Or_error (rose_tree.Rose_tree.Deferred.Or

val iter : 
  'a t ->
  f:( 'a -> unit Async_kernel.Deferred.Or_error.t ) ->
  unit Async_kernel.Deferred.Or_error.t

val map : 
  'a t ->
  f:( 'a -> 'b Async_kernel.Deferred.Or_error.t ) ->
  'b t Async_kernel.Deferred.Or_error.t

val fold_map : 
  'a t ->
  init:'b ->
  f:( 'b -> 'a -> 'b Async_kernel.Deferred.Or_error.t ) ->
  'b t Async_kernel.Deferred.Or_error.t

val fold_map_over_subtrees : 
  'a t ->
  init:'b ->
  f:( 'b -> 'a t -> 'b Async_kernel.Deferred.Or_error.t ) ->
  'b t Async_kernel.Deferred.Or_error.t