SqlParser\UtfString::getCharLength PHP Метод

    public static function getCharLength($byte)
    {
        $byte = ord($byte);
        if ($byte < 128) {
            return 1;
        } elseif ($byte < 224) {
            return 2;
        } elseif ($byte < 240) {
            return 3;
        } elseif ($byte < 248) {
            return 4;
        } elseif ($byte < 252) {
            return 5;
            // unofficial
        }
        return 6;
        // unofficial
    }

 public function testGetCharLength()
 {
     $this->assertEquals(1, UtfString::getCharLength(chr(0x0)));
     // 00000000
     $this->assertEquals(1, UtfString::getCharLength(chr(0x7f)));
     // 01111111
     $this->assertEquals(2, UtfString::getCharLength(chr(0xc0)));
     // 11000000
     $this->assertEquals(2, UtfString::getCharLength(chr(0xdf)));
     // 11011111
     $this->assertEquals(3, UtfString::getCharLength(chr(0xe0)));
     // 11100000
     $this->assertEquals(3, UtfString::getCharLength(chr(0xef)));
     // 11101111
     $this->assertEquals(4, UtfString::getCharLength(chr(0xf0)));
     // 11110000
     $this->assertEquals(4, UtfString::getCharLength(chr(0xf7)));
     // 11110111
     $this->assertEquals(5, UtfString::getCharLength(chr(0xf8)));
     // 11111000
     $this->assertEquals(5, UtfString::getCharLength(chr(0xfb)));
     // 11111011
     $this->assertEquals(6, UtfString::getCharLength(chr(0xfc)));
     // 11111100
     $this->assertEquals(6, UtfString::getCharLength(chr(0xfd)));
     // 11111101
 }