diff options
| -rw-r--r-- | lib/stdlib/src/maps.erl | 11 |
1 files changed, 11 insertions, 0 deletions
diff --git a/lib/stdlib/src/maps.erl b/lib/stdlib/src/maps.erl index 4ef1638e6d..b8b284db65 100644 --- a/lib/stdlib/src/maps.erl +++ b/lib/stdlib/src/maps.erl @@ -24,6 +24,7 @@ map/2, size/1, without/2, + only/2, get/3 ]). @@ -201,3 +202,13 @@ size(Map) when is_map(Map) -> without(Ks, M) when is_list(Ks), is_map(M) -> maps:from_list([{K,V}||{K,V} <- maps:to_list(M), not lists:member(K, Ks)]). + + +-spec only(Ks, Map1) -> Map2 when + Ks :: [K], + Map1 :: map(), + Map2 :: map(), + K :: term(). + +only(Ks, M) when is_list(Ks), is_map(M) -> + maps:from_list([{K,V}||{K,V} <- maps:to_list(M), lists:member(K, Ks)]). |