Seeking Reference Material on Certain Obscure Programming Terms

[Jeff Rush <jrush@xxxxxxxxxx>]

Hi, as I'm working through the Udanax Gold source, written in SmallTalk, 
I've come across some terms with which I'm unfamilar.  In some cases 
people have hand-waved a brief explanation but I'd like to research them 
further.  I've googled for them but haven't found much, as if the terms 
are very old programmer lore.  I've also searched two of the standard 
SmallTalk-80 books, from PARC, but no luck either.

* stepper
  obviously some kind of iterator; used as a base class in Udanax Gold
  but no definition of stepper is present; must be built-in to their
  flavor of SmallTalk.  There is some confusion over whether the
  collection over which we are iterating can be mutated or not; hints
  are that a stepper insulates the caller from mutations, which is
  uncommon in iterators in other languages (C++, Python).

* passe
  seems to be a method invoked on "self"; does it pass the call to
  the parent class, trigger an exception as "subclass must
  implement" or something else?  If the parent lacks such a method
  does it quietly do-nothing or raise an exception?

* fluid and emulsion
  apparently references to an old LISP object persistence mechanism
  that has found it's way into Udanax Gold/SmallTalk; I'm familar
  with the persistence mechanisms of Python (pickles) and CORBA,
  but I'd like to understand how fluid/emulsion compare.

Any explanatory URLs greatly appreciated!

Jeff Rush, A Xanadu Curator of
http://www.sunless-sea.net