call/cc

call-with-current-continuation
call/cc

   <Lisp, programming> (call/cc) A {Lisp} control function that
   takes a function f as its argument and calls f, passing it the
   current {continuation}, which is itself a function, k.  k,
   which represents the context of the call to call/cc, takes the
   result of call/cc (which is the result of f) and returns the
   final result of the whole program.  Thus if, for example, the
   final result is to print the value returned by call/cc then
   anything passed to k will also be printed.

   E.g, in {Scheme}:

    (define (f k)
   	 (k 1)
   	 (k 2)
   	 3)

    (display (call-with-current-continuation f))

   Will display 1.

   (2001-04-27)