Major Section: SWITCHES-PARAMETERS-AND-MODES
Examples:
(push-untouchable my-var nil)
(push-untouchable set-mem t)
General Form:
(push-untouchable name{s} fn-p :doc doc-string)
where name{s} is a non-nil symbol or a non-nil true list of
symbols, fn-p is any value (but generally nil or t), and
doc-string is an optional documentation string not
beginning with ``:Doc-Section ...''. If name{s} 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 list of
``untouchable variables'' in the current world if fn-p is
nil, else to union the symbols into the list of ``untouchable
functions''. This event is redundant if every symbol listed is
already a member of the appropriate untouchables list (variables or
functions).When a symbol is on the untouchables list it is syntactically
illegal for any event to call a function or macro of that name, if
fn-p is non-nil, or to change the value of a state global
variable of that name, if fn-p is nil. Thus, the effect of
pushing a function symbol, name, onto untouchables is to prevent
any future event from using that symbol as a function or macro, or
as a state global variable (according to fn-p). 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.
Also see remove-untouchable.
