bless

Synopsis:
   bless

Technical:
   The bless command allows an asynchronous atomic scope (eg, inside an
   on), to gain access to the local variables of an enclosing scope.
   Care must be taken to make sure that this command is only executed in a
   situation where this is an enclosing scope to gain access to.

   Normally when an "atomic scope" is invoked (an "atomic scope" is by
   definition an alias (or alias function) invocation or any asynchronous
   event (an on, a timer, a wait -cmd, a queue)), a new 
   stack frame is created and access to any local variables in previous
   stack frames is not allowed (because there is no guarantee just what 
   exactly is in the scope below us, so accessing their variables could be
   disastrous.)  However, in some cases, there is reasonable assurance that
   an atomic asynchronous scope will in fact be executed synchronously, and 
   that the previous stack is well-known, and that access to the local
   variables in that stack is desirable.  The semantics of this are straight-
   forward.  The enclosing (outer) scope must take some action to ensure that
   it will not "end", thus ending its stack frame, until the enclosed (inner)
   scope is done manipulating its local variables.  This is most often done
   by a wait command in the enclosing scope.  The enclosed scope then 
   would do a bless, and it would gain access to the local variables of
   the enclosing frame.  

   In general, this is re-entrant safe.  That is to say, the client keeps
   track of each stack as it is locked by wait, and matches it up with
   the each bless request, so that no matter how many times wait
   may be nested, it will be correctly matched up with each bless.

Practical:
   This is best demonstrated with an example:

	alias uh 
	{
		^local blahblah
		wait for {
			^userhost $* -cmd {
				bless
				push blahblah $3@$4
			}
		}
		return $blahblah
	}

See Also:
   wait(1); on(1); timer(1); queue(1)