gets backtrack point
integer(BackTrackPoint) (i) A value to be passed to cutbacktrack.
Together with cutbacktrack() ()
this predicate may be used to effect backtracking. Its effect is, that when
backtracking takes place back to the cutbacktrack() goal, the execution flow
takes a short-cut back to the position where the associated getbacktrack() goal
Instead of using getbacktrack() and cutbacktrack() you may also use set_cut () and cut () to achieve the same purpose. set_cut()/cut() are more comfortable in a way that you may use virtual handle, but they work sufficiently slower.
repeat, getbacktrack(BTP), for(1,5,X), write(X), X = 3, cutbacktrack(BTP), fail.
This will cause the following output:
A runtime error occurs if BackTrackPoint is bound. However, misuse may crash the system.
prolog-process, client-server, object
! , set_cut , cut , cutbacktrack