and I have a few basic questions that I'm hoping someone might be able to shed some light on.

1. I seem to be having some issues with importing Parsec modules for instance.

"import Parsec" as outlined in the introduction causes errors as does a number of the imports used later on in the paper and a solution that I have found is to further specify "import Text.Parsec" is this due to some changes to importing since the paper was written (in 2001 I believe)? 

2. Can anyone recommend if this is a good source to learn to use the Parsec Library or if there are any other recommended documents I would benefit from ? 

3. I have also tried to run the files that I have created in hugs and ghc and while they work in ghc, hugs on the other hand complains about the import statements I making e.g. "import Text.Parsec.Expr"

Thanks in advance for any help!!

Seán