$test_array = array("first_key" => "first_value",
                    "second_key" => "second_value");

var_dump(array_map(function($a, $b) { return "$a loves $b"; },
         array_keys($test_array),
         array_values($test_array)));

array(2) {
  [0]=>
  string(27) "first_key loves first_value"
  [1]=>
  string(29) "second_key loves second_value"
}

$test_array = array("first_key" => "first_value",
                    "second_key" => "second_value");
array_walk($test_array, function(&$a, $b) { $a = "$b loves $a"; });
var_dump($test_array);

$states = array('az' => 'Arizona', 'al' => 'Alabama');

array_map(function ($short, $long) {
    return array(
        'short' => $short,
        'long'  => $long
    );
}, array_keys($states), $states);

// produces:
array(
     array('short' => 'az', 'long' => 'Arizona'),
     array('short' => 'al', 'long' => 'Alabama')
)

$test_array = array("first_key" => "first_value",
                    "second_key" => "second_value");

var_dump(
    array_map(
        function($key) use ($test_array) { return "$key loves ${test_array[$key]}"; },
        array_keys($test_array)
    )
);

function array_map_assoc(callable $f, array $a) {
    return array_column(array_map($f, array_keys($a), $a), 1, 0);
}

$ordinals = [
    'first' => '1st',
    'second' => '2nd',
    'third' => '3rd',
];

$func = function ($k, $v) {
    return ['new ' . $k, 'new ' . $v];
};

var_dump(array_map_assoc($func, $ordinals));

array(3) {
  ["new first"]=>
  string(7) "new 1st"
  ["new second"]=>
  string(7) "new 2nd"
  ["new third"]=>
  string(7) "new 3rd"
}

function array_map_assoc_curried(callable $f) {
    return function (array $a) use ($f) {
        return array_column(array_map($f, array_keys($a), $a), 1, 0);
    };
}

...
$my_mapping = array_map_assoc_curried($func);
var_dump($my_mapping($ordinals));

function array_map_assoc(callable $f, array $a) {
    return array_merge(...array_map($f, array_keys($a), $a));
}

function array_map_assoc(callable $f, array $a) {
    return array_reduce(array_map($f, array_keys($a), $a), function (array $acc, array $a) {
        return $acc + $a;
    }, []);
}

$ordinals = [
    'first' => '1st',
    'second' => '2nd',
    'third' => '3rd',
];

$func = function ($k, $v) {
    return ['new ' . $k => 'new ' . $v];
};

var_dump(array_map_assoc($func, $ordinals));

$test_array = ["first_key" => "first_value",
               "second_key" => "second_value"];

$array_map_assoc = function (callable $f, array $a) {
    return array_column(array_map($f, array_keys($a), $a), 1, 0);
};

$f = function ($key, $value) {
    return [$key, $key . ' loves ' . $value];
};

var_dump(array_values($array_map_assoc($f, $test_array)));

$test_array = ["first_key" => "first_value",
               "second_key" => "second_value"];

$array_map_assoc = function (callable $f, array $a) {
    return array_map($f, array_keys($a), $a);
};

$f = function ($key, $value) {
    return $key . ' loves ' . $value;
};

var_dump($array_map_assoc($f, $test_array));

$test_array = array("first_key" => "first_value",
                    "second_key" => "second_value");

$result_array = array();
array_walk($test_array,
           function($a, $b) use (&$result_array)
           { $result_array[] = "$b loves $a"; },
           $result_array);
var_dump($result_array);

$mapped_array = from($test_array)
    ->select(function ($v, $k) { return "$k loves $v"; })
    ->toArray();

$mapped_iterator = from($test_array)->select('"$k loves $v"');

function map($array, callable $fn) {
  foreach ($array as $k => &$v) $v = call_user_func($fn, $k, $v);
  return $array;
}

function map($array, callable $fn = null) {
  return array_map($fn, array_keys($array), $array);
}

function array_map_($callback, $arr) {
    if (!is_callable($callback))
        return $arr;

    $result = array_walk($arr, function(&$value, $key) use ($callback) {
        $value = call_user_func($callback, $key, $value);
    });

    if (!$result)
        return false;

    return $arr;
}

$test_array = array("first_key" => "first_value",
                "second_key" => "second_value");

var_dump(array_map_(function($key, $value){
    return $key . " loves " . $value;
}, $arr));

array (
  'first_key' => 'first_key loves first_value,
  'second_key' => 'second_key loves second_value',
)

array_values(array_map_(function($key, $value){
    return $key . " loves " . $value;
}, $test_array))

function array_map_assoc(){
    if(func_num_args() < 2) throw new BadFuncionCallException('Missing parameters');

    $args = func_get_args();
    $callback = $args[0];

    if(!is_callable($callback)) throw new InvalidArgumentException('First parameter musst be callable');

    $arrays = array_slice($args, 1);

    array_walk($arrays, function(&$a){
        $a = (array)$a;
        reset($a);
    });

    $results = array();
    $max_length = max(array_map('count', $arrays));

    $arrays = array_map(function($pole) use ($max_length){
        return array_pad($pole, $max_length, null);
    }, $arrays);

    for($i=0; $i < $max_length; $i++){
        $elements = array();
        foreach($arrays as &$v){
            $elements[] = each($v);
        }
        unset($v);

        $out = call_user_func_array($callback, $elements);

        if($out === null) continue;

        $val = isset($out[1]) ? $out[1] : null;

        if(isset($out[0])){
            $results[$out[0]] = $val;
        }else{
            $results[] = $val;
        }
    }

    return $results;
}