[Python-Dev] Changing the Division Operator -- PEP 238, rev 1.12

[Samuele Pedroni]

Hi.

[Michael Hudson]
> Samuele Pedroni <pedroni@inf.ethz.ch> writes:
>
> > ...
> > > > >
> > > > > Does codeop currently work in Jython?  The solution should continue
to
> > > > > work in Jython then.
> > > > We have our interface compatible version of codeop that works.
> > >
> > > Would implementing the new interfaces I sketched out for codeop.py be
> > > possible in Jython?  That's the bit I care about, not so much the
> > > interface to __builtin__.compile.
> > Yes, it's of possible.
>
> Good; hopefully we can get somewhere then.
>
> > > > > Does Jython support the same flag bit values as
> > > > > CPython?  If not, Paul Prescod's suggestion to use keyword arguments
> > > > > becomes very relevant.
> > > > we support a subset of the co_flags, CO_NESTED e.g. is there with the
same
> > > > value.
> > > >
> > > > But the embedding API is very different, my implementation of nested
> > > > scopes does not define any Py_CF... flags, we have an internal
CompilerFlags
> > > > object but is more similar to PyFutureFeatures ...
> > >
> > > Is this object exposed to Python code at all?
> > Not publicily, but in Jython the separating line is a bit different,
> > because public java classes are always accessible from jython,
> > even most of the internals. That does not mean and every use of that
> > is welcome and supported.
>
> Ah, of course.  I'd forgotten how cool Jython was in some ways.
>
> > >  One approach would be
> > > PyObject-izing PyFutureFlags and making *that* the fourth argument to
> > > compile...
> > >
> > > class Compiler:
> > >     def __init__(self):
> > >         self.ff = ff.new() # or whatever
> > >     def __call__(self, source, filename, start_symbol):
> > >         code = compile(source, filename, start_symbol, self.ff)
> > >         self.ff.merge(code.co_flags)
> > >         return code
> > I see, "internally" we already have a compiler_flags function
> > that do the same of:
> > >         code = compile(source, filename, start_symbol, self.ff)
> > >         self.ff.merge(code.co_flags)
> >
> > where self.ff is a CompuilerFlags object.
> >
> > I can re-arrange things for any interface,
>
> Well, I don't want to make more work for you - I imagine Guido's doing
> enough of that for two!
>
> > I was only trying to explain our approach and situation and a
> > possible way to avoid duplicating some internal code in Python.
>
> Can you point me to the code in CVS that implements this sort of
> thing?  I don't really know Java but I can probably muddle through to
> some extent.  We might as well have CPython copy Jython for once...
I don't know if this can help you but the relevant stuff is in:
http://cvs.sourceforge.net/cgi-bin/viewcvs.cgi/jython/jython/org/python/modules
/codeop.java

http://cvs.sourceforge.net/cgi-bin/viewcvs.cgi/jython/jython/org/python/core/Co
mpilerFlags.java

http://cvs.sourceforge.net/cgi-bin/viewcvs.cgi/jython/jython/org/python/core/Py
.java
see compile_flags

http://cvs.sourceforge.net/cgi-bin/viewcvs.cgi/jython/jython/org/python/compile
r/Module.java
see compile and PyCode

http://cvs.sourceforge.net/cgi-bin/viewcvs.cgi/jython/jython/org/python/compile
r/CodeCompiler.java

http://cvs.sourceforge.net/cgi-bin/viewcvs.cgi/jython/jython/org/python/compile
r/Future.java

However implementing this approach in CPython is a bit more demanding because
we can import any java class from jython code, in CPython you cannot import a C
struct directly (for the obvious reasons)
you need an Extension Type :(.

regards, Samuele Pedroni.