On 19 October 2004 13:42, Malcolm Wallace wrote:

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Another solution is to adopt a new extension for plain Haskell, say .phs. The conversion from .hs to .phs is either via CPP or just 'cat', depending on some setting somewhere.

Not very pretty.

True :-)

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Also, I recommend that we use the compiler itself for preprocessing:

ghc -E foo.hs -o foo.phs

You are right that the compiler is best placed to define pp symbols, so this is all very well, but neither nhc98 nor Hugs currently have the -E option to stop immediately after pp. And come to think of it, the only real reason to have cpp done separately at all is because Hugs does not have a preprocessor call builtin, like ghc and nhc98 do. So maybe the best solution is to ship Hugs with -F"cpphs.hugs" enabled by default? Then no separate extension would be required, and Cabal could just defer all cpp-ing to the compiler.

That would be fine, except that Cabal might want to get access to the raw CPP'd source file for two reasons I can think of: - calculating dependencies, like hmake does - running Haddock As long as you can do preprocessing with 'ghc -E' or similar (cpphs?) then everything's fine. Cheers, Simon