/************************************************************************* * * * YAP Prolog * * * * Yap Prolog was developed at NCCUP - Universidade do Porto * * * * Copyright L.Damas, V.S.Costa and Universidade do Porto 1985-1997 * * * ************************************************************************** * * * File: utilpreds.c * * Last rev: 4/03/88 * * mods: * * comments: new utility predicates for YAP * * * *************************************************************************/ #ifdef SCCS static char SccsId[] = "@(#)utilpreds.c 1.3"; #endif #include "Yap.h" #include "Yatom.h" #include "Heap.h" #include "yapio.h" #include "eval.h" #include "attvar.h" typedef struct { Term old_var; Term new_var; } *vcell; STATIC_PROTO(int copy_complex_term, (CELL *, CELL *, CELL *, CELL *)); STATIC_PROTO(CELL vars_in_complex_term, (CELL *, CELL *, Term)); STATIC_PROTO(Int p_non_singletons_in_term, (void)); STATIC_PROTO(CELL non_singletons_in_complex_term, (CELL *, CELL *)); STATIC_PROTO(Int p_variables_in_term, (void)); STATIC_PROTO(Int ground_complex_term, (CELL *, CELL *)); STATIC_PROTO(Int p_ground, (void)); STATIC_PROTO(Int p_copy_term, (void)); STATIC_PROTO(Int var_in_complex_term, (CELL *, CELL *, Term)); #ifdef DEBUG STATIC_PROTO(Int p_force_trail_expansion, (void)); #endif /* DEBUG */ static inline void clean_tr(tr_fr_ptr TR0) { if (TR != TR0) { do { Term p = TrailTerm(--TR); RESET_VARIABLE(p); } while (TR != TR0); } } static inline void clean_dirty_tr(tr_fr_ptr TR0) { if (TR != TR0) { tr_fr_ptr pt = TR0; do { Term p = TrailTerm(pt++); if (IsVarTerm(p)) { RESET_VARIABLE(p); } else { /* copy downwards */ TrailTerm(TR0+1) = TrailTerm(pt); TrailTerm(TR0) = TrailTerm(TR0+2) = p; pt+=2; TR0 += 3; } } while (pt != TR); TR = TR0; } } static int copy_complex_term(register CELL *pt0, register CELL *pt0_end, CELL *ptf, CELL *HLow) { CELL **to_visit0, **to_visit = (CELL **)Yap_PreAllocCodeSpace(); CELL *HB0 = HB; tr_fr_ptr TR0 = TR; #ifdef COROUTINING CELL *dvars = NULL; #endif HB = HLow; to_visit0 = to_visit; loop: while (pt0 < pt0_end) { register CELL d0; register CELL *ptd0; ++ pt0; ptd0 = pt0; d0 = *ptd0; deref_head(d0, copy_term_unk); copy_term_nvar: { if (IsPairTerm(d0)) { CELL *ap2 = RepPair(d0); if (ap2 >= HB && ap2 < H) { /* If this is newer than the current term, just reuse */ *ptf++ = d0; continue; } *ptf = AbsPair(H); ptf++; #ifdef RATIONAL_TREES if (to_visit + 4 >= (CELL **)AuxSp) { goto heap_overflow; } to_visit[0] = pt0; to_visit[1] = pt0_end; to_visit[2] = ptf; to_visit[3] = (CELL *)*pt0; /* fool the system into thinking we had a variable there */ *pt0 = AbsPair(H); to_visit += 4; #else if (pt0 < pt0_end) { if (to_visit + 3 >= (CELL **)AuxSp) { goto heap_overflow; } to_visit[0] = pt0; to_visit[1] = pt0_end; to_visit[2] = ptf; to_visit += 3; } #endif pt0 = ap2 - 1; pt0_end = ap2 + 1; ptf = H; H += 2; if (H > ASP - 2048) { goto overflow; } } else if (IsApplTerm(d0)) { register Functor f; register CELL *ap2; /* store the terms to visit */ ap2 = RepAppl(d0); if (ap2 >= HB && ap2 <= H) { /* If this is newer than the current term, just reuse */ *ptf++ = d0; continue; } f = (Functor)(*ap2); if (IsExtensionFunctor(f)) { { *ptf++ = d0; /* you can just copy other extensions. */ } continue; } *ptf = AbsAppl(H); ptf++; /* store the terms to visit */ #ifdef RATIONAL_TREES if (to_visit + 4 >= (CELL **)AuxSp) { goto heap_overflow; } to_visit[0] = pt0; to_visit[1] = pt0_end; to_visit[2] = ptf; to_visit[3] = (CELL *)*pt0; /* fool the system into thinking we had a variable there */ *pt0 = AbsAppl(H); to_visit += 4; #else if (pt0 < pt0_end) { if (to_visit + 3 >= (CELL **)AuxSp) { goto heap_overflow; } to_visit[0] = pt0; to_visit[1] = pt0_end; to_visit[2] = ptf; to_visit += 3; } #endif d0 = ArityOfFunctor(f); pt0 = ap2; pt0_end = ap2 + d0; /* store the functor for the new term */ H[0] = (CELL)f; ptf = H+1; H += 1+d0; if (H > ASP - 2048) { goto overflow; } } else { /* just copy atoms or integers */ *ptf++ = d0; } continue; } derefa_body(d0, ptd0, copy_term_unk, copy_term_nvar); if (ptd0 >= HLow && ptd0 < H) { /* we have already found this cell */ *ptf++ = (CELL) ptd0; } else { #if COROUTINING if (IsAttachedTerm((CELL)ptd0)) { /* if unbound, call the standard copy term routine */ CELL **bp[1]; if (dvars == NULL) { dvars = (CELL *)DelayTop(); } if (ptd0 >= dvars) { *ptf++ = (CELL) ptd0; } else { tr_fr_ptr CurTR; CurTR = TR; bp[0] = to_visit; HB = HB0; if (!attas[ExtFromCell(ptd0)].copy_term_op(ptd0, bp, ptf)) { goto overflow; } to_visit = bp[0]; HB = HLow; ptf++; Bind_Global(ptd0, ptf[-1]); } } else { #endif /* first time we met this term */ RESET_VARIABLE(ptf); Bind_Global(ptd0, (CELL)ptf); ptf++; #ifdef COROUTINING } #endif } } /* Do we still have compound terms to visit */ if (to_visit > to_visit0) { #ifdef RATIONAL_TREES to_visit -= 4; pt0 = to_visit[0]; pt0_end = to_visit[1]; ptf = to_visit[2]; *pt0 = (CELL)to_visit[3]; #else to_visit -= 3; pt0 = to_visit[0]; pt0_end = to_visit[1]; ptf = to_visit[2]; #endif goto loop; } /* restore our nice, friendly, term to its original state */ HB = HB0; clean_dirty_tr(TR0); return 0; overflow: /* oops, we're in trouble */ H = HLow; /* we've done it */ /* restore our nice, friendly, term to its original state */ HB = HB0; #ifdef RATIONAL_TREES while (to_visit > to_visit0) { to_visit -= 4; pt0 = to_visit[0]; pt0_end = to_visit[1]; ptf = to_visit[2]; *pt0 = (CELL)to_visit[3]; } #endif reset_trail(TR0); return -1; heap_overflow: /* oops, we're in trouble */ H = HLow; /* we've done it */ /* restore our nice, friendly, term to its original state */ HB = HB0; #ifdef RATIONAL_TREES while (to_visit > to_visit0) { to_visit -= 4; pt0 = to_visit[0]; pt0_end = to_visit[1]; ptf = to_visit[2]; *pt0 = (CELL)to_visit[3]; } #endif reset_trail(TR0); return -2; } static Term CopyTerm(Term inp, UInt arity) { Term t = Deref(inp); if (IsVarTerm(t)) { #if COROUTINING if (IsAttachedTerm(t)) { CELL *Hi; int res; restart_attached: *H = t; Hi = H+1; H += 2; if ((res = copy_complex_term(Hi-2, Hi-1, Hi, Hi)) < 0) { XREGS[arity+1] = t; H = Hi-1; if (res == -1) { /* handle overflow */ if (!Yap_gc(arity+1, ENV, P)) { Yap_Error(OUT_OF_STACK_ERROR, TermNil, Yap_ErrorMessage); return FALSE; } t = Deref(XREGS[arity+1]); goto restart_attached; } else { /* handle overflow */ if (!Yap_ExpandPreAllocCodeSpace(0,NULL)) { Yap_Error(OUT_OF_AUXSPACE_ERROR, TermNil, Yap_ErrorMessage); return FALSE; } t = Deref(XREGS[arity+1]); goto restart_attached; } } return(Hi[0]); } #endif return(MkVarTerm()); } else if (IsPrimitiveTerm(t)) { return(t); } else if (IsPairTerm(t)) { Term tf; CELL *ap; CELL *Hi; restart_list: ap = RepPair(t); Hi = H; tf = AbsPair(H); H += 2; { int res; if ((res = copy_complex_term(ap-1, ap+1, Hi, Hi)) < 0) { H = Hi; XREGS[arity+1] = t; if (res == -1) { /* handle overflow */ if (!Yap_gc(arity+1, ENV, P)) { Yap_Error(OUT_OF_STACK_ERROR, TermNil, Yap_ErrorMessage); return FALSE; } t = Deref(XREGS[arity+1]); goto restart_list; } else { /* handle overflow */ if (!Yap_ExpandPreAllocCodeSpace(0,NULL)) { Yap_Error(OUT_OF_AUXSPACE_ERROR, TermNil, Yap_ErrorMessage); return FALSE; } t = Deref(XREGS[arity+1]); goto restart_list; } } } return(tf); } else { Functor f = FunctorOfTerm(t); Term tf; CELL *HB0; CELL *ap; restart_appl: f = FunctorOfTerm(t); HB0 = H; ap = RepAppl(t); tf = AbsAppl(H); H[0] = (CELL)f; H += 1+ArityOfFunctor(f); { int res; if ((res = copy_complex_term(ap, ap+ArityOfFunctor(f), HB0+1, HB0)) < 0) { H = HB0; XREGS[arity+1] = t; if (res == -1) { if (!Yap_gc(arity+1, ENV, P)) { Yap_Error(OUT_OF_STACK_ERROR, TermNil, Yap_ErrorMessage); return FALSE; } t = Deref(XREGS[arity+1]); goto restart_appl; } else { /* handle overflow */ if (!Yap_ExpandPreAllocCodeSpace(0,NULL)) { Yap_Error(OUT_OF_AUXSPACE_ERROR, TermNil, Yap_ErrorMessage); return FALSE; } t = Deref(XREGS[arity+1]); goto restart_appl; } } } return(tf); } } Term Yap_CopyTerm(Term inp) { return CopyTerm(inp, 0); } static Int p_copy_term(void) /* copy term t to a new instance */ { Term t = CopyTerm(ARG1, 2); if (t == 0L) return FALSE; /* be careful, there may be a stack shift here */ return Yap_unify(ARG2,t); } static int copy_complex_term_no_delays(register CELL *pt0, register CELL *pt0_end, CELL *ptf, CELL *HLow) { CELL **to_visit0, **to_visit = (CELL **)Yap_PreAllocCodeSpace(); tr_fr_ptr TR0 = TR; CELL *HB0 = HB; HB = HLow; to_visit0 = to_visit; loop: while (pt0 < pt0_end) { register CELL d0; register CELL *ptd0; ++ pt0; ptd0 = pt0; d0 = *ptd0; deref_head(d0, copy_term_unk); copy_term_nvar: { if (IsPairTerm(d0)) { CELL *ap2 = RepPair(d0); if (ap2 >= HB && ap2 < H) { /* If this is newer than the current term, just reuse */ *ptf++ = d0; continue; } *ptf = AbsPair(H); ptf++; #ifdef RATIONAL_TREES if (to_visit + 4 >= (CELL **)AuxSp) { goto heap_overflow; } to_visit[0] = pt0; to_visit[1] = pt0_end; to_visit[2] = ptf; to_visit[3] = (CELL *)*pt0; /* fool the system into thinking we had a variable there */ *pt0 = AbsPair(H); to_visit += 4; #else if (pt0 < pt0_end) { if (to_visit + 3 >= (CELL **)AuxSp) { goto heap_overflow; } to_visit[0] = pt0; to_visit[1] = pt0_end; to_visit[2] = ptf; to_visit += 3; } #endif pt0 = ap2 - 1; pt0_end = ap2 + 1; ptf = H; H += 2; if (H > ENV - 2048) { goto overflow; } } else if (IsApplTerm(d0)) { register Functor f; register CELL *ap2; /* store the terms to visit */ ap2 = RepAppl(d0); if (ap2 >= HB && ap2 < H) { /* If this is newer than the current term, just reuse */ *ptf++ = d0; continue; } f = (Functor)(*ap2); if (IsExtensionFunctor(f)) { *ptf++ = d0; /* you can just copy other extensions. */ continue; } *ptf = AbsAppl(H); ptf++; /* store the terms to visit */ #ifdef RATIONAL_TREES if (to_visit + 4 >= (CELL **)AuxSp) { goto heap_overflow; } to_visit[0] = pt0; to_visit[1] = pt0_end; to_visit[2] = ptf; to_visit[3] = (CELL *)*pt0; /* fool the system into thinking we had a variable there */ *pt0 = AbsAppl(H); to_visit += 4; #else if (to_visit + 3 >= (CELL **)AuxSp) { goto heap_overflow; } if (pt0 < pt0_end) { to_visit[0] = pt0; to_visit[1] = pt0_end; to_visit[2] = ptf; to_visit += 3; } #endif d0 = ArityOfFunctor(f); pt0 = ap2; pt0_end = ap2 + d0; /* store the functor for the new term */ H[0] = (CELL)f; ptf = H+1; H += 1+d0; if (H > ENV - 2048) { goto overflow; } } else { /* just copy atoms or integers */ *ptf++ = d0; } continue; } derefa_body(d0, ptd0, copy_term_unk, copy_term_nvar); if (ptd0 >= HLow && ptd0 < H) { /* we have already found this cell */ *ptf++ = (CELL) ptd0; } else { /* first time we met this term */ RESET_VARIABLE(ptf); Bind_Global(ptd0, (CELL)ptf); ptf++; } } /* Do we still have compound terms to visit */ if (to_visit > to_visit0) { #ifdef RATIONAL_TREES to_visit -= 4; pt0 = to_visit[0]; pt0_end = to_visit[1]; ptf = to_visit[2]; *pt0 = (CELL)to_visit[3]; #else to_visit -= 3; pt0 = to_visit[0]; pt0_end = to_visit[1]; ptf = to_visit[2]; #endif goto loop; } /* we've done it */ /* restore our nice, friendly, term to its original state */ HB = HB0; clean_tr(TR0); return(0); overflow: /* oops, we're in trouble */ H = HLow; /* we've done it */ /* restore our nice, friendly, term to its original state */ HB = HB0; #ifdef RATIONAL_TREES while (to_visit > to_visit0) { to_visit -= 4; pt0 = to_visit[0]; pt0_end = to_visit[1]; ptf = to_visit[2]; *pt0 = (CELL)to_visit[3]; } #endif clean_tr(TR0); return(-1); heap_overflow: /* oops, we're in trouble */ H = HLow; /* we've done it */ /* restore our nice, friendly, term to its original state */ HB = HB0; #ifdef RATIONAL_TREES while (to_visit > to_visit0) { to_visit -= 4; pt0 = to_visit[0]; pt0_end = to_visit[1]; ptf = to_visit[2]; *pt0 = (CELL)to_visit[3]; } #endif clean_tr(TR0); return(-2); } static Term CopyTermNoDelays(Term inp) { Term t = Deref(inp); int res; if (IsVarTerm(t)) { return(MkVarTerm()); } else if (IsPrimitiveTerm(t)) { return(t); } else if (IsPairTerm(t)) { Term tf; CELL *ap, *Hi; restart_list: Hi = H; ap = RepPair(t); tf = AbsPair(H); H += 2; res = copy_complex_term_no_delays(ap-1, ap+1, H-2, H-2); if (res) { H = Hi; if (res == -1) { /* handle overflow */ if (!Yap_gc(2, ENV, P)) { Yap_Error(OUT_OF_STACK_ERROR, TermNil, Yap_ErrorMessage); return(FALSE); } t = Deref(ARG1); goto restart_list; } else { /* handle overflow */ if (!Yap_ExpandPreAllocCodeSpace(0,NULL)) { Yap_Error(OUT_OF_AUXSPACE_ERROR, TermNil, Yap_ErrorMessage); return(FALSE); } t = Deref(ARG1); goto restart_list; } } return(tf); } else { Functor f; Term tf; CELL *HB0; CELL *ap; restart_appl: f = FunctorOfTerm(t); HB0 = H; ap = RepAppl(t); tf = AbsAppl(H); H[0] = (CELL)f; H += 1+ArityOfFunctor(f); res = copy_complex_term_no_delays(ap, ap+ArityOfFunctor(f), HB0+1, HB0); if (res) { H = HB0; if (res == -1) { if (!Yap_gc(2, ENV, P)) { Yap_Error(OUT_OF_STACK_ERROR, TermNil, Yap_ErrorMessage); return(FALSE); } t = Deref(ARG1); goto restart_appl; } else { /* handle overflow */ if (!Yap_ExpandPreAllocCodeSpace(0,NULL)) { Yap_Error(OUT_OF_AUXSPACE_ERROR, TermNil, Yap_ErrorMessage); return(FALSE); } t = Deref(ARG1); goto restart_appl; } } return(tf); } } static Int p_copy_term_no_delays(void) /* copy term t to a new instance */ { Term t = CopyTermNoDelays(ARG1); if (t == 0L) { return FALSE; } /* be careful, there may be a stack shift here */ return(Yap_unify(ARG2,t)); } static Term vars_in_complex_term(register CELL *pt0, register CELL *pt0_end, Term inp) { register CELL **to_visit0, **to_visit = (CELL **)Yap_PreAllocCodeSpace(); register tr_fr_ptr TR0 = TR; CELL *InitialH = H; CELL output = AbsPair(H); to_visit0 = to_visit; loop: while (pt0 < pt0_end) { register CELL d0; register CELL *ptd0; ++ pt0; ptd0 = pt0; d0 = *ptd0; deref_head(d0, vars_in_term_unk); vars_in_term_nvar: { if (IsPairTerm(d0)) { #ifdef RATIONAL_TREES to_visit[0] = pt0; to_visit[1] = pt0_end; to_visit[2] = (CELL *)*pt0; to_visit += 3; *pt0 = TermNil; #else if (pt0 < pt0_end) { to_visit[0] = pt0; to_visit[1] = pt0_end; to_visit += 2; } #endif pt0 = RepPair(d0) - 1; pt0_end = RepPair(d0) + 1; } else if (IsApplTerm(d0)) { register Functor f; register CELL *ap2; /* store the terms to visit */ ap2 = RepAppl(d0); f = (Functor)(*ap2); if (IsExtensionFunctor(f)) { continue; } /* store the terms to visit */ #ifdef RATIONAL_TREES to_visit[0] = pt0; to_visit[1] = pt0_end; to_visit[2] = (CELL *)*pt0; to_visit += 3; *pt0 = TermNil; #else if (pt0 < pt0_end) { to_visit[0] = pt0; to_visit[1] = pt0_end; to_visit += 2; } #endif d0 = ArityOfFunctor(f); pt0 = ap2; pt0_end = ap2 + d0; } continue; } derefa_body(d0, ptd0, vars_in_term_unk, vars_in_term_nvar); /* do or pt2 are unbound */ *ptd0 = TermNil; /* leave an empty slot to fill in later */ H[1] = AbsPair(H+2); H += 2; H[-2] = (CELL)ptd0; /* next make sure noone will see this as a variable again */ TrailTerm(TR++) = (CELL)ptd0; } /* Do we still have compound terms to visit */ if (to_visit > to_visit0) { #ifdef RATIONAL_TREES to_visit -= 3; pt0 = to_visit[0]; pt0_end = to_visit[1]; *pt0 = (CELL)to_visit[2]; #else to_visit -= 2; pt0 = to_visit[0]; pt0_end = to_visit[1]; #endif goto loop; } clean_tr(TR0); Yap_ReleasePreAllocCodeSpace((ADDR)to_visit0); if (H != InitialH) { /* close the list */ Term t2 = Deref(inp); if (IsVarTerm(t2)) { RESET_VARIABLE(H-1); Yap_unify((CELL)(H-1),ARG2); } else { H[-1] = t2; /* don't need to trail */ } return(output); } else { return(inp); } } static Int p_variables_in_term(void) /* variables in term t */ { Term t = Deref(ARG1); Term out; if (IsVarTerm(t)) { out = AbsPair(H); H += 2; RESET_VARIABLE(H-2); RESET_VARIABLE(H-1); Yap_unify((CELL)(H-2),ARG1); Yap_unify((CELL)(H-1),ARG2); } else if (IsPrimitiveTerm(t)) out = ARG2; else if (IsPairTerm(t)) { out = vars_in_complex_term(RepPair(t)-1, RepPair(t)+1, ARG2); } else { Functor f = FunctorOfTerm(t); out = vars_in_complex_term(RepAppl(t), RepAppl(t)+ ArityOfFunctor(f), ARG2); } return(Yap_unify(ARG3,out)); } static Int p_term_variables(void) /* variables in term t */ { Term t = Deref(ARG1); Term out; if (IsVarTerm(t)) { return Yap_unify(MkPairTerm(t,TermNil), ARG2); } else if (IsPrimitiveTerm(t)) { return Yap_unify(TermNil, ARG2); } else if (IsPairTerm(t)) { out = vars_in_complex_term(RepPair(t)-1, RepPair(t)+1, TermNil); } else { Functor f = FunctorOfTerm(t); out = vars_in_complex_term(RepAppl(t), RepAppl(t)+ ArityOfFunctor(f), TermNil); } return Yap_unify(ARG2,out); } static Term non_singletons_in_complex_term(register CELL *pt0, register CELL *pt0_end) { register CELL **to_visit0, **to_visit = (CELL **)Yap_PreAllocCodeSpace(); register tr_fr_ptr TR0 = TR; CELL *InitialH = H; CELL output = AbsPair(H); to_visit0 = to_visit; loop: while (pt0 < pt0_end) { register CELL d0; register CELL *ptd0; ++ pt0; ptd0 = pt0; d0 = *ptd0; deref_head(d0, vars_in_term_unk); vars_in_term_nvar: { if (IsPairTerm(d0)) { if (to_visit + 1024 >= (CELL **)AuxSp) { goto aux_overflow; } #ifdef RATIONAL_TREES to_visit[0] = pt0; to_visit[1] = pt0_end; to_visit[2] = (CELL *)*pt0; to_visit += 3; *pt0 = TermNil; #else if (pt0 < pt0_end) { to_visit[0] = pt0; to_visit[1] = pt0_end; to_visit += 2; } #endif pt0 = RepPair(d0) - 1; pt0_end = RepPair(d0) + 1; } else if (IsApplTerm(d0)) { register Functor f; register CELL *ap2; /* store the terms to visit */ ap2 = RepAppl(d0); f = (Functor)(*ap2); if (IsExtensionFunctor(f)) { continue; } if (to_visit + 1024 >= (CELL **)AuxSp) { goto aux_overflow; } #ifdef RATIONAL_TREES to_visit[0] = pt0; to_visit[1] = pt0_end; to_visit[2] = (CELL *)*pt0; to_visit += 3; *pt0 = TermNil; #else /* store the terms to visit */ if (pt0 < pt0_end) { to_visit[0] = pt0; to_visit[1] = pt0_end; to_visit += 2; } #endif d0 = ArityOfFunctor(f); pt0 = ap2; pt0_end = ap2 + d0; } else if (d0 == TermFoundVar) { CELL *pt2 = pt0; while(IsVarTerm(*pt2)) pt2 = (CELL *)(*pt2); H[1] = AbsPair(H+2); H += 2; H[-2] = (CELL)pt2; *pt2 = TermReFoundVar; } continue; } derefa_body(d0, ptd0, vars_in_term_unk, vars_in_term_nvar); /* do or pt2 are unbound */ *ptd0 = TermFoundVar; /* next make sure we can recover the variable again */ TrailTerm(TR++) = (CELL)ptd0; } /* Do we still have compound terms to visit */ if (to_visit > to_visit0) { #ifdef RATIONAL_TREES to_visit -= 3; pt0 = to_visit[0]; pt0_end = to_visit[1]; *pt0 = (CELL)to_visit[2]; #else to_visit -= 2; pt0 = to_visit[0]; pt0_end = to_visit[1]; #endif goto loop; } clean_tr(TR0); if (H != InitialH) { /* close the list */ RESET_VARIABLE(H-1); Yap_unify((CELL)(H-1),ARG2); return output; } else { return ARG2; } aux_overflow: clean_tr(TR0); if (H != InitialH) { /* close the list */ RESET_VARIABLE(H-1); } return 0L; } static Int p_non_singletons_in_term(void) /* non_singletons in term t */ { Term t; Term out; while (TRUE) { t = Deref(ARG1); if (IsVarTerm(t)) { out = MkPairTerm(t,ARG2); } else if (IsPrimitiveTerm(t)) { out = ARG2; } else if (IsPairTerm(t)) { out = non_singletons_in_complex_term(RepPair(t)-1, RepPair(t)+1); } else { out = non_singletons_in_complex_term(RepAppl(t), RepAppl(t)+ ArityOfFunctor(FunctorOfTerm(t))); } if (out != 0L) { return Yap_unify(ARG3,out); } else { if (!Yap_ExpandPreAllocCodeSpace(0, NULL)) { Yap_Error(OUT_OF_AUXSPACE_ERROR, ARG1, "overflow in singletons"); return FALSE; } } } } static Int ground_complex_term(register CELL *pt0, register CELL *pt0_end) { register CELL **to_visit0, **to_visit = (CELL **)Yap_PreAllocCodeSpace(); to_visit0 = to_visit; loop: while (pt0 < pt0_end) { register CELL d0; register CELL *ptd0; ++pt0; ptd0 = pt0; d0 = *ptd0; deref_head(d0, vars_in_term_unk); vars_in_term_nvar: { if (IsPairTerm(d0)) { if (to_visit + 1024 >= (CELL **)AuxSp) { goto aux_overflow; } #ifdef RATIONAL_TREES to_visit[0] = pt0; to_visit[1] = pt0_end; to_visit[2] = (CELL *)*pt0; to_visit += 3; *pt0 = TermNil; #else if (pt0 < pt0_end) { to_visit[0] = pt0; to_visit[1] = pt0_end; to_visit += 2; } #endif pt0 = RepPair(d0) - 1; pt0_end = RepPair(d0) + 1; } else if (IsApplTerm(d0)) { register Functor f; register CELL *ap2; /* store the terms to visit */ ap2 = RepAppl(d0); f = (Functor)(*ap2); if (IsExtensionFunctor(f)) { continue; } if (to_visit + 1024 >= (CELL **)AuxSp) { goto aux_overflow; } #ifdef RATIONAL_TREES to_visit[0] = pt0; to_visit[1] = pt0_end; to_visit[2] = (CELL *)*pt0; to_visit += 3; *pt0 = TermNil; #else /* store the terms to visit */ if (pt0 < pt0_end) { to_visit[0] = pt0; to_visit[1] = pt0_end; to_visit += 2; } #endif d0 = ArityOfFunctor(f); pt0 = ap2; pt0_end = ap2 + d0; } continue; } derefa_body(d0, ptd0, vars_in_term_unk, vars_in_term_nvar); #ifdef RATIONAL_TREES while (to_visit > to_visit0) { to_visit -= 3; pt0 = to_visit[0]; pt0_end = to_visit[1]; *pt0 = (CELL)to_visit[2]; } #endif return FALSE; } /* Do we still have compound terms to visit */ if (to_visit > to_visit0) { #ifdef RATIONAL_TREES to_visit -= 3; pt0 = to_visit[0]; pt0_end = to_visit[1]; *pt0 = (CELL)to_visit[2]; #else to_visit -= 2; pt0 = to_visit[0]; pt0_end = to_visit[1]; #endif goto loop; } return TRUE; aux_overflow: /* unwind stack */ #ifdef RATIONAL_TREES while (to_visit > to_visit0) { to_visit -= 3; pt0 = to_visit[0]; pt0_end = to_visit[1]; *pt0 = (CELL)to_visit[2]; } #endif return -1; } static Int p_ground(void) /* ground(+T) */ { Term t; while (TRUE) { Int out; t = Deref(ARG1); if (IsVarTerm(t)) { return FALSE; } else if (IsPrimitiveTerm(t)) { return TRUE; } else if (IsPairTerm(t)) { if ((out =ground_complex_term(RepPair(t)-1, RepPair(t)+1)) >= 0) { return out; } } else { Functor fun = FunctorOfTerm(t); if (IsExtensionFunctor(fun)) return(TRUE); else if ((out = ground_complex_term(RepAppl(t), RepAppl(t)+ ArityOfFunctor(fun))) >= 0) { return out; } } if (out < 0) { if (!Yap_ExpandPreAllocCodeSpace(0, NULL)) { Yap_Error(OUT_OF_AUXSPACE_ERROR, ARG1, "overflow in ground"); return FALSE; } } } } static Int var_in_complex_term(register CELL *pt0, register CELL *pt0_end, Term v) { register CELL **to_visit0, **to_visit = (CELL **)Yap_PreAllocCodeSpace(); register tr_fr_ptr TR0 = TR; to_visit0 = to_visit; loop: while (pt0 < pt0_end) { register CELL d0; register CELL *ptd0; ++ pt0; ptd0 = pt0; d0 = *ptd0; deref_head(d0, var_in_term_unk); var_in_term_nvar: { if (IsPairTerm(d0)) { #ifdef RATIONAL_TREES to_visit[0] = pt0; to_visit[1] = pt0_end; to_visit[2] = (CELL *)*pt0; to_visit += 3; *pt0 = TermNil; #else if (pt0 < pt0_end) { to_visit[0] = pt0; to_visit[1] = pt0_end; to_visit += 2; } #endif pt0 = RepPair(d0) - 1; pt0_end = RepPair(d0) + 1; } else if (IsApplTerm(d0)) { register Functor f; register CELL *ap2; /* store the terms to visit */ ap2 = RepAppl(d0); f = (Functor)(*ap2); if (IsExtensionFunctor(f)) { continue; } #ifdef RATIONAL_TREES to_visit[0] = pt0; to_visit[1] = pt0_end; to_visit[2] = (CELL *)*pt0; to_visit += 3; *pt0 = TermNil; #else /* store the terms to visit */ if (pt0 < pt0_end) { to_visit[0] = pt0; to_visit[1] = pt0_end; to_visit += 2; } #endif d0 = ArityOfFunctor(f); pt0 = ap2; pt0_end = ap2 + d0; } continue; } deref_body(d0, ptd0, var_in_term_unk, var_in_term_nvar); if ((CELL)ptd0 == v) { /* we found it */ clean_tr(TR0); return(TRUE); } /* do or pt2 are unbound */ *ptd0 = TermNil; /* next make sure noone will see this as a variable again */ TrailTerm(TR++) = (CELL)ptd0; } /* Do we still have compound terms to visit */ if (to_visit > to_visit0) { #ifdef RATIONAL_TREES to_visit -= 3; pt0 = to_visit[0]; pt0_end = to_visit[1]; *pt0 = (CELL)to_visit[2]; #else to_visit -= 2; pt0 = to_visit[0]; pt0_end = to_visit[1]; #endif goto loop; } clean_tr(TR0); return FALSE; } static Int var_in_term(Term v, Term t) /* variables in term t */ { if (IsVarTerm(t)) { return(v == t); } else if (IsPrimitiveTerm(t)) { return(FALSE); } else if (IsPairTerm(t)) { return(var_in_complex_term(RepPair(t)-1, RepPair(t)+1, v)); } else return(var_in_complex_term(RepAppl(t), RepAppl(t)+ ArityOfFunctor(FunctorOfTerm(t)),v)); } static Int p_var_in_term(void) { return(var_in_term(Deref(ARG2), Deref(ARG1))); } /* The code for TermHash was originally contributed by Gertjen Van Noor */ /* This code with max_depth == -1 will loop for infinite trees */ #define GvNht ((UInt *)H) #define HASHADD(T) (GvNht[k]+=(T), k=(k<2 ? k+1 : 0)) static Int TermHash(Term t1, Int depth_lim, Int k) { Int i; if (IsVarTerm(t1)) { return(-1); } else if (IsAtomTerm(t1)) { register char *s = AtomName(AtomOfTerm(t1)); for (i=0; s[i]; i++) HASHADD(s[i]); return(k); } else if (IsPairTerm(t1)) { HASHADD('.'); depth_lim--; if (depth_lim == 0) return(TRUE); k = TermHash(HeadOfTerm(t1),depth_lim,k); if (k < 0) return(-1); k = TermHash(TailOfTerm(t1),depth_lim,k); return(k); } else if (IsIntTerm(t1)) { HASHADD(IntOfTerm(t1)); return(k); } else { Functor f = FunctorOfTerm(t1); if (IsExtensionFunctor(f)) { if (f == FunctorDouble) { Int *iptr = (Int *)(RepAppl(t1)+1); int i; for (i = 0; i < sizeof(Float) / sizeof(CELL); i++) { HASHADD(*iptr++); } return(k); } else if (f == FunctorLongInt) { HASHADD(LongIntOfTerm(t1)); return(k); } else if (f == FunctorDBRef) { HASHADD((Int)DBRefOfTerm(t1)); return(k); /* should never happen */ } else { return(-1); } } else { int ar = ArityOfFunctor(FunctorOfTerm(t1)); int res = TRUE; register char *s = AtomName(NameOfFunctor(f)); depth_lim--; if (depth_lim == 0) return(TRUE); for (i=0; s[i]; i++) HASHADD(s[i]); for (i=1; i<=ar && res; i++) { k = TermHash(ArgOfTerm(i,t1),depth_lim,k); if (k == -1 ) return(-1); } return(k); } } } static Int GvNTermHash(void) { unsigned int i1,i2,i3; Term t1 = Deref(ARG1); Term t2 = Deref(ARG2); Term t3 = Deref(ARG3); Term result; Int size, depth; if (IsVarTerm(t2)) { Yap_Error(INSTANTIATION_ERROR,t2,"term_hash/4"); return(FALSE); } if (!IsIntegerTerm(t2)) { Yap_Error(TYPE_ERROR_INTEGER,t2,"term_hash/4"); return(FALSE); } depth = IntegerOfTerm(t2); if (depth == 0) { if (IsVarTerm(t1)) return(TRUE); return(Yap_unify(ARG4,MkIntTerm(0))); } if (IsVarTerm(t3)) { Yap_Error(INSTANTIATION_ERROR,t3,"term_hash/4"); return(FALSE); } if (!IsIntegerTerm(t3)) { Yap_Error(TYPE_ERROR_INTEGER,t3,"term_hash/4"); return(FALSE); } size = IntegerOfTerm(t3); GvNht[0] = 0; GvNht[1] = 0; GvNht[2] = 0; if (TermHash(t1,depth,0) == -1) return(TRUE); i1 = GvNht[0]; i2 = GvNht[1]; i3 = GvNht[2]; i2 ^= i3; i1 ^= i2; i1 = (((i3 << 7) + i2) << 7) + i1; result = MkIntegerTerm(i1 % size); return Yap_unify(ARG4,result); } static int variant_complex(register CELL *pt0, register CELL *pt0_end, register CELL *pt1) { tr_fr_ptr OLDTR = TR; register CELL **to_visit = (CELL **)ASP; /* make sure that unification always forces trailing */ HBREG = H; loop: while (pt0 < pt0_end) { register CELL d0, d1; ++ pt0; ++ pt1; d0 = Derefa(pt0); d1 = Derefa(pt1); if (IsVarTerm(d0)) { if (IsVarTerm(d1)) { CELL *pt0 = VarOfTerm(d0); CELL *pt1 = VarOfTerm(d1); if (pt0 >= HBREG || pt1 >= HBREG) { /* one of the variables has been found before */ if (VarOfTerm(d0)+1 == VarOfTerm(d1)) continue; goto fail; } else { /* two new occurrences of the same variable */ Term n0 = MkVarTerm(), n1 = MkVarTerm(); Bind_Global(VarOfTerm(d0), n0); Bind_Global(VarOfTerm(d1), n1); } continue; } else { goto fail; } } else if (IsVarTerm(d1)) { goto fail; } else { if (d0 == d1) continue; else if (IsAtomOrIntTerm(d0)) { goto fail; } else if (IsPairTerm(d0)) { if (!IsPairTerm(d1)) { goto fail; } #ifdef RATIONAL_TREES /* now link the two structures so that no one else will */ /* come here */ to_visit -= 4; if ((CELL *)to_visit < H+1024) goto out_of_stack; to_visit[0] = pt0; to_visit[1] = pt0_end; to_visit[2] = pt1; to_visit[3] = (CELL *)*pt0; *pt0 = d1; #else /* store the terms to visit */ if (pt0 < pt0_end) { to_visit -= 3; if ((CELL *)to_visit < H+1024) goto out_of_stack; to_visit[0] = pt0; to_visit[1] = pt0_end; to_visit[2] = pt1; } #endif pt0 = RepPair(d0) - 1; pt0_end = RepPair(d0) + 1; pt1 = RepPair(d1) - 1; continue; } else if (IsApplTerm(d0)) { register Functor f; register CELL *ap2, *ap3; if (!IsApplTerm(d1)) { goto fail; } else { /* store the terms to visit */ Functor f2; ap2 = RepAppl(d0); ap3 = RepAppl(d1); f = (Functor)(*ap2); f2 = (Functor)(*ap3); if (f != f2) goto fail; if (IsExtensionFunctor(f)) { if (!unify_extension(f, d0, ap2, d1)) goto fail; continue; } #ifdef RATIONAL_TREES /* now link the two structures so that no one else will */ /* come here */ to_visit -= 4; if ((CELL *)to_visit < H+1024) goto out_of_stack; to_visit[0] = pt0; to_visit[1] = pt0_end; to_visit[2] = pt1; to_visit[3] = (CELL *)*pt0; *pt0 = d1; #else /* store the terms to visit */ if (pt0 < pt0_end) { to_visit -= 3; if ((CELL *)to_visit < H+1024) goto out_of_stack; to_visit[0] = pt0; to_visit[1] = pt0_end; to_visit[2] = pt1; } #endif d0 = ArityOfFunctor(f); pt0 = ap2; pt0_end = ap2 + d0; pt1 = ap3; continue; } } } } /* Do we still have compound terms to visit */ if (to_visit < (CELL **)ASP) { #ifdef RATIONAL_TREES pt0 = to_visit[0]; pt0_end = to_visit[1]; pt1 = to_visit[2]; *pt0 = (CELL)to_visit[3]; to_visit += 4; #else pt0 = to_visit[0]; pt0_end = to_visit[1]; pt1 = to_visit[2]; to_visit += 3; #endif goto loop; } H = HBREG; /* untrail all bindings made by variant */ while (TR != (tr_fr_ptr)OLDTR) { CELL *pt1 = (CELL *) TrailTerm(--TR); RESET_VARIABLE(pt1); } HBREG = B->cp_h; return TRUE; out_of_stack: H = HBREG; /* untrail all bindings made by variant */ #ifdef RATIONAL_TREES while (to_visit < (CELL **)ASP) { pt0 = to_visit[0]; pt0_end = to_visit[1]; pt1 = to_visit[2]; *pt0 = (CELL)to_visit[3]; to_visit += 4; } #endif while (TR != (tr_fr_ptr)OLDTR) { CELL *pt1 = (CELL *) TrailTerm(--TR); RESET_VARIABLE(pt1); } HBREG = B->cp_h; return -1; fail: /* failure */ H = HBREG; #ifdef RATIONAL_TREES while (to_visit < (CELL **)ASP) { pt0 = to_visit[0]; pt0_end = to_visit[1]; pt1 = to_visit[2]; *pt0 = (CELL)to_visit[3]; to_visit += 4; } #endif /* untrail all bindings made by variant */ while (TR != (tr_fr_ptr)OLDTR) { CELL *pt1 = (CELL *) TrailTerm(--TR); RESET_VARIABLE(pt1); } HBREG = B->cp_h; return FALSE; } static Int p_variant(void) /* variant terms t1 and t2 */ { Term t1 = Deref(ARG1); Term t2 = Deref(ARG2); int out; if (t1 == t2) return (TRUE); if (IsVarTerm(t1)) { if (IsVarTerm(t2)) return(TRUE); return(FALSE); } else if (IsVarTerm(t2)) return(FALSE); if (IsAtomOrIntTerm(t1)) { return(t1 == t2); } if (IsPairTerm(t1)) { if (IsPairTerm(t2)) { out = variant_complex(RepPair(t1)-1, RepPair(t1)+1, RepPair(t2)-1); if (out < 0) goto error; return out; } else return (FALSE); } if (!IsApplTerm(t2)) { return FALSE; } else { Functor f1 = FunctorOfTerm(t1); if (f1 != FunctorOfTerm(t2)) return(FALSE); if (IsExtensionFunctor(f1)) { return(unify_extension(f1, t1, RepAppl(t1), t2)); } out = variant_complex(RepAppl(t1), RepAppl(t1)+ArityOfFunctor(f1), RepAppl(t2)); if (out < 0) goto error; return out; } error: if (out == -1) { if (!Yap_gc(2, ENV, P)) { Yap_Error(OUT_OF_STACK_ERROR, TermNil, "in variant"); return FALSE; } return p_variant(); } return FALSE; } static int subsumes_complex(register CELL *pt0, register CELL *pt0_end, register CELL *pt1) { register CELL **to_visit = (CELL **)ASP; tr_fr_ptr OLDTR = TR, new_tr; UInt write_mode = TRUE; HBREG = H; loop: while (pt0 < pt0_end) { register CELL d0, d1; Int our_write_mode = write_mode; ++ pt0; ++ pt1; /* this is a version of Derefa that checks whether we are trying to do something evil */ { CELL *npt0 = pt0; restart_d0: if (npt0 >= HBREG) { our_write_mode = FALSE; } d0 = *npt0; if (IsVarTerm(d0) && d0 != (CELL)npt0 ) { npt0 = (CELL *)d0; goto restart_d0; } } { CELL *npt1 = pt1; restart_d1: d1 = *npt1; if (IsVarTerm(d1) && d1 != (CELL)npt1 ) { /* never dereference through a variable from the left-side */ if (npt1 >= HBREG) { goto fail; } else { npt1 = (CELL *)d1; goto restart_d1; } } } if (IsVarTerm(d0)) { if (our_write_mode) { /* generate a new binding */ CELL *pt0 = VarOfTerm(d0); Term new = MkVarTerm(); Bind_Global(pt0, new); if (d0 != d1) { /* avoid loops */ Bind_Global(VarOfTerm(new), d1); } } else { if (d0 == d1) continue; goto fail; } continue; } else if (IsVarTerm(d1)) { goto fail; } else { if (d0 == d1) continue; else if (IsAtomOrIntTerm(d0)) { goto fail; } else if (IsPairTerm(d0)) { if (!IsPairTerm(d1)) { goto fail; } #ifdef RATIONAL_TREES /* now link the two structures so that no one else will */ /* come here */ to_visit -= 5; to_visit[0] = pt0; to_visit[1] = pt0_end; to_visit[2] = pt1; to_visit[3] = (CELL *)*pt0; to_visit[4] = (CELL *)write_mode; *pt0 = d1; #else /* store the terms to visit */ if (pt0 < pt0_end) { to_visit -= 4; to_visit[0] = pt0; to_visit[1] = pt0_end; to_visit[2] = pt1; to_visit[3] = (CELL *)write_mode; } #endif write_mode = our_write_mode; pt0 = RepPair(d0) - 1; pt0_end = RepPair(d0) + 1; pt1 = RepPair(d1) - 1; continue; } else if (IsApplTerm(d0)) { register Functor f; register CELL *ap2, *ap3; if (!IsApplTerm(d1)) { goto fail; } else { /* store the terms to visit */ Functor f2; ap2 = RepAppl(d0); ap3 = RepAppl(d1); f = (Functor)(*ap2); f2 = (Functor)(*ap3); if (f != f2) goto fail; if (IsExtensionFunctor(f)) { if (!unify_extension(f, d0, ap2, d1)) goto fail; continue; } #ifdef RATIONAL_TREES /* now link the two structures so that no one else will */ /* come here */ to_visit -= 5; to_visit[0] = pt0; to_visit[1] = pt0_end; to_visit[2] = pt1; to_visit[3] = (CELL *)*pt0; to_visit[4] = (CELL *)write_mode; *pt0 = d1; #else /* store the terms to visit */ if (pt0 < pt0_end) { to_visit -= 4; to_visit[0] = pt0; to_visit[1] = pt0_end; to_visit[2] = pt1; to_visit[3] = (CELL *)write_mode; } #endif write_mode = our_write_mode; d0 = ArityOfFunctor(f); pt0 = ap2; pt0_end = ap2 + d0; pt1 = ap3; continue; } } } } /* Do we still have compound terms to visit */ if (to_visit < (CELL **)ASP) { #ifdef RATIONAL_TREES pt0 = to_visit[0]; pt0_end = to_visit[1]; pt1 = to_visit[2]; *pt0 = (CELL)to_visit[3]; write_mode = (int)to_visit[4]; to_visit += 5; #else pt0 = to_visit[0]; pt0_end = to_visit[1]; pt1 = to_visit[2]; write_mode = (int)to_visit[3]; to_visit += 4; #endif goto loop; } H = HBREG; /* get rid of intermediate variables */ new_tr = TR; while (TR != OLDTR) { /* cell we bound */ CELL *pt1 = (CELL *) TrailTerm(--TR); /* cell we created */ CELL *npt1 = (CELL *)*pt1; /* shorten the chain */ if (IsVarTerm(*pt1) && IsUnboundVar(pt1)) { RESET_VARIABLE(pt1); } else { *pt1 = *npt1; } } TR = new_tr; HBREG = B->cp_h; return TRUE; fail: H = HBREG; #ifdef RATIONAL_TREES while (to_visit < (CELL **)ASP) { pt0 = to_visit[0]; pt0_end = to_visit[1]; pt1 = to_visit[2]; *pt0 = (CELL)to_visit[3]; to_visit += 5; } #endif /* untrail all bindings made by variant */ while (TR != (tr_fr_ptr)OLDTR) { CELL *pt1 = (CELL *) TrailTerm(--TR); RESET_VARIABLE(pt1); } HBREG = B->cp_h; return FALSE; } static Int p_subsumes(void) /* subsumes terms t1 and t2 */ { Term t1 = Deref(ARG1); Term t2 = Deref(ARG2); if (t1 == t2) return (TRUE); if (IsVarTerm(t1)) { Bind(VarOfTerm(t1), t2); return(TRUE); } else if (IsVarTerm(t2)) return(FALSE); if (IsAtomOrIntTerm(t1)) { return(t1 == t2); } if (IsPairTerm(t1)) { if (IsPairTerm(t2)) { return(subsumes_complex(RepPair(t1)-1, RepPair(t1)+1, RepPair(t2)-1)); } else return (FALSE); } else { Functor f1; if (!IsApplTerm(t2)) return(FALSE); f1 = FunctorOfTerm(t1); if (f1 != FunctorOfTerm(t2)) return(FALSE); if (IsExtensionFunctor(f1)) { return(unify_extension(f1, t1, RepAppl(t1), t2)); } return(subsumes_complex(RepAppl(t1), RepAppl(t1)+ArityOfFunctor(f1), RepAppl(t2))); } } #ifdef DEBUG static Int p_force_trail_expansion() { Int i = IntOfTerm(Deref(ARG1))*1024, j = 0; tr_fr_ptr OTR = TR; for (j = 0; j < i; j++) { TrailTerm(TR) = 0; TR++; } TR = OTR; return(TRUE); } static Int camacho_dum(void) { Term t1, t2; int max = 3; /* build output list */ t1 = MkAtomTerm(Yap_LookupAtom("[]")); t2 = MkPairTerm(MkIntegerTerm(max), t1); return(Yap_unify(t2, ARG1)); } #endif /* DEBUG */ void Yap_InitUtilCPreds(void) { Term cm = CurrentModule; Yap_InitCPred("copy_term", 2, p_copy_term, 0); Yap_InitCPred("$copy_term_but_not_constraints", 2, p_copy_term_no_delays, HiddenPredFlag); Yap_InitCPred("ground", 1, p_ground, SafePredFlag); Yap_InitCPred("$variables_in_term", 3, p_variables_in_term, SafePredFlag|HiddenPredFlag); Yap_InitCPred("$non_singletons_in_term", 3, p_non_singletons_in_term, SafePredFlag|HiddenPredFlag); CurrentModule = TERMS_MODULE; Yap_InitCPred("term_variables", 2, p_term_variables, SafePredFlag); Yap_InitCPred("variable_in_term", 2, p_var_in_term, SafePredFlag); Yap_InitCPred("term_hash", 4, GvNTermHash, SafePredFlag); Yap_InitCPred("variant", 2, p_variant, 0); Yap_InitCPred("subsumes", 2, p_subsumes, SafePredFlag); CurrentModule = cm; #ifdef DEBUG Yap_InitCPred("$force_trail_expansion", 1, p_force_trail_expansion, SafePredFlag|HiddenPredFlag); Yap_InitCPred("dum", 1, camacho_dum, SafePredFlag); #endif }