Contents page

Index (83KB)

snap

   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.