%%
%% %CopyrightBegin%
%%
%% Copyright Ericsson AB 2013-2016. All Rights Reserved.
%%
%% Licensed under the Apache License, Version 2.0 (the "License");
%% you may not use this file except in compliance with the License.
%% You may obtain a copy of the License at
%%
%% http://www.apache.org/licenses/LICENSE-2.0
%%
%% Unless required by applicable law or agreed to in writing, software
%% distributed under the License is distributed on an "AS IS" BASIS,
%% WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
%% See the License for the specific language governing permissions and
%% limitations under the License.
%%
%% %CopyrightEnd%
%%
-module(maps).
-export([get/3,filter/2,fold/3, map/2,
size/1,
without/2, with/2]).
%%% BIFs
-export([get/2, find/2, from_list/1,
is_key/2, keys/1, merge/2,
new/0, put/3, remove/2,
to_list/1, update/3, values/1]).
-spec get(Key,Map) -> Value when
Key :: term(),
Map :: map(),
Value :: term().
get(_,_) -> erlang:nif_error(undef).
-spec find(Key,Map) -> {ok, Value} | error when
Key :: term(),
Map :: map(),
Value :: term().
find(_,_) -> erlang:nif_error(undef).
-spec from_list(List) -> Map when
List :: [{Key,Value}],
Key :: term(),
Value :: term(),
Map :: map().
from_list(_) -> erlang:nif_error(undef).
-spec is_key(Key,Map) -> boolean() when
Key :: term(),
Map :: map().
is_key(_,_) -> erlang:nif_error(undef).
-spec keys(Map) -> Keys when
Map :: map(),
Keys :: [Key],
Key :: term().
keys(_) -> erlang:nif_error(undef).
-spec merge(Map1,Map2) -> Map3 when
Map1 :: map(),
Map2 :: map(),
Map3 :: map().
merge(_,_) -> erlang:nif_error(undef).
-spec new() -> Map when
Map :: map().
new() -> erlang:nif_error(undef).
-spec put(Key,Value,Map1) -> Map2 when
Key :: term(),
Value :: term(),
Map1 :: map(),
Map2 :: map().
put(_,_,_) -> erlang:nif_error(undef).
-spec remove(Key,Map1) -> Map2 when
Key :: term(),
Map1 :: map(),
Map2 :: map().
remove(_,_) -> erlang:nif_error(undef).
-spec to_list(Map) -> [{Key,Value}] when
Map :: map(),
Key :: term(),
Value :: term().
to_list(_) -> erlang:nif_error(undef).
-spec update(Key,Value,Map1) -> Map2 when
Key :: term(),
Value :: term(),
Map1 :: map(),
Map2 :: map().
update(_,_,_) -> erlang:nif_error(undef).
-spec values(Map) -> Values when
Map :: map(),
Values :: [Value],
Value :: term().
values(_) -> erlang:nif_error(undef).
%%% End of BIFs
-spec get(Key, Map, Default) -> Value | Default when
Key :: term(),
Map :: map(),
Value :: term(),
Default :: term().
get(Key,Map,Default) when is_map(Map) ->
case maps:find(Key, Map) of
{ok, Value} ->
Value;
error ->
Default
end;
get(Key,Map,Default) ->
erlang:error({badmap,Map},[Key,Map,Default]).
-spec filter(Pred,Map1) -> Map2 when
Pred :: fun((Key, Value) -> boolean()),
Key :: term(),
Value :: term(),
Map1 :: map(),
Map2 :: map().
filter(Pred,Map) when is_function(Pred,2), is_map(Map) ->
maps:from_list([{K,V}||{K,V}<-maps:to_list(Map),Pred(K,V)]);
filter(Pred,Map) ->
erlang:error(error_type(Map),[Pred,Map]).
-spec fold(Fun,Init,Map) -> Acc when
Fun :: fun((K, V, AccIn) -> AccOut),
Init :: term(),
Acc :: term(),
AccIn :: term(),
AccOut :: term(),
Map :: map(),
K :: term(),
V :: term().
fold(Fun,Init,Map) when is_function(Fun,3), is_map(Map) ->
lists:foldl(fun({K,V},A) -> Fun(K,V,A) end,Init,maps:to_list(Map));
fold(Fun,Init,Map) ->
erlang:error(error_type(Map),[Fun,Init,Map]).
-spec map(Fun,Map1) -> Map2 when
Fun :: fun((K, V1) -> V2),
Map1 :: map(),
Map2 :: map(),
K :: term(),
V1 :: term(),
V2 :: term().
map(Fun,Map) when is_function(Fun, 2), is_map(Map) ->
maps:from_list([{K,Fun(K,V)}||{K,V}<-maps:to_list(Map)]);
map(Fun,Map) ->
erlang:error(error_type(Map),[Fun,Map]).
-spec size(Map) -> non_neg_integer() when
Map :: map().
size(Map) when is_map(Map) ->
erlang:map_size(Map);
size(Val) ->
erlang:error({badmap,Val},[Val]).
-spec without(Ks,Map1) -> Map2 when
Ks :: [K],
Map1 :: map(),
Map2 :: map(),
K :: term().
without(Ks,M) when is_list(Ks), is_map(M) ->
lists:foldl(fun(K, M1) -> ?MODULE:remove(K, M1) end, M, Ks);
without(Ks,M) ->
erlang:error(error_type(M),[Ks,M]).
-spec with(Ks, Map1) -> Map2 when
Ks :: [K],
Map1 :: map(),
Map2 :: map(),
K :: term().
with(Ks,Map1) when is_list(Ks), is_map(Map1) ->
Fun = fun(K, List) ->
case ?MODULE:find(K, Map1) of
{ok, V} ->
[{K, V} | List];
error ->
List
end
end,
?MODULE:from_list(lists:foldl(Fun, [], Ks));
with(Ks,M) ->
erlang:error(error_type(M),[Ks,M]).
error_type(M) when is_map(M) -> badarg;
error_type(V) -> {badmap, V}.
