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-rw-r--r--lib/stdlib/src/dict.erl23
-rw-r--r--lib/stdlib/src/gb_trees.erl45
-rw-r--r--lib/stdlib/src/orddict.erl19
3 files changed, 84 insertions, 3 deletions
diff --git a/lib/stdlib/src/dict.erl b/lib/stdlib/src/dict.erl
index f921e28ef6..9449ba3dc2 100644
--- a/lib/stdlib/src/dict.erl
+++ b/lib/stdlib/src/dict.erl
@@ -38,7 +38,7 @@
%% 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]).
@@ -172,6 +172,27 @@ erase_key(Key, [E|Bkt0]) ->
{[E|Bkt1],Dc};
erase_key(_, []) -> {[],0}.
+-spec take(Key, Dict) -> {Value, Dict1} | error when
+ Dict :: dict(Key, Value),
+ Dict1 :: dict(Key, Value),
+ Key :: term(),
+ Value :: term().
+
+take(Key, D0) ->
+ Slot = get_slot(D0, Key),
+ case on_bucket(fun (B0) -> take_key(Key, B0) end, D0, Slot) of
+ {D1,{Value,Dc}} ->
+ {Value, maybe_contract(D1, Dc)};
+ {_,error} -> error
+ end.
+
+take_key(Key, [?kv(Key,Val)|Bkt]) ->
+ {Bkt,{Val,1}};
+take_key(Key, [E|Bkt0]) ->
+ {Bkt1,Res} = take_key(Key, Bkt0),
+ {[E|Bkt1],Res};
+take_key(_, []) -> {[],error}.
+
-spec store(Key, Value, Dict1) -> Dict2 when
Dict1 :: dict(Key, Value),
Dict2 :: dict(Key, Value).
diff --git a/lib/stdlib/src/gb_trees.erl b/lib/stdlib/src/gb_trees.erl
index 457287fa52..c0cdde012e 100644
--- a/lib/stdlib/src/gb_trees.erl
+++ b/lib/stdlib/src/gb_trees.erl
@@ -52,6 +52,13 @@
%% - delete_any(X, T): removes key X from tree T if the key is present
%% in the tree, otherwise does nothing; returns new tree.
%%
+%% - take(X, T): removes element with key X from tree T; returns new tree
+%% without removed element. Assumes that the key is present in the tree.
+%%
+%% - take_any(X, T): removes element with key X from tree T and returns
+%% a new tree if the key is present; otherwise does nothing and returns
+%% 'error'.
+%%
%% - balance(T): rebalances tree T. Note that this is rarely necessary,
%% but may be motivated when a large number of entries have been
%% deleted from the tree without further insertions. Rebalancing could
@@ -114,7 +121,8 @@
-export([empty/0, is_empty/1, size/1, lookup/2, get/2, insert/3,
update/3, enter/3, delete/2, delete_any/2, balance/1,
is_defined/2, keys/1, values/1, to_list/1, from_orddict/1,
- smallest/1, largest/1, take_smallest/1, take_largest/1,
+ smallest/1, largest/1, take/2, take_any/2,
+ take_smallest/1, take_largest/1,
iterator/1, iterator_from/2, next/1, map/2]).
@@ -416,6 +424,41 @@ merge(Smaller, Larger) ->
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+-spec take_any(Key, Tree1) -> {Value, Tree2} | 'error' when
+ Tree1 :: tree(Key, _),
+ Tree2 :: tree(Key, _),
+ Key :: term(),
+ Value :: term().
+
+take_any(Key, Tree) ->
+ case is_defined(Key, Tree) of
+ true -> take(Key, Tree);
+ false -> error
+ end.
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+-spec take(Key, Tree1) -> {Value, Tree2} when
+ Tree1 :: tree(Key, _),
+ Tree2 :: tree(Key, _),
+ Key :: term(),
+ Value :: term().
+
+take(Key, {S, T}) when is_integer(S), S >= 0 ->
+ {Value, Res} = take_1(Key, T),
+ {Value, {S - 1, Res}}.
+
+take_1(Key, {Key1, Value, Smaller, Larger}) when Key < Key1 ->
+ {Value2, Smaller1} = take_1(Key, Smaller),
+ {Value2, {Key1, Value, Smaller1, Larger}};
+take_1(Key, {Key1, Value, Smaller, Bigger}) when Key > Key1 ->
+ {Value2, Bigger1} = take_1(Key, Bigger),
+ {Value2, {Key1, Value, Smaller, Bigger1}};
+take_1(_, {_Key, Value, Smaller, Larger}) ->
+ {Value, merge(Smaller, Larger)}.
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
-spec take_smallest(Tree1) -> {Key, Value, Tree2} when
Tree1 :: tree(Key, Value),
Tree2 :: tree(Key, Value).
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).