On Thu, 15 Apr 2004 11:13:34 +0100, Simon Marlow
Robert Will writes:
I think what Haskellers (and others) can do in most cases is to factor out platform dependent parts to mini-modules which have different implementations but the same interface. The version of such a module is choosen by the path it resides in during the build process. (Simplest case: the -i option of the compiler.)
I agree with you that in general we should avoid a preprocessor. However, in the DData case it is hard to see a different solution. Using a "mini module" to do the bit-fiddling won't work that well since 1) It is imperative for performance that the ghc "shiftRL#" gets inlined, which doesn't happen if it is in a separate module. 2) As part of the standard libraries, you can't have three extra modules for each system I don't say that I *like* to use cpp here, but it is surely the easiest solution here -- not perfect, but the perfect solution would take an inappropiate amount of resources. All the best, Daan.