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yap-6.3/OPTYap/or.sba_unify.h
2011-03-31 14:50:47 +01:00

87 lines
2.4 KiB
C

/************************************************************************
** **
** The YapTab/YapOr/OPTYap systems **
** **
** YapTab extends the Yap Prolog engine to support sequential tabling **
** YapOr extends the Yap Prolog engine to support or-parallelism **
** OPTYap extends the Yap Prolog engine to support or-parallel tabling **
** **
** **
** Yap Prolog was developed at University of Porto, Portugal **
** **
************************************************************************/
#ifdef SCCS
static char SccsId[] = "%W% %G%";
#endif /* SCCS */
/************************************************************
Unification Routines
*************************************************************/
static inline
Int bind_variable(Term t0, Term t1)
{
tr_fr_ptr TR0 = TR;
if (Yap_IUnify(t0,t1)) {
return(TRUE);
} else {
while(TR != TR0) {
CELL *p = (CELL *)TrailTerm(--TR);
RESET_VARIABLE(p);
}
return(FALSE);
}
}
EXTERN inline
/*
Int unify(Term t0, Term t1)
*/
Int unify(Term t0, Term t1)
{
tr_fr_ptr TR0 = TR;
if (Yap_IUnify(t0,t1)) {
return(TRUE);
} else {
while(TR != TR0) {
CELL *p = (CELL *)TrailTerm(--TR);
RESET_VARIABLE(p);
}
return(FALSE);
}
}
EXTERN inline Int unify_constant(register Term a, register Term cons)
{
CELL *pt;
deref_head(a,unify_cons_unk);
unify_cons_nonvar:
{
if (a == cons) return(TRUE);
else if (IsApplTerm(a) && IsExtensionFunctor(FunctorOfTerm(a))) {
Functor fun = FunctorOfTerm(a);
if (fun == FunctorDouble)
return(IsFloatTerm(cons) && FloatOfTerm(a) == FloatOfTerm(cons));
else if (fun == FunctorLongInt) {
return(IsLongIntTerm(cons) && LongIntOfTerm(a) == LongIntOfTerm(cons));
#ifdef TERM_EXTENSIONS
} else if (IsAttachFunc(fun)) {
return(attas[ExtFromFunctor(fun)].bind_op(SBIND,a,cons));
#endif /* TERM_EXTENSIONS */
} else
return(FALSE);
/* no other factors are accepted as arguments */
} else return(FALSE);
}
deref_body(a,pt,unify_cons_unk,unify_cons_nonvar);
Bind(pt,cons);
return(TRUE);
}