/**
* This method creates associative array using key and value functions on array elements.
*
* Example:
* <code>
* $array = range(1, 2);
* $map = Arrays::toMap($array, function ($elem) {
* return $elem * 10;
* }, function ($elem) {
* return $elem + 1;
* });
* </code>
* Result:
* <code>
* Array
* (
* [10] => 2
* [20] => 3
* )
* </code>
*
* @param array $elements
* @param callable $keyFunction
* @param callable|null $valueFunction
* @return array
*/
public static function toMap(array $elements, $keyFunction, $valueFunction = null)
{
if ($valueFunction == null) {
$valueFunction = Functions::identity();
}
$keys = array_map($keyFunction, $elements);
$values = array_map($valueFunction, $elements);
return empty($keys) ? array() : array_combine($keys, $values);
}
/**
* @test
*/
public function shouldNegatePredicate()
{
$this->assertFalse(Functions::call(Functions::not(Functions::identity()), true));
$this->assertTrue(Functions::call(Functions::not(Functions::identity()), false));
}
