2015-05-06 22:18 GMT+02:00 Johannes Waldmann
There is maybe another option: do what csharp does.
Define a reduced "preprocessor" (for conditional compilation, but without macro expansion) as part of the language. (cf. https://msdn.microsoft.com/en-us/library/ed8yd1ha.aspx )
I'd like to repeat that this is *not* a full solution IMHO, everybody doing cross-platform FFI bindings needs macro expansion to handle the differences in calling conventions. Of course this can be done by duplicating all "foreign imports" etc. for every calling convention involved, but this is not really a solution to actual needs.
They must have have had good reasons for doing it this way.
"Doing things differently" has always been a tradition for certain companies... ;-) More seriously: We don't want to break hundreds of packages on Hackage, the only thing we really need is a well-defined CPP-like preprocessor, so integrating e.g. cpphs somehow seems to be the right way IMHO. If it's not cpphs, I wouldn't mind, the main point is that it's the same on all platforms and handles basically *all* things CPP can. TH is nice, but I'm not sure if it can handle 100% of the CPP use cases, and remember: There are Haskell implementations out there which don't support TH.