There's more going on here. They are adding a notion of "places" (what I would call "field paths") and an explicit syntax for "modes" (what I would call "privileges"). So you can now say:

    shared(x.a.b.c)

or:

    mut(y.d.e.f)

That makes it possible to pass around a reference with the promise that the callee will only access a subset of the fields of whatever referenced type you're talking about, as well as other things.

Superficially it looks very much like what I did in Regent [1] though I am sure the details differ widely.

[1]: https://regent-lang.org/tutorial/06_privileges/