multiple cabal files in one directory?

Hi, Is it possible to have a directory with multiple cabal files, telling cabal which file to use for a given install request by passing in a flag, say something like:

cabal install -f pads.cabal or cabal install -f forest.cabal

In other words, something like the -f option in make. I looked through the cabal documentation, but didn't see an option for specifying the cabal file to use. Did I just fail to see the proper flag? or does it not exist? If it doesn't, is that just because it hasn't been implemented, or is there a Good Reason? Thanks for any pointers and explanations! Kathleen