Law of good style for CLOS

[karl lieberherr <lieber@corwin.ccs.northeastern.edu>]

Please can you forward this message to the CLOS community. -Thank you.

We have identified the following law of good style (known in-house
as the Law of Demeter) for CLOS programmers:

----------------------------------------------------------------
All generic function calls inside a method M must have
one of the following objects passed by their first argument:
    a value of M's parameters (including self) or
    an immediate part of self.

Objects created by the method and non-local objects
are viewed as being transmitted by arguments.
self is the name of the first argument of method M.
----------------------------------------------------------------

A paper on the Law of Demeter and its implications
will be presented at OOPSLA '88. For a short version, see IEEE Computer, 
June 88, Open Channel. We use a version of this Law which we can enforce 
efficiently at compile-time.

I am interested to know whether CLOS programmers are willing to
constrain themselves to follow this Law. I look forward to your feedback.

-- Karl Lieberherr