Add take/2 to all dictionary modules

Similar to maps:take/2, add take/2 to the other dictionary
modules in STDLIB:

  orddict:take(Key, Dict) -> {Val,NewDict} | 'error'.
  dict:take(Key, Dict) -> {Val,NewDict} | 'error'.
  gb_trees:take(Key, Dict) -> {Val,NewDict}.

For gb_trees also add:

  gb_trees:take_any(Key, Dict) -> {Val,NewDict} | 'error'.

gb_trees already has delete() and delete_any(), so we will
follow that design pattern.

Suggested by Boris Bochkaryov in https://github.com/erlang/otp/pull/1209.

2 files changed, 43 insertions, 4 deletions

diff --git a/lib/stdlib/test/dict_SUITE.erl b/lib/stdlib/test/dict_SUITE.erl
index 47358d729f..e99af9ad42 100644
--- a/lib/stdlib/test/dict_SUITE.erl
+++ b/lib/stdlib/test/dict_SUITE.erl
@@ -23,10 +23,10 @@
 
 -module(dict_SUITE).
 
--export([all/0, suite/0,groups/0,init_per_suite/1, end_per_suite/1, 
+-export([all/0, suite/0,groups/0,init_per_suite/1, end_per_suite/1,
 	 init_per_group/2,end_per_group/2,
 	 init_per_testcase/2,end_per_testcase/2,
-         create/1,store/1,iterate/1]).
+	 create/1,store/1,iterate/1,remove/1]).
 
 -include_lib("common_test/include/ct.hrl").
 
@@ -37,7 +37,7 @@ suite() ->
      {timetrap,{minutes,5}}].
 
 all() -> 
-    [create, store, iterate].
+    [create, store, remove, iterate].
 
 groups() -> 
     [].
@@ -92,6 +92,27 @@ store_1(List, M) ->
     end,
     D0.
 
+remove(_Config) ->
+    test_all([{0,87}], fun remove_1/2).
+
+remove_1(List0, M) ->
+    %% Make sure that keys are unique. Randomize key order.
+    List1 = orddict:from_list(List0),
+    List2 = lists:sort([{rand:uniform(),E} || E <- List1]),
+    List = [E || {_,E} <- List2],
+    D0 = M(from_list, List),
+    remove_2(List, D0, M).
+
+remove_2([{Key,Val}|T], D0, M) ->
+    {Val,D1} = M(take, {Key,D0}),
+    error = M(take, {Key,D1}),
+    D2 = M(erase, {Key,D0}),
+    true = M(equal, {D1,D2}),
+    remove_2(T, D1, M);
+remove_2([], D, M) ->
+    true = M(is_empty, D),
+    D.
+
 %%%
 %%% Test specifics for gb_trees.
 %%%
diff --git a/lib/stdlib/test/dict_test_lib.erl b/lib/stdlib/test/dict_test_lib.erl
index 7c4c3572ae..f6fef7bdf4 100644
--- a/lib/stdlib/test/dict_test_lib.erl
+++ b/lib/stdlib/test/dict_test_lib.erl
@@ -33,7 +33,9 @@ new(Mod, Eq) ->
         (iterator, S) -> Mod:iterator(S);
         (iterator_from, {Start, S}) -> Mod:iterator_from(Start, S);
         (next, I) -> Mod:next(I);
-	(to_list, D) -> to_list(Mod, D)
+	(to_list, D) -> to_list(Mod, D);
+	(erase, {K,D}) -> erase(Mod, K, D);
+	(take, {K,D}) -> take(Mod, K, D)
     end.
 
 empty(Mod) ->
@@ -67,3 +69,19 @@ enter(Mod, Key, Val, Dict) ->
 	true ->
 	    Mod:store(Key, Val, Dict)
     end.
+
+erase(Mod, Key, Val) when Mod =:= dict; Mod =:= orddict ->
+    Mod:erase(Key, Val);
+erase(gb_trees, Key, Val) ->
+    gb_trees:delete_any(Key, Val).
+
+take(gb_trees, Key, Val) ->
+    Res = try
+	      gb_trees:take(Key, Val)
+	  catch
+	      error:_ ->
+		  error
+	  end,
+    Res = gb_trees:take_any(Key, Val);
+take(Mod, Key, Val) ->
+    Mod:take(Key, Val).