Sorry, this is not at all what I want. When I'm editing code in a language with curly braces, there is exactly one correct place for a line of code to be indented. In emacs, pressing tab puts my line of code in the right place. In BBEdit, it just inserts a tab.
I see what you're saying. That would indeed be a useful feature; I don't believe I've used an editor with such functionality (unless there's a shortcut in vim that does it?).