Hi!
I think infinite recursion is a potential issue for lots of logging setups ("let's log
when someone calls the logger!") and situations where you have multiple values to keep in
sync. The accessor implementation shouldn't try to solve these design problems.
The whole problem here is that the only reason why it is a problem is
because of the accessors that have hidden state in guards. If it were
regular variables (and for all the API consumer knows, they are) there
wouldn't be any question about if we're allowed to read $user->username
or not - if it's public, of course we can read it. So the problem exists
because the hidden state exists. It's not the problem of the code that
uses public APIs in completely legal way, it is the problem of our
implementation that we have hidden state that changes how variable
access works. With __get we mostly ignored it since recursion blocker
leads to the same result as if the variable did not exist - which is the
case for __get anyway, kind of - so it was less explicit. With accessors
it may become more painful.