The shortest DOM machine I have ever written [Not an Aprils Fool joke]

Hi,
Ok, today was an interesting day. Well yesterday
was also an interesting day , but I didn't want
to post a DOM machine on april fools day.
But yesterday I came up with:
function fiddle_out(data, buf) {
     let i = 0;
     let k = buf.indexOf("<", i);
     while (k !== -1) {
         let k2 = buf.indexOf(">", k+1);
         if (buf.charCodeAt(k+1) === 47) { // '/'
             data.insertAdjacentHTML("beforeend",
                   buf.substring(i, k));
             data = data.parentElement;
             i = k2+1;
             k = buf.indexOf("<", i);
         } else if (buf.charCodeAt(k2-1) !== 47) { // '/'
             data.insertAdjacentHTML("beforeend",
                   buf.substring(i, k2 + 1));
             data = data.lastElementChild;
             i = k2+1;
             k = buf.indexOf("<", i);
         } else {
             k = buf.indexOf("<", k2+1);
         }
     }
     data.insertAdjacentHTML("beforeend", buf.substring(i));
     return data;
}
And today I came up with the idea that fiddle_out
has not only data as an input argument, but also as
a return value. Namely the DOM cursor before and after.
My streams now have general understanding of
Sinks that are state machines. Every Sink can
be a state machine now, and modify this data.
Holy Cow!
Bye