atomo-0.4: prelude/continuation.atomo

(v: Block) before: (b: Block) := v before: b after: { @ok }
(v: Block) after: (a: Block) := v before: { @ok } after: a
(init: Block) wrap: cleanup do: action :=
  { action call: x } before: { x = init call } in-context after: { cleanup call: x }