Connect legacy Haskell code and Fay code

Question

I have some Haskell code, and would like a Fay script to be able to access it. The problem is the Haskell code uses monads. Fay doesn't support arbitrary monads. How do I get my Haskell code to work with Fay? Namely, the Fay script needs to be able to access functions from the Haskell script. What do I do?

Answer 1

I may not quite understand what you are asking.

You have some Haskell that isn't valid Fay, so if you want to run it as Fay code you would need to replace unsupported features, for example by using monomorphic functions to replace the missing Monad instances (note that you can use RebindableSyntax here)

If you compile the Haskell code with GHC there is no reasonable way to interface with the functions from Fay. You would need to invoke an external process from Fay inside node.js or similar.