1%%
2%% %CopyrightBegin%
3%%
4%% Copyright Ericsson AB 2008-2017. All Rights Reserved.
5%%
6%% Licensed under the Apache License, Version 2.0 (the "License");
7%% you may not use this file except in compliance with the License.
8%% You may obtain a copy of the License at
9%%
10%%     http://www.apache.org/licenses/LICENSE-2.0
11%%
12%% Unless required by applicable law or agreed to in writing, software
13%% distributed under the License is distributed on an "AS IS" BASIS,
14%% WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
15%% See the License for the specific language governing permissions and
16%% limitations under the License.
17%%
18%% %CopyrightEnd%
19%%
20
21-module(dict_test_lib).
22
23-export([new/2]).
24
25new(Mod, Eq) ->
26    fun (enter, {K,V,D}) -> enter(Mod, K, V, D);
27	(empty, []) -> empty(Mod);
28	(equal, {D1,D2}) -> Eq(D1, D2);
29	(from_list, L) -> from_list(Mod, L);
30	(module, []) -> Mod;
31	(size, D) -> Mod:size(D);
32	(is_empty, D) -> Mod:is_empty(D);
33        (iterator, S) -> Mod:iterator(S);
34        (iterator_from, {Start, S}) -> Mod:iterator_from(Start, S);
35        (next, I) -> Mod:next(I);
36	(to_list, D) -> to_list(Mod, D);
37	(erase, {K,D}) -> erase(Mod, K, D);
38	(take, {K,D}) -> take(Mod, K, D)
39    end.
40
41empty(Mod) ->
42    %% The dict module might not be loaded since it not used by
43    %% anything in the core parts of Erlang/OTP.
44    {module,Mod} = code:ensure_loaded(Mod),
45    case erlang:function_exported(Mod, new, 0) of
46	false -> Mod:empty();
47	true -> Mod:new()
48    end.
49
50to_list(Mod, D) ->
51    Mod:to_list(D).
52
53from_list(Mod, L) ->
54    {module,Mod} = code:ensure_loaded(Mod),
55    case erlang:function_exported(Mod, from_orddict, 1) of
56	false ->
57	    Mod:from_list(L);
58	true ->
59	    %% The gb_trees module has no from_list/1 function.
60	    %%
61	    %% The keys in S are not unique. To make sure
62	    %% that we pick the same key/value pairs as
63	    %% dict/orddict, first convert the list to an orddict.
64	    Orddict = orddict:from_list(L),
65	    Mod:from_orddict(Orddict)
66    end.
67
68%% Store new value into dictionary or update previous value in dictionary.
69enter(Mod, Key, Val, Dict) ->
70    {module,Mod} = code:ensure_loaded(Mod),
71    case erlang:function_exported(Mod, store, 3) of
72	false ->
73	    Mod:enter(Key, Val, Dict);
74	true ->
75	    Mod:store(Key, Val, Dict)
76    end.
77
78erase(Mod, Key, Val) when Mod =:= dict; Mod =:= orddict ->
79    Mod:erase(Key, Val);
80erase(gb_trees, Key, Val) ->
81    gb_trees:delete_any(Key, Val).
82
83take(gb_trees, Key, Val) ->
84    Res = try
85	      gb_trees:take(Key, Val)
86	  catch
87	      error:_ ->
88		  error
89	  end,
90    Res = gb_trees:take_any(Key, Val);
91take(Mod, Key, Val) ->
92    Mod:take(Key, Val).
93