Re: Wildcards in type synonyms

On Fri, 22 Jul 2022, Simon Peyton Jones wrote:

So it seems that instead of shoehorning it into the existing type synonyms, a better bet would be to branch off to a separate path quite early (maybe as soon as during renaming), expand them during typechecking, and *not* touch how/when existing "normal" type synonyms are resolved.

That sounds plausible, yes.

Do we have an existing way of substituting types over type variables, *in HsType instead of Core Type*?