Tue May 21 08:03:20 EDT 2019

State + Reader

So kick out the let-insertion monad.  It's a neat trick, and it works
if state forks are not an issue.  For my use case however a more plain
environment + state approach seems appropriate.

To collect bindings, should I use a writer?  Or should the bindings go
in the state.

EDIT: This works a lot better.  loop can now explicty run the inner
forms, threading environment and state.