snap

snap v.  To replace a pointer to a pointer with a direct
   pointer; to replace an old address with the forwarding address
   found there.  If you telephone the main number for an institution
   and ask for a particular person by name, the operator may tell you
   that person's extension before connecting you, in the hopes that
   you will `snap your pointer' and dial direct next time.  The
   underlying metaphor may be that of a rubber band stretched through
   a number of intermediate points; if you remove all the thumbtacks
   in the middle, it snaps into a straight line from first to last.
   See {chase pointers}.

   Often, the behavior of a {trampoline} is to perform an error
   check once and then snap the pointer that invoked it so as
   henceforth to bypass the trampoline (and its one-shot error check).
   In this context one also speaks of `snapping links'.  For
   example, in a LISP implementation, a function interface trampoline
   might check to make sure that the caller is passing the correct
   number of arguments; if it is, and if the caller and the callee are
   both compiled, then snapping the link allows that particular path
   to use a direct procedure-call instruction with no further
   overhead.