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yap-6.3/library/timeout.yap
Ulrich Neumerkel b38505cff2 FIXED: time_out output argument, exceptions (unhappy about once)
?- time_out(true,3600,time_out).
yes
   ?- catch(time_out(throw(x),3600,R),x,length(L,L)).
     ERROR!!
     UNHANDLED EXCEPTION - message time_out unknown
2009-05-19 23:58:35 -07:00

39 lines
1008 B
Prolog

/*************************************************************************
* *
* YAP Prolog *
* *
* Yap Prolog was developed at NCCUP - Universidade do Porto *
* *
* Copyright L.Damas, V.S.Costa and Universidade do Porto 1985-1997 *
* *
**************************************************************************
* *
* File: timeout.yap *
* Last rev: 5/12/99 *
* mods: *
* comments: Goal within timeout *
* *
*************************************************************************/
:- module(timeout, [
time_out/3
]).
:- meta_predicate time_out(:,+,-).
%
% not the nicest program I've ever seen.
%
time_out(Goal, Time, Result) :-
T is Time//1000,
UT is (Time mod 1000)*1000,
% enable alarm
alarm(T.UT,throw(time_out),_),
% launch goal and wait for signal
call_cleanup(
catch( ( Result0 = success, once(Goal) ),
time_out,
Result0 = time_out ),
alarm(0,_,_) ),
Result = Result0.