On Tue, Jul 28, 2015 at 11:18 AM, Ian Henriksen <insertinterestingnameh...@gmail.com> wrote: > > On Tue, Jul 28, 2015 at 1:36 AM Robert Bradshaw <rober...@gmail.com> wrote: >> >> Sorry for not getting back sooner... responses below. >> >> On Mon, Jul 20, 2015 at 2:06 PM, Ian Henriksen >> <insertinterestingnameh...@gmail.com> wrote: >> > Hi all, >> > I've spent a little time working on adding support for non-type >> > template parameters. In doing this, it has been very easy to add >> > support for doing something like the following: >> > >> > cdef extern from "add_const.hpp" nogil: >> > int myfunc1[i](int) >> > def test(): >> > print myfunc1[2](a) >> > >> > The downside of this is that it does not let the Cython compiler >> > distinguish between different kinds of template parameters. >> > >> > Stricter checking could be added using a syntax like this: >> > >> > cdef extern from "add_const.hpp" nogil: >> > int myfunc1[int i](int) >> > def test(): >> > print myfunc1[2](a) >> > >> > The downsides here are that the syntax doesn't really match the >> > existing template syntax. It will also complicate the Cython codebase >> > since we'll have to go to greater lengths to allow or disallow all the >> > different special cases for templates. >> > >> > Which version would be preferable? >> >> I think I'd prefer the [int i] syntax. Hopefully it shouldn't >> complicate things too much. > > Okay, I think I see a way to make that work. On the other hand, since there > weren't any replies here, I've already nearly finished implementing the > first > syntax. I'll spend another hour or two finishing it off later today and > submit a PR > so you can look it over. I originally favored the first syntax because it > minimizes > the number of fancy template features (SFINAE, for example) we have to worry > about on the Cython end. I'm still open to discuss it though.
I think this falls into the "explicit is better than implicit" bucket. That and getting obscure template errors that could have been caught at Cython compile time will be very nice. >> > On a similar note, for variadic templates, would we prefer something >> > like >> > >> > cdef extern from "my_variadic.hpp" nogil: >> > T myfunc2[T,...](T, ...) >> > >> > or something like: >> > >> > cdef extern from "my_variadic.hpp" nogil: >> > T myfunc2[T, Types...](T, Types... args) >> > >> > Again, the latter syntax is more explicit, but it will require much more >> > complicated code in Cython. It also doesn't match the existing syntax >> > very well. The former syntax matches the existing syntax for templates >> > better, but will make it hard for Cython to raise errors early on in >> > compilation. >> >> Hmm... this is a tougher call. Let's go with the former for now. > > > I like the former a lot more. It will keep the syntax simpler on our end and > I > haven't been able to find any case that it doesn't cover. This will also be > significantly easier to implement. I'll take a look at it soon. Sounds good. There's also the question of default arguments. Let's adopt the [type T = *] syntax for that. >> > I'd greatly appreciate any input on the best syntax for either use-case. >> > >> > Regards, >> > >> > -Ian Henriksen >> > >> > _______________________________________________ >> > cython-devel mailing list >> > cython-devel@python.org >> > https://mail.python.org/mailman/listinfo/cython-devel >> > >> _______________________________________________ >> cython-devel mailing list >> cython-devel@python.org >> https://mail.python.org/mailman/listinfo/cython-devel > > > _______________________________________________ > cython-devel mailing list > cython-devel@python.org > https://mail.python.org/mailman/listinfo/cython-devel > _______________________________________________ cython-devel mailing list cython-devel@python.org https://mail.python.org/mailman/listinfo/cython-devel
