diff options
Diffstat (limited to 'lib/stdlib/doc/src/maps.xml')
| -rw-r--r-- | lib/stdlib/doc/src/maps.xml | 68 |
1 files changed, 62 insertions, 6 deletions
diff --git a/lib/stdlib/doc/src/maps.xml b/lib/stdlib/doc/src/maps.xml index f766c843be..7345a9357a 100644 --- a/lib/stdlib/doc/src/maps.xml +++ b/lib/stdlib/doc/src/maps.xml @@ -33,6 +33,28 @@ <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> <desc> @@ -40,6 +62,9 @@ Returns a tuple <c>{ok, Value}</c> where <c><anno>Value</anno></c> is the value associated with <c><anno>Key</anno></c>, or <c>error</c> if no value is associated with <c><anno>Key</anno></c> in <c><anno>Map</anno></c>. </p> + <p> + The call will fail with a <c>{badmap,Map}</c> exception if <c><anno>Map</anno></c> is not a map. + </p> <p>Example:</p> <code type="none"> > Map = #{"hi" => 42}, @@ -95,8 +120,10 @@ <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 the call will - fail with an exception. + </p> + <p> + The call will fail with a <c>{badmap,Map}</c> exception if <c><anno>Map</anno></c> is not a map, + or with a <c>{badkey,Key}</c> exception if no value is associated with <c><anno>Key</anno></c>. </p> <p>Example:</p> <code type="none"> @@ -116,6 +143,10 @@ <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> + The call will fail with a <c>{badmap,Map}</c> exception if <c><anno>Map</anno></c> is not a map. + + </p> <p>Example:</p> <code type="none"> > Map = #{ key1 => val1, key2 => val2 }. @@ -134,7 +165,9 @@ val1 <p> Returns <c>true</c> if map <c><anno>Map</anno></c> contains <c><anno>Key</anno></c> and returns <c>false</c> if it does not contain the <c><anno>Key</anno></c>. - The function will fail with an exception if <c><anno>Map</anno></c> is not a Map. + </p> + <p> + The call will fail with a <c>{badmap,Map}</c> exception if <c><anno>Map</anno></c> is not a map. </p> <p>Example:</p> <code type="none"> @@ -154,6 +187,9 @@ false</code> <p> Returns a complete list of keys, in arbitrary order, which resides within <c><anno>Map</anno></c>. </p> + <p> + The call will fail with a <c>{badmap,Map}</c> exception if <c><anno>Map</anno></c> is not a map. + </p> <p>Example:</p> <code type="none"> > Map = #{42 => value_three,1337 => "value two","a" => 1}, @@ -189,6 +225,10 @@ false</code> Merges two maps into a single map <c><anno>Map3</anno></c>. If two keys exists in both maps the value in <c><anno>Map1</anno></c> will be superseded by the value in <c><anno>Map2</anno></c>. </p> + <p> + The call will fail with a <c>{badmap,Map}</c> exception if <c><anno>Map1</anno></c> or + <c><anno>Map2</anno></c> is not a map. + </p> <p>Example:</p> <code type="none"> > Map1 = #{a => "value_one", b => "value_two"}, @@ -222,6 +262,10 @@ false</code> replaced by value <c><anno>Value</anno></c>. The function returns a new map <c><anno>Map2</anno></c> containing the new association and the old associations 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. + </p> + <p>Example:</p> <code type="none"> > Map = #{"a" => 1}. @@ -241,6 +285,9 @@ false</code> The function removes the <c><anno>Key</anno></c>, if it exists, and its associated value from <c><anno>Map1</anno></c> and returns a new map <c><anno>Map2</anno></c> without key <c><anno>Key</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. + </p> <p>Example:</p> <code type="none"> > Map = #{"a" => 1}. @@ -276,6 +323,9 @@ false</code> The fuction returns a list of pairs representing the key-value associations of <c><anno>Map</anno></c>, where the pairs, <c>[{K1,V1}, ..., {Kn,Vn}]</c>, are returned in arbitrary order. </p> + <p> + The call will fail with a <c>{badmap,Map}</c> exception if <c><anno>Map</anno></c> is not a map. + </p> <p>Example:</p> <code type="none"> > Map = #{42 => value_three,1337 => "value two","a" => 1}, @@ -291,8 +341,11 @@ false</code> <p> If <c><anno>Key</anno></c> exists in <c><anno>Map1</anno></c> the old associated value is replaced by value <c><anno>Value</anno></c>. The function returns a new map <c><anno>Map2</anno></c> containing - the new associated value. If <c><anno>Key</anno></c> does not exist in <c><anno>Map1</anno></c> an exception is - generated. + the new associated value. + </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 a <c>{badkey,Key}</c> exception if no value is associated with <c><anno>Key</anno></c>. </p> <p>Example:</p> <code type="none"> @@ -308,7 +361,10 @@ false</code> <fsummary></fsummary> <desc> <p> - Returns a complete list of values, in arbitrary order, contained in map <c>M</c>. + Returns a complete list of values, in arbitrary order, contained in map <c>Map</c>. + </p> + <p> + The call will fail with a <c>{badmap,Map}</c> exception if <c><anno>Map</anno></c> is not a map. </p> <p>Example:</p> <code type="none"> |