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.
This is really stupid because it cannot be suppressed or altered using
the warning framework; that's because the warning framework is built
on Python interpreter internals, and the parser generator doesn't have
access to any of those (you cannot use anything of type PyObject * in
the parser).
But it's better than nothing, and implementing a proper check for this
appears to require modifying compile.c in a dozen places, for which I
don't have the stamina today. I promise we'll do better in 2.2a2.
At least it tells you the filename and line number (unlike the first
hack I considered :-).
that 'yield' is a keyword. This doesn't help test_generators at all! I
don't know why not. These things do work now (and didn't before this
patch):
1. "from __future__ import generators" now works in a native shell.
2. Similarly "python -i xxx.py" now has generators enabled in the
shell if xxx.py had them enabled.
3. This program (which was my doctest proxy) works fine:
from __future__ import generators
source = """\
def f():
yield 1
"""
exec compile(source, "", "single") in globals()
print type(f())
the yield statement. I figure we have to have this in before I can
release 2.2a1 on Wednesday.
Note: test_generators is currently broken, I'm counting on Tim to fix
this.
#115555.
The error from s_push() on stack overflow was -1, which was passed
through unchanged by push(), but not tested for by push()'s caller --
which only expected positive error codes. Fixed by changing s_push()
to return E_NOMEM on stack overflow. (Not quite the proper error code
either, but I can't be bothered adding a new E_STACKOVERFLOW error
code in all the right places.)
Add definitions of INT_MAX and LONG_MAX to pyport.h.
Remove includes of limits.h and conditional definitions of INT_MAX
and LONG_MAX elsewhere.
This closes SourceForge patch #101659 and bug #115323.
Add the EXTENDED_ARG opcode to the virtual machine, allowing 32-bit
arguments to opcodes instead of being forced to stick to the 16-bit
limit. This is especially useful for machine-generated code, which
can be too long for the SET_LINENO parameter to fit into 16 bits.
This closes the implementation portion of SourceForge patch #100893.
fields token and expected must also be initialized, otherwise the
tests in parsetok() can generate uninitialized memory read errors.
This quiets an Insure warning.
