Attributes on Classes, Fields and Methods

[leonerd]

How should attributes be implemented? They're attached to classes (that's an entirely new concept to perl), as well as fields and methods (which would be analogous to existing lexical variables and subroutines).

The existing implementation of core perl's attributes is hugely inadequate for what we're doing here, and suggests we need something much better. It also suggests a way that attributes can be extended and implemented in better ways in existing locations too, so these ideas aren't unique to the new classy locations.

In particular, we need much finer-grained ability to inject code into more occasions during compile and runtime. The way Object::Pad does it is that every kind of attribute has a vtable of function pointers associated with it, that are invoked at different times. It feels a bit like the MAGIC vtable.