Marcus Börger wrote:
> -> we have private, what about final, public, protected and
> abstract (can we remove/hide a method from an object)?
Do we in ZE2? What use it is?
In my book, private is only of very limited use, because there
always must be a way around it.
Introducing private (in C++) immediately called for the
introduction of protected and friend, with protected being a
mechanism to break privacy along the lines of the inheritance
hierarchy and friend being a mechanism to break privacy across
inheritance hierarchies, at compile time.
Since PHP does many things at run time which C++ does at compile
time, there must be a mechanism to break privacy at run time,
which makes it pretty pointless to have private variables in the
first place.
I'd rather go for a warning that is being triggered whenever I
access $a->_slot, but not when I access $this->_slot ("Access to
private object member"). I could suppress this warning by writing
$a->_slot as @$a->_slot instead.
Providing stronger privacy would only force the addition of even
more syntactic candy (such as a get_private($o, $slot) and
set_private($o, $slot)). Functions to break privacy are needed
in order to write Metafunctionality such as a serialization
agent, or a RPC proxy like the Soaping mixin class I introduced
in another mail to this list.
> -> do we allow to reduce visability (replace protected by
> private as long as we don't have it):
> class A {
> public function f()..
> }
> class B extends A {
> protected function f()...
> }
Same reasoning as above. Make it a warning, do not delve into B&D
language realms. PHP does things at run time, because we are in
the rapid prototyping area and flexibility comes before compile
type checking and static bindings. And anyway, class != type in
PHP.
Kristian
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