transpose_array() applied to an alist results in an array of ({ key, data }) pairs, useful if you want to use sort_array() or filter_array() on the alist.
sort_array(transpose_array( ({ m_indices(map), m_values(map) }) ),
lambda( ({ 'a, 'b }),
({ #'<, ({ #'[, 'a, 0 }),
({ #'[, 'b, 0}) }) )
The given mapping 'map' is returned as an array of
({ key, data }) pairs, sorted by the keys.