Hi internals,
I finalized a new proposal for PHP. It consists into adding support for
package-private classes in the language.
A package private class is basically a class that can only be instantiated
in its declared namespace. This means that you cannot extend, implement or
use a class, interface or trait outside of declared namespace. It can be
referenced outside of the package, but instantiation can only be done there.
Other languages such as Java and C# consider package-private class as a
top-level class without any declared visibility. PHP cannot enforce this as
it would be an incredible BC break, but we can reuse an already declared
keyword "private" to fit this purpose. A class declared without any
visibility modifier is considered "public" and works exactly as it
currently does. The same applies to a class written with "public" keyword
(ie. public class Foo {}).
Most of checks are done at compile time and only instantiation is done at
runtime (the only place I found out it could be done). Performance impact
seems negligible as only one top condition is added during instantiation
bytecode executor.
At this stage I want to collect implementation feedback. Explanation is
done above and the extensive amount of tests self explains what the entire
purpose of this feature is. RFC will be created together with voting once
I'm able to gather some considerations.
Link to PR: https://github.com/php/php-src/pull/947
Cheers,
--
Guilherme Blanco
MSN: guilhermebla...@hotmail.com
GTalk: guilhermeblanco
Toronto - ON/Canada
