darcs patch: rewrite of Distribution.Simple.Haddock

[Duncan Coutts]

On Thu, 2009-02-19 at 16:44 +0100, Andrea Vezzosi wrote:
> Thu Feb 19 16:37:38 CET 2009  Andrea Vezzosi <sanzhiyan at gmail.com>
>   * rewrite of Distribution.Simple.Haddock
>   In addition to (hopefully) making clear what's going on
>   we now do the additional preprocessing for all the versions of haddock 
>   (but not for hscolour) and we run cpp before moving the files.

Looks a lot nicer. I'll apply it and see how things go. One thing we
need to address:

-D__HADDOCK__

It's important that we only use this with haddock-1.x. Lots of packages
use this conditional to hide things from haddock 1. However for haddock
2.x the package actually has to be syntactically correct which
haddock-1.x did not require. So using -D__HADDOCK__ with 2.x can make it
not work. We should check if haddock-2.x defines any cpp macros when it
does it's own cpp'ing and follow that.

Duncan