public function isScalar()
    {
        return in_array($this->group(), [self::NUMBER, self::STRING, self::BOOL]);
    }
public function isScalar()
    {
        return in_array($this->group(), [self::NUMBER, self::STRING, self::BOOL]);
    }
public function isScalar ( ) { return in_array ( $ this -> group ( ) , [ self :: NUMBER , self :: STRING , self :: BOOL ] ) ; }
Return if this type is scalar.

@return bool
Return if this type is scalar .