Make.ExnInteracting between monads and language exceptions
val expect : 
  ?finally:(unit -> unit T1(M).t) ->
  f:(unit -> 'a T1(M).t) ->
  catch:(exn -> 'a T1(M).t) ->
  'a T1(M).texpect ?finally ~f ~catch evaluates f (), if an exception e is raised during the evaluation (or call) then the result of whole computation will be catch e. If an optional argument ?finally is passed the finally is called after f () computation or after catch e if an exception was raised.