95 lines
2.6 KiB
C
95 lines
2.6 KiB
C
/************************************************************************
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** **
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** The YapTab/YapOr/OPTYap systems **
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** **
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** YapTab extends the Yap Prolog engine to support sequential tabling **
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** YapOr extends the Yap Prolog engine to support or-parallelism **
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** OPTYap extends the Yap Prolog engine to support or-parallel tabling **
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** **
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** **
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** Yap Prolog was developed at University of Porto, Portugal **
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** **
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************************************************************************/
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#ifdef SCCS
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static char SccsId[] = "%W% %G%";
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#endif /* SCCS */
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/************************************************************
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Unification Routines
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*************************************************************/
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static inline
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Int bind_variable(Term t0, Term t1)
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{
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tr_fr_ptr TR0 = TR;
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if (Yap_IUnify(t0,t1)) {
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return(TRUE);
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} else {
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while(TR != TR0) {
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CELL *p = (CELL *)TrailTerm(--TR);
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RESET_VARIABLE(p);
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}
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return(FALSE);
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}
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}
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EXTERN inline
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Int unify(Term t0, Term t1)
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{
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tr_fr_ptr TR0 = TR;
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if (Yap_IUnify(t0,t1)) {
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return(TRUE);
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} else {
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while(TR != TR0) {
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CELL *p = (CELL *)TrailTerm(--TR);
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RESET_VARIABLE(p);
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}
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return(FALSE);
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}
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}
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EXTERN inline Int unify_constant(register Term a, register Term cons)
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{
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CELL *pt;
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CELL *pt0, *pt1;
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deref_head(a,unify_cons_unk);
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unify_cons_nonvar:
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{
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if (a == cons) return(TRUE);
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else if (IsApplTerm(a) && IsExtensionFunctor(FunctorOfTerm(a))) {
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Functor fun = FunctorOfTerm(a);
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if (!IsApplTerm(cons) || FunctorOfTerm(cons) != fun)
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return FALSE;
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switch((CELL)fun) {
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case (CELL)FunctorDBRef:
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return(pt0 == pt1);
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case (CELL)FunctorLongInt:
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return(pt0[1] == pt1[1]);
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case (CELL)FunctorString:
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return(strcmp( (const char *)(pt0+2), (const char *)(pt1+2)) == 0);
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case (CELL)FunctorDouble:
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return(FloatOfTerm(AbsAppl(pt0)) == FloatOfTerm(AbsAppl(pt1)));
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#ifdef USE_GMP
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case (CELL)FunctorBigInt:
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return(Yap_gmp_tcmp_big_big(AbsAppl(pt0),AbsAppl(pt0)) == 0);
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#endif /* USE_GMP */
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default:
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return(FALSE);
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}
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}
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/* no other factors are accepted as arguments */
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return(FALSE);
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}
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deref_body(a,pt,unify_cons_unk,unify_cons_nonvar);
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YapBind(pt,cons);
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return(TRUE);
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}
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