%%
%% %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,
update_with/3, update_with/4,
without/2, with/2,
iterator/1, next/1]).
%% BIFs
-export([get/2, find/2, from_list/1,
is_key/2, keys/1, merge/2,
new/0, put/3, remove/2, take/2,
to_list/1, update/3, values/1]).
-opaque iterator() :: {term(), term(), iterator()}
| none | nonempty_improper_list(integer(),map()).
-export_type([iterator/0]).
-dialyzer({no_improper_lists, iterator/1}).
-define(IS_ITERATOR(I), is_tuple(I) andalso tuple_size(I) == 3; I == none; is_integer(hd(I)) andalso is_map(tl(I))).
%% Shadowed by erl_bif_types: maps:get/2
-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).
%% Shadowed by erl_bif_types: maps:from_list/1
-spec from_list(List) -> Map when
List :: [{Key,Value}],
Key :: term(),
Value :: term(),
Map :: map().
from_list(_) -> erlang:nif_error(undef).
%% Shadowed by erl_bif_types: maps:is_key/2
-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).
%% Shadowed by erl_bif_types: maps:merge/2
-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).
%% Shadowed by erl_bif_types: maps:put/3
-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 take(Key,Map1) -> {Value,Map2} | error when
Key :: term(),
Map1 :: map(),
Value :: term(),
Map2 :: map().
take(_,_) -> erlang:nif_error(undef).
-spec to_list(Map) -> [{Key,Value}] when
Map :: map(),
Key :: term(),
Value :: term().
to_list(Map) when is_map(Map) ->
to_list_internal(erts_internal:map_next(0, Map, []));
to_list(Map) ->
erlang:error({badmap,Map},[Map]).
to_list_internal([Iter, Map | Acc]) when is_integer(Iter) ->
to_list_internal(erts_internal:map_next(Iter, Map, Acc));
to_list_internal(Acc) ->
Acc.
%% Shadowed by erl_bif_types: maps:update/3
-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 update_with(Key,Fun,Map1) -> Map2 when
Key :: term(),
Map1 :: map(),
Map2 :: map(),
Fun :: fun((Value1 :: term()) -> Value2 :: term()).
update_with(Key,Fun,Map) when is_function(Fun,1), is_map(Map) ->
try maps:get(Key,Map) of
Val -> maps:update(Key,Fun(Val),Map)
catch
error:{badkey,_} ->
erlang:error({badkey,Key},[Key,Fun,Map])
end;
update_with(Key,Fun,Map) ->
erlang:error(error_type(Map),[Key,Fun,Map]).
-spec update_with(Key,Fun,Init,Map1) -> Map2 when
Key :: term(),
Map1 :: Map1,
Map2 :: Map2,
Fun :: fun((Value1 :: term()) -> Value2 :: term()),
Init :: term().
update_with(Key,Fun,Init,Map) when is_function(Fun,1), is_map(Map) ->
case maps:find(Key,Map) of
{ok,Val} -> maps:update(Key,Fun(Val),Map);
error -> maps:put(Key,Init,Map)
end;
update_with(Key,Fun,Init,Map) ->
erlang:error(error_type(Map),[Key,Fun,Init,Map]).
-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,MapOrIter) -> Map when
Pred :: fun((Key, Value) -> boolean()),
Key :: term(),
Value :: term(),
MapOrIter :: map() | iterator(),
Map :: map().
filter(Pred,Map) when is_function(Pred,2), is_map(Map) ->
maps:from_list(filter_1(Pred, iterator(Map)));
filter(Pred,Iterator) when is_function(Pred,2), ?IS_ITERATOR(Iterator) ->
maps:from_list(filter_1(Pred, Iterator));
filter(Pred,Map) ->
erlang:error(error_type(Map),[Pred,Map]).
filter_1(Pred, Iter) ->
case next(Iter) of
{K, V, NextIter} ->
case Pred(K,V) of
true ->
[{K,V} | filter_1(Pred, NextIter)];
false ->
filter_1(Pred, NextIter)
end;
none ->
[]
end.
-spec fold(Fun,Init,MapOrIter) -> Acc when
Fun :: fun((K, V, AccIn) -> AccOut),
Init :: term(),
Acc :: term(),
AccIn :: term(),
AccOut :: term(),
MapOrIter :: map() | iterator(),
K :: term(),
V :: term().
fold(Fun,Init,Map) when is_function(Fun,3), is_map(Map) ->
fold_1(Fun,Init,iterator(Map));
fold(Fun,Init,Iterator) when is_function(Fun,3), ?IS_ITERATOR(Iterator) ->
fold_1(Fun,Init,Iterator);
fold(Fun,Init,Map) ->
erlang:error(error_type(Map),[Fun,Init,Map]).
fold_1(Fun, Acc, Iter) ->
case next(Iter) of
{K, V, NextIter} ->
fold_1(Fun, Fun(K,V,Acc), NextIter);
none ->
Acc
end.
-spec map(Fun,MapOrIter) -> Map when
Fun :: fun((K, V1) -> V2),
MapOrIter :: map() | iterator(),
Map :: map(),
K :: term(),
V1 :: term(),
V2 :: term().
map(Fun,Map) when is_function(Fun, 2), is_map(Map) ->
maps:from_list(map_1(Fun, iterator(Map)));
map(Fun,Iterator) when is_function(Fun, 2), ?IS_ITERATOR(Iterator) ->
maps:from_list(map_1(Fun, Iterator));
map(Fun,Map) ->
erlang:error(error_type(Map),[Fun,Map]).
map_1(Fun, Iter) ->
case next(Iter) of
{K, V, NextIter} ->
[{K, Fun(K, V)} | map_1(Fun, NextIter)];
none ->
[]
end.
-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 iterator(Map) -> Iterator when
Map :: map(),
Iterator :: iterator().
iterator(M) when is_map(M) -> [0 | M];
iterator(M) -> erlang:error({badmap, M}, [M]).
-spec next(Iterator) -> {Key, Value, NextIterator} | 'none' when
Iterator :: iterator(),
Key :: term(),
Value :: term(),
NextIterator :: iterator().
next({K, V, I}) ->
{K, V, I};
next([Path | Map]) when is_integer(Path), is_map(Map) ->
erts_internal:map_next(Path, Map, iterator);
next(none) ->
none;
next(Iter) ->
erlang:error(badarg, [Iter]).
-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) -> maps: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 maps:find(K, Map1) of
{ok, V} ->
[{K, V} | List];
error ->
List
end
end,
maps:from_list(lists:foldl(Fun, [], Ks));
with(Ks,M) ->
erlang:error(error_type(M),[Ks,M]).
error_type(M) when is_map(M); ?IS_ITERATOR(M) -> badarg;
error_type(V) -> {badmap, V}.
