^data^date
And you might not be able to change the permissions or date on the named stream either, since it may or may not have a separate date/permission thing from the container.You should be able to change the permission and data,
Sometimes you want the nonlocal effects and sometimes you don't, and by decomposing streams into smaller primitives we can let users choose as they want.but when you change it, you change it for the whole container.
Why? I'd much rather disallow it, than allow it and then have "nonlocal" effects.