split (== 'a') "aabbaca" == ["","","bb","c",""] split (== 'a') "" == [""] split (== ':') "::xyz:abc::123::" == ["","","xyz","abc","","123","",""] split (== ',') "my,list,here" == ["my","list","here"]
groupSortOn length ["test","of","sized","item"] == [["of"],["test","item"],["sized"]]
groupOn abs [1,-1,2] == [[1,-1], [2]]