Is it possible to implement find children/parent and spatial predicates with given geohash/H3 ?

I think the following functions can help some high level indexing for row / partition / file 

st_geohash_children ( geohash_str , next_n_level)
st_geohash_parent  ( geohash_str , previous_n_level)
st_geohash_contains ( geohash_str_large , geohash_str_small)
...


st_h3_children( h3_id, next_n_level)
st_h3_parent( h3_id, previous_n_level)
st_h3_contains( h3_id_large, h3_id_small)
...