Author: allison
Date: Fri Sep 14 13:37:17 2007
New Revision: 21298
Modified:
trunk/docs/pdds/draft/pdd17_pmc.pod
Log:
[pdd] Brushing away alternate timelines from PDD 17, and making cleanups.
Modified: trunk/docs/pdds/draft/pdd17_pmc.pod
==============================================================================
--- trunk/docs/pdds/draft/pdd17_pmc.pod (original)
+++ trunk/docs/pdds/draft/pdd17_pmc.pod Fri Sep 14 13:37:17 2007
@@ -48,10 +48,9 @@
All PMCs have the form:
struct PMC {
- UnionVal cache;
Parrot_UInt flags;
+ UnionVal cache;
VTABLE *vtable;
- PMC *real_self;
DPOINTER *data;
struct PMC_EXT *pmc_ext;
};
@@ -87,33 +86,8 @@
L<Vtable Functions> that implement the basic behaviour of the PMC
(i.e. how it behaves under addition, subtraction, cloning etc.)
-{{ PROPOSED:
-C<real_self> holds a pointer to the PMC that dynamically dispatched method
-calls should be made on. Normally this will be a pointer directly back to the
-PMC itself. However, in the case that the PMC has been subclassed by a non-PMC
-it will hold a pointer to the real object. This is so DYNSELF.method() style
-calls will dispatch correctly, calling any methods and/or v-table methods that
-have been overridden in PIR.
-
-AR: Problem is, not all low-level PMCs have a PMCProxy that could be stored in
-real_self to handle these method calls (they're only created when the subclass
-is created). So, rather than storing real_self for all PMCs, we should only
-store the delegator for objects that are delegated to (whether they're proxied
-or otherwise delegated).
-
-AR: Alternatively, this magic could all live in the PMCProxy: look up the
-method object, and then invoke it passing in the delegator as the invocant.
-(Not practical, because the code from the delegated class will expect to be
-poking into the internals of the object, but will have the wrong object.)
-Alternatively, we could say that PMCProxies must create PDD15 style storage for
-the delegated class. (Not practical, because the delegated class methods will
-expect to be poking into the internals of the object, but will have the wrong
-object.)
-
-}}
-
-C<data> (if present) holds a pointer to any additional data associated with
-the PMC. This may be NULL.
+C<data> holds a pointer to the core data associated with the PMC. This
+may be NULL.
C<pmc_ext> points to an extended PMC structure. This has the form:
@@ -123,8 +97,6 @@
PMC *_next_for_GC;
};
-C<data> is a generic data pointer, as described above.
-
C<_metadata> holds internal PMC metadata. The specification for this has not
yet been finalized.
@@ -145,7 +117,7 @@
PMCs are declared by the C<pmclass> keyword:
- pmclass <name> <modifiers> {
+ pmclass <name> [ <modifier> ... ] {
}
The modifiers specify core features, such as:
@@ -201,7 +173,8 @@
on how and where a PMC can be used.
Roles composed with C<does> may also define C<provides> for one or more
-interfaces.
+interfaces. (They generally define at least a C<provides> corresponding
+to their own name.)
=over 4
