[Haskell-cafe] Alternative dependencies in Cabal file

[Matthias Reisner]

Hi,

for a package I need to ensure the user uses a certain package 
configuration. So how would I rewrite the following pseudo-cabal 
description?

    Build-Depends: packageA < X,           packageB < Y
                     or
                   packageA >= X && < X',  packageB >= Y && < Y'
                     or
                   packageA >= X',         packageB >= Y'

    Build-Depends: ... common dependencies ...

where neither A nor B is the base package. Maybe I have to use if/else 
blocks, but I don't know what conditions to use then.


Regards,

Matthias