Haoyu Bai, 03.04.2010 14:15: > On Sat, Apr 3, 2010 at 6:50 PM, Stefan Behnel<[email protected]> wrote: >> Haoyu Bai, 03.04.2010 09:18: >>> Thinking about how to implement Cython decorators (@cclass, @cfunc >>> etc.) for pure Python mode, I come up with an idea of "compile-time >>> decorator". Basically, we want these decorators to have effect during >>> compile time, rather than normal Python decorator that is called in >>> runtime. So, to implement @cfunc, we can actually implement a function >>> cfunc(node), which inputs a DefNode and transform it to a >>> CFuncDefNode, then put the function into the compile-time scope. >> >> -1, we shouldn't expose Cython compiler internals to the language level. >> >> It's better to use a transform that intercepts on certain decorators. > > By implement @cfunc as a function, I'm not mean to implement it *in > Cython*, it is still a part of the Cython compiler, as the transforms. > And the main motivation is not to expose Cython internal to the users, > but to have a flexible mechanism to support the various decorators - > Cython directives, @cclass @cfunc, and even some Python builtin > decorator (@classmethod, @staticmethod and @property). > > These are decorators need to be executed in compile time. Currently, > the code to deal with these decorators are scattered in many places, > some in transforms, some in nodes. It would be better to have a > unified mechanism to deal with all of these decorators. That's what I > proposed. > > Indeed, the node classes do not provide an API so we should not expose > them to end-user. But there is nothing to prevent us to write > compile-time function to process them inside Cython (and decorator is > just functions).
In that case, there is nothing to gain from making them "compile time evaluated functions", because the implementation itself would still be inside of the compiler. So the decorator would still just be a name for something that is triggered inside of the compiler, which may be a code block, a function, a method or a whole transformation class. While I do not doubt that there is potential for a code cleanup, the main reason why the "decorators are scattered in many places" is that their implementation requires code to be executed during different compiler stages. This cannot be helped by stuffing everything into a single function. Stefan _______________________________________________ Cython-dev mailing list [email protected] http://codespeak.net/mailman/listinfo/cython-dev
