValueError. Checked in the patch as far as it went, but also changed
all of ints, longs and floats to raise ZeroDivisionError instead when raising
0 to a negative number. This is what 754-inspired stds require, as the "true
result" is an infinity obtained from finite operands, i.e. it's a singularity.
Also changed float pow to not be so timid about using its square-and-multiply
algorithm. Note that what math.pow does is unrelated to what builtin pow
does, and will still vary by platform.
