[Haskell-beginners] Code review: Go challenge #1 in Haskell

[Ramakrishnan Muthukrishnan]

Hello Haskellers:

A few weeks ago, there was this thing called "Go challenge" and a
problem was posted¹ on decoding a binary format and printing out the
drum sequences in the input binary file.

I made a Haskell solution and would love to get some code reviews.

 <https://github.com/vu3rdd/drum>

One of the input files given does not have the full bitstream and my
program cannot parse that yet. I had been thinking about using a Monad
transformer to make a `Get (Maybe) a' and output whatever it could parse
and leave the rest behind, instead of failing completely.

¹ http://golang-challenge.com/go-challenge1/

(fwiw, the challenge is over.)

Thanks in advance,
Ramakrishnan