%%%%%%%%%%%         Forward chain for Hercule
%                   11.10.1997 12.05
:-[ru_com_h].
:-[ru_str_h].
:-[ru_mys_h].


/*
 * forward-chainer
 *   finds a production rule that can be fired,
 *   fires it, and informs the user, then calls
 *   itself to repeat the process.
*/

think :- 
	forall( rule(ID),
		pr_fired(ID)).
think:-fail.


pr_firing(N):- 
	 write('-------------------------------------->>>>  '),
	 write('Trying rule: '),
         write(N),nl.
	
pr_fired(N):- 
	 write('-------------------------------------->>>>  '),
	 write('Fired rule: '),
         write(N),nl.


/*
 * The remaining predicates are provided to make
 * writing and reading production rules easier.
 */

af(X) :- assert(fact(X)),  print('fact asserted :  '),write(X),nl.
rf(X) :- retract(fact(X)), print('fact removed :  '),write(X),nl.

ag(X) :- assert(goal(X)), print('goal asserted :  '),write(X),nl.
rg(X) :- retract(goal(X)), print('goal deleted :  '),write(X),nl.

afw(X) :- assert(fact(X)).
rfw(X) :- retract(fact(X)).

%I don't know what's that...
then.


:-nl,write('Consulting facts...'),nl,nl,consult('fact_h.pl').


%The cycle of reading
qloopread(Q):-
	write('>>>>>>>>>>>>>>>>>>>>>>>>>*****************************>>>>>>>>>>>>>>>>>>>>>>>>>'),nl,
	sleep(5),
	socket(ClientSocket),
	sock_writeln(ClientSocket,"page hercule &fact(stopread_herculog)"),
	sleep(1),
	repeat,
	  socket(ClientSocket),
	  sock_readln(ClientSocket,X),
%	  writt(X),
	  extrg(X,XG),
	  extra(X,XA),
	  not(ground(XA)),
	  extrf(X,XX),
	  (
	      ground(XX),remove_last(1,XX,XX1),name(XXC,XX1),
	      (
		  XXC='fact(stopread_herculog)', write('<<<<<<<<<<<<<<<<<<<<<<<<<*****************************<<<<<<<<<<<<<<<<<<<<<<<<<'),nl,!;
		  term_chars(X1,X),memansw(Q,X1)
	      );
	      fail
          ).
qloopread(Q):-fail.

writt(X):-
	not(X=[]),
	name(XX,X),
	write(XX),nl.
writt(X):-fail.

memansw(Q,X):-
	(fact(register_command(Q,A1,A2)),af(answ(A1,A2,X));
	 fact(register_command(Q,B1,B2,B3)),af(answ(B1,B2,B3,X));
	 fact(register_command(Q,C1,C2,C3,C4)),af(answ(C1,C2,C3,C4,X))).
memansw(_,_).

rfmemansw(Q):-
	(
	    fact(register_command(Q,A1,A2)),rfw(register_command(Q,A1,A2));
	    fact(register_command(Q,B1,B2,B3)),rfw(register_command(Q,B1,B2,B3));
	    fact(register_command(Q,C1,C2,C3,C4)),rfw(register_command(Q,C1,C2,C3,C4))).
rfmemansw(_).