Template Haskell stability

[Viktor Dukhovni]

On Mon, Mar 11, 2024 at 08:43:26AM +0000, Simon Peyton Jones wrote:

> >     *  in 2.4 we could have kept the type signature of `dataD` as (it
> > would make a plain type binder), and added a new function `dataDTyVarBnd`
> > for the new behavior
> 
> 
> Iavor, what about *pattern matching *on DataD?   Or don't you do that?
> 
> If we exclude pattern matching on TH syntax, it becomes much more feasible
> to make a stable API.  Is that a goal worth seeking?  Would it help a few
> people?  A lot of people?

Can't speak for anyone else, but I would find stable API combinators
quite helpful.  Pattern matching the constructors falls outside my
modest needs.

Can't say Whether that materially changes barriers to adopting new GHC
releases across the ecosystem, since this would have to also simplify
migration for various widely used libraries, and I hope their
maintainers will contribute to the thread.

-- 
    Viktor.