On Fri, Sep 26, 2008 at 4:43 PM, Dag Sverre Seljebotn <[EMAIL PROTECTED]> wrote: > If you have a couple of evenings I'm happy to help with pointers as it would > be a good investment of time. > > I can write more later when I'm not on my phone, but: I'd suggest starting > with implementing > > @cython.earlybind > def f(x, y): ... > > and have it turn to > > cpdef f(x, y): ... > > (note on the name below) > > Just getting this working, with arguments and result typed to "object", > should get your feet wet. Then I suppose the next step is implementing the > Py3 PEP supporting decorators on arguments and return type. (I think one > should aim for Py2.6+ here, though I suppose arguments to the decorator could > work too: @cython.earlybind(x=cython.uint, localvar=cython.float)...opinions?
I need it to be working with python2.4+, so I'll choose something that works in python2.4. Debian just switched to python2.5 recently, so it's a long, long way before python2.6 could become a de facto standard. But generally I agree one should design this so that things are especially easy in python2.6+. > > Brief scetch on the first step anyway (please ask about any hazy points and > I'll give better help when I'm at a computer): > > 1) The file you want to work in is ParseTreeTransforms.py. Your goal is to > intercept decorated DefNode-s and transform them into CFuncDefNodes. Have a > look and see how transforms are written... > > 2) The ResolveDirectives transform (or something like that) already has code > in it to intercept @cython.X-decorators on functions for compiler directives, > I think you want to extend that transform, in time changing the name > appropriately to give it a wider scope. > > 3) the general workflow is this: Create a small testcase with both "from" > code and "to" code as given above. Then add this function to > ResolveDirectives (not entirely sure about the node class name, see Nodes.py): > > def visit_CFuncDefNode(self, node): > print node.dump() > return node > > this gives you an idea about the node structure you must convert to. > > 5) To transform, edit the function visit_DefNode to also take into account > "earlybind" (hardcode it) before checking the decorator against directives, > and if so, simply set node = self.convert_def_to_cpdef(node), which you > write. "node.dump()" here gives you the from-tree. > > 6) if you fancy unit tests in addition to integration tests, have a look at > TestWithTransform.py (or similar) for how to do it. You should literally be > able to input the decorated def example above as a string and assert that the > result after the transform is the expected cpdef version... though you may > need to extend CodeWriter.py to serialize cpdef to strings. > > Send an email whenever something is not obvious -- it would be really cool to > see this in Cython. > > Note on names: It is easily changeable so it is not a big point...but here > goes: I think personally the cdef and cpdef are very cython-specific and > communicate badly with python users. Also, considering cpdef exists, I think > the need for cdef should be small? If wanted it could be called > "@cython.nativeonly" perhaps. Anyway, "earlybind" also gets in the important > message that you cannot reassign the symbol it binds to at runtime, which is > a difference with how you expect a "def" to work. Thanks a lot for the help! I'll give it a shot and report back. Ondrej _______________________________________________ Cython-dev mailing list [email protected] http://codespeak.net/mailman/listinfo/cython-dev
