Re: [Haskell-cafe] Replacing CPP [was: Current status of Mavericks CPP]

Erik Hesselink wrote:

On Wed, Apr 16, 2014 at 2:48 PM, Ben Franksen wrote:

...

There are people on this list who grep the whole of hackage in a matter of minutes whenever someone (seriously) proposes some non-compatible change to see who many libraries would be affected. (Any volunteers?) My guess is that no more than a few hands full of the hackage packages use more than conditional compilation, but I may be completely wrong about that.

I think some core packages like base and (IIRC) containers use CPP to define instances and such.

Ok, these would still have to use CPP, until we have something more suitable.

One conditional compilation feature that's used relatively often and not covered by your earlier proposal is bounds checks on libraries through cabal. It could be handled the same way as GHC versions, of course, but I think the triple of version numbers is a bit more 'correct' and flexible.

Can you point me to an example or some documentation? I am not too familiar with advanced cabal usage... Cheers Ben -- "Make it so they have to reboot after every typo." -- Scott Adams