Effects

General approaches

1. How equivalent are uniqueness typing and monads? In particular, what do the two look like when handing world state changes such as freezing/thawing regions of memory?
2. We can handle imperative region effects by treating IO as “all” regions and adding various splitting operators that take pieces out of IO. We’ll also need types for “IO minus a region” for this purpose. This all seems doable with the standard duck type system, since >>= can take two different monad types and produce a third.

It seems that we’ve likely settled for now on effect typing.

Effect types

• How much do effects need to be annotated in type signatures? How much can be inferred?