Hell's Parser

[chrisdone]

HSE is a good parser, but not maintained so it's on borrowed time, and doesn't have some modern things like foo.bar record access.

Options:

• Patch HSE. Downside is the bitrot and leaning into a dead library.
• Adopt ghc-lib-parser (fairly laborious rewrite of the desugarer, but not complex). Downside is the sheer size and maintenance burden that inevitably comes from depending on GHC's API (burned enough times..).
• Snatch the parser from Lennart's MicroHS and then shrink it down to what I need. Downside: Bugs? Unexpected programs that parse differently from GHC?
• Write my own parser. Downside: I'm not that motivated to do this once again. And bugs.

HSE not supporting foo.bar kind of forces this thunk, so I'll have to pick something.