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-rw-r--r--lib/stdlib/src/maps.erl83
1 files changed, 47 insertions, 36 deletions
diff --git a/lib/stdlib/src/maps.erl b/lib/stdlib/src/maps.erl
index ba4d6a5c87..533ff08726 100644
--- a/lib/stdlib/src/maps.erl
+++ b/lib/stdlib/src/maps.erl
@@ -19,31 +19,16 @@
-module(maps).
--export([
- fold/3,
- map/2,
- size/1,
- without/2,
- with/2,
- get/3
- ]).
+-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
- ]).
+-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(),
@@ -150,13 +135,28 @@ values(_) -> erlang:nif_error(undef).
Value :: term(),
Default :: term().
-get(Key, Map, Default) ->
+get(Key,Map,Default) when is_map(Map) ->
case maps:find(Key, Map) of
{ok, Value} ->
Value;
error ->
Default
- end.
+ 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
@@ -169,8 +169,10 @@ get(Key, Map, Default) ->
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) 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),
@@ -180,18 +182,19 @@ fold(Fun, Init, Map) when is_function(Fun,3), is_map(Map) ->
V1 :: term(),
V2 :: term().
-map(Fun, Map) when is_function(Fun, 2), is_map(Map) ->
- maps:from_list(lists:map(fun
- ({K,V}) ->
- {K,Fun(K,V)}
- end,maps:to_list(Map))).
+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).
+ erlang:map_size(Map);
+size(Val) ->
+ erlang:error({badmap,Val},[Val]).
-spec without(Ks,Map1) -> Map2 when
@@ -200,8 +203,10 @@ size(Map) when is_map(Map) ->
Map2 :: map(),
K :: term().
-without(Ks, M) when is_list(Ks), is_map(M) ->
- maps:from_list([{K,V}||{K,V} <- maps:to_list(M), not lists:member(K, Ks)]).
+without(Ks,M) when is_list(Ks), is_map(M) ->
+ maps:from_list([{K,V}||{K,V} <- maps:to_list(M), not lists:member(K, Ks)]);
+without(Ks,M) ->
+ erlang:error(error_type(M),[Ks,M]).
-spec with(Ks, Map1) -> Map2 when
@@ -210,5 +215,11 @@ without(Ks, M) when is_list(Ks), is_map(M) ->
Map2 :: map(),
K :: term().
-with(Ks, M) when is_list(Ks), is_map(M) ->
- maps:from_list([{K,V}||{K,V} <- maps:to_list(M), lists:member(K, Ks)]).
+with(Ks,M) when is_list(Ks), is_map(M) ->
+ maps:from_list([{K,V}||{K,V} <- maps:to_list(M), lists:member(K, Ks)]);
+with(Ks,M) ->
+ erlang:error(error_type(M),[Ks,M]).
+
+
+error_type(M) when is_map(M) -> badarg;
+error_type(V) -> {badmap, V}.