Compile minihaskell output to WASM about juvix

[paulcadman]

We tried using the asterius Haskell to WebAssembly compiler.

A validity predicate must be made available to the WASM runtime as a top-level function with a particular type-signature. So we need to be able to export Haskell functions via FFI using Asteruius.

We tried using foreign export javascript as described in tweag blog and in the Asterius test case. But this did not make the exported symbol available in the WASM output.

There's an open issue from 2020 for the same issue with exporting Haskell symbols that has not been looked at by maintainers of Asterius.

It seems like Asterius is not maintained. For example the project roadmap has not been updated since Q3 2021.

In summary we didn't find a way to get the FFI to work and so we can't use Asterius to compile validity predicates for use on the Anoma ledger.