[Haskell-cafe] Problem with prepose.lhs and ghc6.10.1

Henry Laxen nadine.and.henry at pobox.com
Thu Apr 2 11:59:30 EDT 2009

Dear Group,

I'm trying to read the paper:
"Functional Pearl: Implicit Configurations"
at http://www.cs.rutgers.edu/~ccshan/prepose/
and when running the code in prepose.lhs I get:
../haskell/prepose.lhs:707:0: Parse error in pattern
which is pointing at:
normalize a :: M s a = M (mod a (modulus (undefined :: s)))

The paper says it uses lexically scoped type variables.  I tried reading about
them at:

so I added -XScopedTypeVariables to my OPTIONS but I still get the same error
message.  I would really like to play with the code in the paper, but I'm stuck
at this point.  Any pointers would be appreciated.
Best wishes,
Henry Laxen

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