this patch touches only Python/ceval.c.
1. the only existing thing it modifies is PyEval_EvalFrameEx (adds 8
extra cases for the new 3.0 opcodes, doesn't mess w/ any of the existing
ones, or anything else as a matter of fact)
2. that, plus it defines (the new opcodes)
#define SET_ADD 17
#define STORE_MAP 54
#define STORE_LOCALS 69
#define LOAD_BUILD_CLASS 34
#define MAKE_BYTES 35
#define POP_EXCEPT 36
#define UNPACK_EX 94
#define BUILD_SET 109
and some backported vars & helper functions
only 2 contiguous areas of ceval.c is patched (1. & 2. - areas are
delimited by the comments '// py3k')
this simple patch seems sufficient in theory to allow the interpreter to
natively execute most of 3.0's language syntax (nonlocal, print,
extended unpacking... have been tested to work)
*the one exception being pep3102 - keyword-only arguments
i wrote 2 small scripts which gives an interactive function
'compile_py3k' similar to __builtin__.compile except it works only for
3.0 syntax. it doesn't actually compile, but rather cheats by querying
it to a python 3.0 server via pipe io.
here is an interactive demonstration of my script:
example demonstrating pep3132 extended unpacking syntax: a,b,*c = 1,2,3,4
Python 2.5.2 (r252:60911, Jun 27 2008, 21:19:51)
[GCC 3.4.6 20060404 (Red Hat 3.4.6-9)] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> import py3to2
py3to2 server restarting with io: (4, 5)
py3to2 server: Python 3.0b1 (r30b1:64395, Jun 24 2008, 21:53:55)
py3to2 server: [GCC 3.4.6 20060404 (Red Hat 3.4.6-9)] on linux2
py3to2 server: Type "help", "copyright", "credits" or "license" for more
information.
py3to2 server:
>>> src = "a,b,*c = 1,2,3,4"
>>> codeobject = py3to2.compile_py3k(src,"","exec")
1 0 LOAD_CONST 5 ((1, 2, 3, 4))
3 UNPACK_EX_py3k 2
6 STORE_NAME 0 (a)
9 STORE_NAME 1 (b)
12 STORE_NAME 2 (c)
15 LOAD_CONST 4 (None)
18 RETURN_VALUE
>>> exec(codeobject); print "a=%s, b=%s, c=%s"%(a,b,c)
a=1, b=2, c=[3, 4]
>>>
u can go c
http://pypi.python.org/pypi?name=py3to2&version=20080628&:action=display
for more info
anyway, i think it would b a great boost for python 3.0 (which i think
is very cool) if developers can test/develop it under the robust 2.5
environment. this patch plus some scripts could go a long way in making
that happen
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