I'd love to, but Haskell Platform ships with an old version of Cabal that doesn't have sandboxes. The new version of Cabal itself doesn't compile on the Mac. (In keeping with the theme of "nothing compiles.")
Edit: At least, I can't get the new version of Cabal/Cabal Install working on my Mac.
There was a relatively serious bug caused by Mavericks' clang being a non-standard CPP, but I think that's fixed in newer versions of GHC. It's certainly possible to get a Cabal compiled on Mac, though.
Against the usual recommendations, I install the Haskell platform with Homebrew. After that a 'cabal update ; cabal install cabal-install' gives a newer version without any problems.
Edit: At least, I can't get the new version of Cabal/Cabal Install working on my Mac.