Heh... Mint is an Ubuntu derivative, and Ubuntu is a Debian derivative. Not that important beyond the fact that Mint uses deb packages.
My guess is that your sources list does not include the right repository for the package. I'll do some searching to see if I can find out which repository it's in...
Well, it seems I couldn't find a straight answer. The packages website for Linux Mint is woeful in the list of packages for manual download. That tells me that anything not listed is probably direct from the Ubuntu repositories. On top of that, this page
says that there is currently a bug for unmet dependencies with haskell-platform. I do not know whether that bug affects your version of Mint though. But, according to that page, a user seems to have some success installing the haskell compiler from source.
You can download the source starting at this page
. DO NOT click the Mint link because it will take you back to the crap-tastic package website that didn't work for you earlier.
Scroll down and download the "haskell-platform-2011.4.0.0.tar.gz" AND
as the page indicates, you need to also install the glasgow haskell compiler (first link below the haskell-platform link).
There are instructions for compiling haskell-platform on that page. But in brief, you need to open a terminal, extract the tarball, configure, make, and make install. For instance, assuming (1) you installed the glasgow haskell compiler first
and (2) you downloaded the haskell-platform file to the Downloads directory in your home folder:
tar xvzf ~/Downloads/haskell-platform-2011.4.0.0.tar.gz
sudo make install