[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Name Change for Metaobject Protocol?

I'd like to suggest consideration of a name change for the metaobject
protocol. There were a number of occurances at OOPSLA which lead
me to think this may be a good idea. The one which stands out best
in my mind is Pierre Cointe's presentation at the CLOS working group,
where he presented an example of a metaclass (METAPOLYGON) which was
a metaclass in the Smalltalk sense, but not in the CLOS sense.
 From talking to other people, this misconception seemed widespread.

My understanding about what we mean by the metaobject or metaclass
protocol is a collection of classes and methods which can be used
to implement new object oriented languages or extend the semantics of the 
CLOS user level language, in a manner similar to the way macros can be used
to extend the syntax of Lisp. Additionally, one could look at the CLOS
metaclass protocol as a restricted version of Pattie Mais' reflection,
in the sense that it is a way of interrogating or modifying the language
semantics. What we do not mean is a class which acts as a "factory
instance" for creating and initializing classes, or a class which somehow
acts as a prototype (in the delegation sense) for other classes, though
one could use the metaobject protocol to define a metaclass which did

As start, I'd like to suggest two possible names. Once is macro protocol or 
semantic macro protocol, to draw an analogy with syntactic macros. The other is
reflective level protocol. The advantage of the first is that current Lisp
users will be able to make easy contact with it, the advantage of the
second is that it is perhaps more precise.

This issue may sound trivial, but, unfortunately, we are burdened with
history here, since Smalltalk and Objective-C have already appropriated
the name. While most Lisp programmers may not be bothered by this,
the confusion in OO circles is definitely there.