low tech MI

[Alan Bawden <Alan@lcs.mit.edu>]

   Date: Mon, 22 Apr 96 13:27:52 BST
   From: Jeff Dalton <jeff@aiai.ed.ac.uk>
   > MI is controversial [in the world of object-oriented programming]
   > chiefly because it introduces a lot of complexity (both semantic and
   > implementational) into method lookup.
   I'm not sure method lookup is the greatest problem.  A number of MI
   schemes have general MI method lookup but do something special, with
   restrictions, for slots....

True.  I thought about mentioning that when I composed my previous message,
but I decided that since that was primarily a -performance- problem, and I
couldn't imagine anybody arguing that accessing the slots of a condition
had to be single-memory-reference fast, I could get away with not
mentioning it.  Law number one of electronic mail design discussions must
be:

  Anything you decide not to mention in a message because it seems like it
  would just complicate your exposition, -will- be mentioned by somebody
  else in a follow-up message.

It is true that slot access under MI is not completely free of design
choices.  That is, of course, exactly why I sent out the code that I did
last night.