class Yaml
{
    /**
     * Очищаем Yaml строки от маркеров и комментариев в начале и в конце
     *
     * @param string $value The input YAML string
     *
     * @return string A cleaned up YAML string
     */
    private function cleanup($value)
    {
        $value = str_replace([("\r\n", "\r")], "\n", $value);
        // очищаем YAML шапку
        $value = preg_replace('#^\%YAML[: ][\d\.]+.*\n#u', '', $value);

        // удаляем комментарии
        $value = preg_replace('#^(\#.*?\n)+#s', '', $value);

        // удаляем маркер (---)
        $value = preg_replace('#^\-\-\-.*?\n#s', '', $value);

        // удаляем маркер (...)
        $value = preg_replace('#\.\.\.\s*$#', '', $value);
        return $value;
    }
    /**
     * массив из строк Yaml
     * @param $str
     * @return array
     */
    public function arrayLine($str)
    {

        $line = explode("\n", $str);

        foreach ($line as $val) {
            $yaml_dec[] = preg_replace('#^-#', ' ', $val);
        }

       //дальше нужно сделать разбор каждой строки
        $i = 0;
        foreach ($yaml_dec as $val) {
            $yaml_array [] = explode(":", $val);

            // если значение НЕ пустое
            if (!empty($yaml_array[$i][1])) {
                $var1[] = $yaml_array[$i][0];
                $var2[] = $yaml_array[$i][1];
            }
            $i++;
        }
        $yaml = array_combine($var1, $var2);

        return $yaml;
    }

    /**
     * получаем одномерный массив
     * @param $str
     * @return array
     */

    public function parser($str)
    {
        // очищаем и делаем массив
        $strline = $this->cleanup($str);
        return $this->arrayLine($strline);
    }
}

$yaml = <<<EOD
#sdjfhhsdjk
invoice: 34843
date: "2001-01-23"
bill-to: &id001
  given: Chris
  family: Dumars
  address:
    city: Royal Oak
    state: MI
    postal: 48046
ship-to: *id001
product:
- sku: BL394D
  quantity: 4
  description: Basketball
  price: 450
- sku: BL4438H
  quantity: 1
  description: Super Hoop
  price: 2392
tax: 251.420000
total: 4443.520000
comments: Late afternoon is best. Backup contact is Nancy Billsmer @ 338-4338.
...
EOD;

Array
(
    [invoice] =>  34843
    [date] =>  "2001-01-23"
    [bill-to] =>  &id001
    [  given] =>  Chris
    [  family] =>  Dumars
    [    city] =>  Royal Oak
    [    state] =>  MI
    [    postal] =>  48046
    [ship-to] =>  *id001
    [  sku] =>  BL4438H
    [  quantity] =>  1
    [  description] =>  Super Hoop
    [  price] =>  2392
    [tax] =>  251.420000
    [total] =>  4443.520000
    [comments] =>  Late afternoon is best. Backup contact is Nancy Billsmer @ 338-4338.
)