From fc1967b11a65690c9ea8274c7c7fda94f7a338fa Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Bj=C3=B6rn-Egil=20Dahlberg?= <egil@erlang.org>
Date: Mon, 18 May 2015 10:19:24 +0200
Subject: stdlib: Document maps:filter/2

---
 lib/stdlib/doc/src/maps.xml | 22 ++++++++++++++++++++++
 1 file changed, 22 insertions(+)

diff --git a/lib/stdlib/doc/src/maps.xml b/lib/stdlib/doc/src/maps.xml
index e46068230a..7345a9357a 100644
--- a/lib/stdlib/doc/src/maps.xml
+++ b/lib/stdlib/doc/src/maps.xml
@@ -32,6 +32,28 @@
 	</description>
 	<funcs>
 
+		<func>
+			<name name="filter" arity="2"/>
+			<fsummary>Choose pairs which satisfy a predicate</fsummary>
+			<desc>
+				<p>
+                    Returns a map <c><anno>Map2</anno></c> for which predicate
+                    <c><anno>Pred</anno></c> holds true in <c><anno>Map1</anno></c>.
+				</p>
+				<p>
+                    The call will fail with a <c>{badmap,Map}</c> exception if
+                    <c><anno>Map1</anno></c> is not a map or with <c>badarg</c> if
+                    <c><anno>Pred</anno></c> is not a function of arity 2.
+				</p>
+				<p>Example:</p>
+				<code type="none">
+> M = #{a => 2, b => 3, c=> 4, "a" => 1, "b" => 2, "c" => 4},
+  Pred = fun(K,V) -> is_atom(K) andalso (V rem 2) =:= 0 end,
+  maps:filter(Pred,M).
+#{a => 2,c => 4} </code>
+			</desc>
+		</func>
+
 		<func>
 			<name name="find" arity="2"/>
 			<fsummary></fsummary>
-- 
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