[Haskell-cafe] configurable mapping between data declarations and given XML schema?

[Johannes Waldmann]

Dear Cafe,

I have a legacy XML schema, and some Haskell data declarations.
I want to map bidirectionally between XML documents and data.

I absolutely cannot change the schema. I could change the data
declarations, but it would not help much, since I don't think
there is any form  of declaring data that would allow me
to derive the transformations generically.

So, I have a mess of ad-hoc transformations.
What could be done about this?
I think I need "generic with customization".

More detail: https://github.com/jwaldmann/haskell-tpdb/issues/16

Comments appreciated.

- J.W.