State.hs does not work?

[dnmfarrell]

$ runhaskell State.hs
State.hs:30:19: Not in scope: type constructor or class ‘RS.State’

[elisehuard]

hi, this is because State.hs is not meant to run on its own, but has dependencies. I advise you to use cabal, as described in the README - it will load all the required dependencies (in this case gloss-rendering). If you want to use runhaskell directly it will require quite a lot more arguments to load all the dependencies.
Let me know if this helps?