úΧportablejmillikin@gmail.com IA list-like type for lazy sequences which might terminate with an error. 8Standard lists can be converted to failable lists using  Prelude.foldr Next Done. Like the standard ( function, but the mapping function may  return an error. Like the standard " function, but accepting an extra  parameter to handle  items. Like the standard Data.List.unfoldr! function, but the step function  may return an error.      failable-list-0.1Data.FailableList FailableListFailDoneNextmapfoldrunfoldrbaseGHC.Basehead'tail'