(PECL ds >= 1.0.0)
Ds\Vector::rotate — Rotates the vector by a given number of rotations
    Rotates the vector by a given number of rotations, which is equivalent
    to successively calling $vector->push($vector->shift()) if the number
    of rotations is positive, or $vector->unshift($vector->pop()) if negative.
  
rotationsThe number of times the vector should be rotated.
没有返回值。. The vector of the current instance will be rotated.
示例 #1 Ds\Vector::rotate() example
<?php
$vector = new \Ds\Vector(["a", "b", "c", "d"]);
$vector->rotate(1);  // "a" is shifted, then pushed.
print_r($vector);
$vector->rotate(2);  // "b" and "c" are both shifted, the pushed.
print_r($vector);
?>以上示例的输出类似于:
(
    [0] => b
    [1] => c
    [2] => d
    [3] => a
)
Ds\Vector Object
(
    [0] => d
    [1] => a
    [2] => b
    [3] => c
)
