public function __construct($operation)
{
if (is_string($operation)) {
$operation = self::$operators[$operation];
}
$this->operator = $operation[0];
if (isset($operation[1])) {
$this->associativity = $operation[1];
$this->precedence = $operation[2];
$this->operandCount = isset($operation[3]) ? $operation[3] : 0;
}
}