HH\Lib\Keyset\map_with_key

Returns a new keyset where each value is the result of calling the given function on the original key and value

namespace HH\Lib\Keyset;

function map_with_key<Tk, Tv1, Tv2 as arraykey>(
  KeyedTraversable<Tk, Tv1> $traversable,
  (function(Tk, Tv1): Tv2) $value_func,
): keyset<Tv2>;

Time complexity: O(n * f), where f is the complexity of $value_func Space complexity: O(n)

Parameters

• KeyedTraversable<Tk,Tv1> $traversable
• (function(Tk, Tv1): Tv2) $value_func

Returns

• keyset<Tv2>

Examples

$result = Keyset\map_with_key(dict[1 => 2, 2 => 4, 3 => 5], ($key, $val) ==> $val*$key);
print_r($result);
//result: keyset[2,8,15]

$result = Keyset\map_with_key(dict[1 => 2, 2 => 4], ($key, $val) ==> $key);
print_r($result);
//result: keyset[1,2]