Iterating over all atomicRanges widgets

v6
1

There are different ways of accessing properties of the state: memory efficient and via cursors/iterators.

How costly is it (internally) to go over 20-50 widgets every change/update using .iter ?

   const rangeSets = view.state.facet(EditorView.atomicRanges).map((f)=>f(view));
    for (let i=0; i<rangeSets.length; ++i) {
      if (rangeSets[i].size > 0) {
          const cursor = rangeSets[i].iter();
          let v;
          do {
            v = cursor.value;
            if (!v) break;
            //get some properties of v.widget...
            cursor.next();
          } while(v);
      }
    };

Or should I bypass facet method and go directly to values of editor view? I believe it is probably considered as a bad practice…

Thanks!

2

That should be absolutely fine.

And no, you really don’t want to reach into internal representations that aren’t documented. Those can change on any release.

1 Like
3

Thanks, @marijn !

Now I also noticed if I query atomicRanges from another view plugin during update or first creation the list is empty. Only if I trigger the request during viewport change, then there is something.

I though may be atomic ranges are not yet created, so I lowered the priority of my view plugin, which gets all atomic ranges widgets using Prec.lowest, however it did not help.

4

Can you set up a tiny example program that shows what you are doing precisely?

5

While I was setting up a minimal example in the playground, I had realized that it was mistake.
I was checking DOMElement of point decorations widgets, while during update/construction, but it is immediately available, since toDOM is delayed.

These are all related to the discussion An efficient way of decorating all parenthesis in a line - #4 by JerryI

This method

const rangeSets = view.state.facet(EditorView.atomicRanges).map((f)=>f(view))

in the end works perfectly combined with iterating over the existing syntax tree. I just defer the measurements of the DOM element offsetHeight, when they are available.

The result is fantastic!
it all also works nicely for the nested editors as well

Screenshot 2025-12-16 at 15.15.31
Screenshot 2025-12-16 at 15.15.311252×178 26.6 KB

Thanks for such efficient and robust architecture of CodeMirror 6. I bet it would not be possible with any other modular editor on the market :slight_smile: