Ross Paterson
Hugs's implementation of -F is a bit clunky: - it slows everything down (Hugs examines most modules twice: first to get the imports and later to actually read the whole thing, so a preprocessor gets run twice) - error handling is terrible
Yeah, probably a bad idea to force cpp on all users, whether they want it or not.
I agree with Henrik about doing the preprocessing for Hugs at installation or packaging time, so that users don't need the full environment. That's what currently happens with the fptools libraries.
OK, so I think we are probably agreed on this then: * When Cabal is installing for Hugs, it does 'cpp -D__HUGS__' (or equivalent) on all Haskell source files, as it copies them into the installation location. If any more complicated situations arise between the ordering of cpp and other preprocessors, use a chain of file extensions to disambiguate? e.g. .ly.cpp = cpp first -> .ly, then literate happy to get .hs file. .cpp.ly = literate happy -> .cpp.hs, then cpp to get plain .hs file. Regards, Malcolm