MonadProgram typeclass for nicer transformer stacks about operational HOT 2 CLOSED

ping @HeinrichApfelmus?

from operational.

Hm, I don't know. An instance of the MonadProgram class only works with a single instruction type. However, I have always perceived Program as a general way to implement monads, so it should be possible to stack different monads that were individually built with ProgramT.

Also, I'm not entirely happy about the interplay between Program and monad transformers anyway. The thing is that monads can be combined in two ways: As monad transformers or by taking the disjoint union of their corresponding instruction types. Because of this redundancy, I am somewhat reluctant to add more support for monad transformers to the library.

from operational.