documents/userman/exthsusp.tex

36 The core feature is the ability to suspend the execution of a goal
50 % The suspend predicate
140 As a rule of thumb, goals will not suspend when all their arguments are
154 Instead of succeeding or failing, they will suspend when their arguments
173 suspend again. In the following example, the disequality predicate initially
188 all arguments are ground) can be found in the \libspec{suspend} library
189 \bipref{lib(suspend)}{../bips/lib/suspend/index.html}.
199 The solver will suspend these predicates until all their arguments
204 The suspend library is loaded into \eclipse\ on start-up, but the
205 constraints associated with the suspend solver are not imported.
206 To use them, either import the suspend library to the current module,
210 suspend:(X > 2), suspend:(X #=< 5)
397 \section{Explicit suspension with \predspec{suspend/3}}
404 \bipref{suspend/3}{../bips/kernel/suspensions/suspend-3.html}
406 \predspec{suspend/3} is itself based on the lower-level primitives
414 \predspec{suspend(\pattern{Goal}, \pattern{Prio}, \pattern{CondList})}
467 \bipref{suspend/3}{../bips/kernel/suspensions/suspend-3.html},
473             suspend(report_binding(X), 0, X->inst)
480 we explicitly suspend a goal with the condition that it be woken as
528 \label{suspend}
529 \index{suspend}
555 ?- suspend(writeln(woken(X)), 0, X->inst).
565 ?- suspend(writeln(woken(X)), 0, X->inst), X = 99.
575 ?- suspend(writeln(woken(X,Y)), 0, [X,Y]->inst), X = 99.
588 to act as a lazy test, we must let it suspend until both variables
593         ( var(X) -> suspend(succ_lazy(X,Y), 0, X->inst)
594         ; var(Y) -> suspend(succ_lazy(X,Y), 0, Y->inst)
613                 suspend(succ_eager(X,Y), 0, [X,Y]->inst)
622 Here, we suspend only in the case that both arguments are variables,
630 we re-suspend on one of the remaining variables. The following predicate
636             suspend(eval_lazy(Expr,Result), 0, Var->inst)
676                 suspend(succ_eager1(X,Y), 0, [X,Y]->bound)
742             suspend(report(X), 1, X->constrained)  % (re)suspend
787 \bipref{suspend/3}{../bips/kernel/suspensions/suspend-3.html}
803             suspend(report_ic(X), 1, [X->ic:min,X->ic:max,X->ic:hole])
848 in \bipref{suspend/3}{../bips/kernel/suspensions/suspend-3.html}
852 ?- suspend(writeln(woken), 0, trigger(happy)).
862 ?- suspend(writeln(woken), 0, trigger(happy)), trigger(happy).
895         to succeed or re-suspend.
972 \biprefni{suspend/3,4}{../bips/kernel/suspensions/suspend-3.html}\indextt{suspend/3}\indextt{suspend/4}
1102 insert_suspension(Vars, Susp, inst of suspend, suspend)
1106 list of the (system-predefined) \notation{suspend}
1135 \bipref{suspend/3}{../bips/kernel/suspensions/suspend-3.html}
1142 the suspend-attribute or by libraries like the interval solver library lib(ic).
1236       suspend(report1(X), 1, X->constrained).      % suspend
1241             suspend(report(X), 1, X->constrained)  % re-suspend
1252 easily referred to, because on every re-suspend a new suspension is created.
1278       suspend(report(X, Susp), 1, X->constrained, Susp).
1283           writeln(constrained(X))   % implicitly re-suspend
1345     suspend(report(Term),3,Term->inst).