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Diffstat (limited to 'lib/stdlib/src/orddict.erl')
| -rw-r--r-- | lib/stdlib/src/orddict.erl | 19 |
1 files changed, 18 insertions, 1 deletions
diff --git a/lib/stdlib/src/orddict.erl b/lib/stdlib/src/orddict.erl index 37cf0084f0..caa59099af 100644 --- a/lib/stdlib/src/orddict.erl +++ b/lib/stdlib/src/orddict.erl @@ -22,7 +22,7 @@ %% Standard interface. -export([new/0,is_key/2,to_list/1,from_list/1,size/1,is_empty/1]). --export([fetch/2,find/2,fetch_keys/1,erase/2]). +-export([fetch/2,find/2,fetch_keys/1,erase/2,take/2]). -export([store/3,append/3,append_list/3,update/3,update/4,update_counter/3]). -export([fold/3,map/2,filter/2,merge/3]). @@ -106,6 +106,23 @@ erase(Key, [{K,_}=E|Dict]) when Key > K -> erase(_Key, [{_K,_Val}|Dict]) -> Dict; %Key == K erase(_, []) -> []. +-spec take(Key, Orddict) -> {Value, Orddict1} | error when + Orddict :: orddict(Key, Value), + Orddict1 :: orddict(Key, Value), + Key :: term(), + Value :: term(). + +take(Key, Dict) -> + take_1(Key, Dict, []). + +take_1(Key, [{K,_}|_], _Acc) when Key < K -> + error; +take_1(Key, [{K,_}=P|D], Acc) when Key > K -> + take_1(Key, D, [P|Acc]); +take_1(_Key, [{_K,Value}|D], Acc) -> + {Value,lists:reverse(Acc, D)}; +take_1(_, [], _) -> error. + -spec store(Key, Value, Orddict1) -> Orddict2 when Orddict1 :: orddict(Key, Value), Orddict2 :: orddict(Key, Value). |