call_stack - returns information about the functions involved in calling this function

array call_stack(int);

If the int argument is 0, call_stack() returns an array of the names of the
on the call stack, with the first one being the most recent (i.e. the
currently running program).  If the int argument is 1, call_stack returns
the objects in which that program is executing.  If it is 2, the name
of the functions are returned.  If it is 3, the value of origin() in that
frame is returned.

See also:
 previous_object,
 origin
