I am not against this proposal,  but want to raise a possible future concern.

As part of improving the haskell tooling environment I am keen on making GHC incremental, and have started a proof of concept based in the same techniques as used in the tree-sitter library.

This is achieved by modifying happy, and requires minimal changes to the existing Parser.y.

It would be unfortunate if this possibility was prevented by this rewrite.

Alan