You need to build a copy of GHC with this diff. I've already patched it onto GHC-8.6.5 if you'd prefer that, and also built it for linux boxes.
To be honest, I'm not really sure how to install this thing; I just stuck it
into ~/.stack/programs/x86_64-linux/ and pretended it was a real ghc-variant.
Name it ghc-custom-dyna4-tinfo6.
You also need a hacked version of brick downloaded side-by-side.
- Expose the editing actions as an effect
- Describe editing targets via srcspans
- Effect for getting info on srcspans -- what's in scope, what type it is, etc (don't actually need a hacked GHC for this)
Interfaces and abstraction boundaries! Maybe the OOP guys got it right!