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authorBjörn-Egil Dahlberg <egil@erlang.org>2014-05-26 16:38:50 +0200
committerBjörn-Egil Dahlberg <egil@erlang.org>2014-05-26 16:38:50 +0200
commit6b6cd01b607a1bfcf61bb6d5f4cc3fe9b37445db (patch)
tree3e6200ef0f4c9563957daac8f14298faeb314094 /lib
parent6731d295915448e4c219f1db1b146264ced68018 (diff)
parent47463022cea3b7ca89124c1607cf10b92fbb536f (diff)
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Merge branch 'saa/add_default_value_for_maps_get/OTP-11951' into maint
* saa/add_default_value_for_maps_get/OTP-11951: stdlib: Fix indentation of maps doc Add docs and test for maps:get/3 Add default value for maps:get
Diffstat (limited to 'lib')
-rw-r--r--lib/stdlib/doc/src/maps.xml20
-rw-r--r--lib/stdlib/src/maps.erl18
-rw-r--r--lib/stdlib/test/Makefile3
-rw-r--r--lib/stdlib/test/maps_SUITE.erl69
4 files changed, 108 insertions, 2 deletions
diff --git a/lib/stdlib/doc/src/maps.xml b/lib/stdlib/doc/src/maps.xml
index 76137e3dee..b37f7fd7fd 100644
--- a/lib/stdlib/doc/src/maps.xml
+++ b/lib/stdlib/doc/src/maps.xml
@@ -108,6 +108,26 @@
</func>
<func>
+ <name name="get" arity="3"/>
+ <fsummary></fsummary>
+ <desc>
+ <p>
+ Returns the value <c><anno>Value</anno></c> associated with <c><anno>Key</anno></c> if
+ <c><anno>Map</anno></c> contains <c><anno>Key</anno></c>.
+ If no value is associated with <c><anno>Key</anno></c> then returns <c><anno>Default</anno></c>.
+ </p>
+ <p>Example:</p>
+ <code type="none">
+> Map = #{ key1 => val1, key2 => val2 }.
+#{key1 => val1,key2 => val2}
+> maps:get(key1, Map, "Default value").
+val1
+> maps:get(key3, Map, "Default value").
+"Default value"</code>
+ </desc>
+ </func>
+
+ <func>
<name name="is_key" arity="2"/>
<fsummary></fsummary>
<desc>
diff --git a/lib/stdlib/src/maps.erl b/lib/stdlib/src/maps.erl
index fd6d56fa47..4ef1638e6d 100644
--- a/lib/stdlib/src/maps.erl
+++ b/lib/stdlib/src/maps.erl
@@ -23,7 +23,8 @@
fold/3,
map/2,
size/1,
- without/2
+ without/2,
+ get/3
]).
@@ -142,6 +143,21 @@ 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) ->
+ case maps:find(Key, Map) of
+ {ok, Value} ->
+ Value;
+ error ->
+ Default
+ end.
+
+
-spec fold(Fun,Init,Map) -> Acc when
Fun :: fun((K, V, AccIn) -> AccOut),
Init :: term(),
diff --git a/lib/stdlib/test/Makefile b/lib/stdlib/test/Makefile
index 39f6ce423a..a271229c59 100644
--- a/lib/stdlib/test/Makefile
+++ b/lib/stdlib/test/Makefile
@@ -85,7 +85,8 @@ MODULES= \
zip_SUITE \
random_unicode_list \
random_iolist \
- error_logger_forwarder
+ error_logger_forwarder \
+ maps_SUITE
ERL_FILES= $(MODULES:%=%.erl)
diff --git a/lib/stdlib/test/maps_SUITE.erl b/lib/stdlib/test/maps_SUITE.erl
new file mode 100644
index 0000000000..c826ee731a
--- /dev/null
+++ b/lib/stdlib/test/maps_SUITE.erl
@@ -0,0 +1,69 @@
+%%
+%% %CopyrightBegin%
+%%
+%% Copyright Ericsson AB 1997-2014. All Rights Reserved.
+%%
+%% The contents of this file are subject to the Erlang Public License,
+%% Version 1.1, (the "License"); you may not use this file except in
+%% compliance with the License. You should have received a copy of the
+%% Erlang Public License along with this software. If not, it can be
+%% retrieved online at http://www.erlang.org/.
+%%
+%% Software distributed under the License is distributed on an "AS IS"
+%% basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
+%% the License for the specific language governing rights and limitations
+%% under the License.
+%%
+%% %CopyrightEnd%
+%%
+%%%----------------------------------------------------------------
+%%% Purpose: Test suite for the 'maps' module.
+%%%-----------------------------------------------------------------
+
+-module(maps_SUITE).
+
+-include_lib("test_server/include/test_server.hrl").
+
+% Default timetrap timeout (set in init_per_testcase).
+% This should be set relatively high (10-15 times the expected
+% max testcasetime).
+-define(default_timeout, ?t:minutes(4)).
+
+% Test server specific exports
+-export([all/0]).
+-export([suite/0]).
+-export([init_per_suite/1]).
+-export([end_per_suite/1]).
+-export([init_per_testcase/2]).
+-export([end_per_testcase/2]).
+
+-export([get3/1]).
+
+suite() ->
+ [{ct_hooks, [ts_install_cth]}].
+
+all() ->
+ [get3].
+
+init_per_suite(Config) ->
+ Config.
+
+end_per_suite(_Config) ->
+ ok.
+
+init_per_testcase(_Case, Config) ->
+ ?line Dog=test_server:timetrap(?default_timeout),
+ [{watchdog, Dog}|Config].
+
+end_per_testcase(_Case, Config) ->
+ Dog=?config(watchdog, Config),
+ test_server:timetrap_cancel(Dog),
+ ok.
+
+get3(Config) when is_list(Config) ->
+ Map = #{ key1 => value1, key2 => value2 },
+ DefaultValue = "Default value",
+ ?line value1 = maps:get(key1, Map, DefaultValue),
+ ?line value2 = maps:get(key2, Map, DefaultValue),
+ ?line DefaultValue = maps:get(key3, Map, DefaultValue),
+ ok.