PUSH-UNTOUCHABLE

add name or list of names to the list of untouchable symbols
Major Section:  EVENTS

Example:
(push-untouchable set-mem)

General Form: (push-untouchable name :doc doc-string) or (push-untouchable names :doc doc-string)

where name is a non-nil symbol or a true list of symbols and doc-string is an optional documentation string not beginning with ``:doc-section ...''. If name is a symbol it is treated as the singleton list containing that symbol. The effect of this event is to union the given symbols into the ``untouchables'' list in the current world. This event is redundant if every symbol listed is already a member of untouchables.

When a symbol is on the untouchables list it is syntactically illegal for any event to call a function of that name or to change the value of a state global variable of that name. Thus, the effect of pushing a function symbol, name, onto untouchables is to prevent any future event from using that symbol. This is generally done to ``fence off'' some primitive function symbol from ``users'' after the developer has used the symbol freely in the development of some higher level mechanism.