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yap-6.3/C/terms.c
Vítor Santos Costa 38610c0b0d rational trees
2019-02-02 22:33:18 +00:00

1439 lines
41 KiB
C

/*************************************************************************
* *
* 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 *
* *
*************************************************************************/
/**
* @file C/terms.c
*
* @brief applications of the tree walker pattern.
*
* @addtogroup Terms
*
* @{
*
*/
#include "absmi.h"
#include "YapHeap.h"
#include "attvar.h"
#include "yapio.h"
#ifdef HAVE_STRING_H
#include "string.h"
#endif
static int expand_vts(int args USES_REGS) {
UInt expand = LOCAL_Error_Size;
yap_error_number yap_errno = LOCAL_Error_TYPE;
LOCAL_Error_Size = 0;
LOCAL_Error_TYPE = YAP_NO_ERROR;
if (yap_errno == RESOURCE_ERROR_TRAIL) {
/* Trail overflow */
if (!Yap_growtrail(expand, false)) {
return false;
}
} else if (yap_errno == RESOURCE_ERROR_AUXILIARY_STACK) {
/* Aux space overflow */
if (expand > 4 * 1024 * 1024)
expand = 4 * 1024 * 1024;
if (!Yap_ExpandPreAllocCodeSpace(expand, NULL, true)) {
return false;
}
} else {
if (!Yap_gcl(expand, 3, ENV, gc_P(P, CP))) {
Yap_Error(RESOURCE_ERROR_STACK, TermNil, "in term_variables");
return false;
}
}
return true;
}
static inline void clean_tr(tr_fr_ptr TR0 USES_REGS) {
if (TR != TR0) {
do {
Term p = TrailTerm(--TR);
RESET_VARIABLE(p);
} while (TR != TR0);
}
}
static inline void clean_dirty_tr(tr_fr_ptr TR0 USES_REGS) {
tr_fr_ptr pt0 = TR;
while (pt0 != TR0) {
Term p = TrailTerm(--pt0);
if (IsApplTerm(p)) {
CELL *pt = RepAppl(p);
#ifdef FROZEN_STACKS
pt[0] = TrailVal(pt0);
#else
pt[0] = TrailTerm(pt0 - 1);
pt0--;
#endif /* FROZEN_STACKS */
} else {
RESET_VARIABLE(p);
}
}
TR = TR0;
}
/// @brief recover original term while fixing direct refs.
///
/// @param USES_REGS
///
static inline void clean_complex_tr(tr_fr_ptr TR0 USES_REGS) {
tr_fr_ptr pt0 = TR;
while (pt0 != TR0) {
Term p = TrailTerm(--pt0);
if (IsApplTerm(p)) {
/// pt: points to the address of the new term we may want to fix.
CELL *pt = RepAppl(p);
if (pt >= HB && pt < HR) { /// is it new?
Term v = pt[0];
if (IsApplTerm(v)) {
/// yes, more than a single ref
*pt = (CELL)RepAppl(v);
}
#ifndef FROZEN_STACKS
pt0--;
#endif /* FROZEN_STACKS */
continue;
}
#ifdef FROZEN_STACKS
pt[0] = TrailVal(pt0);
#else
pt[0] = TrailTerm(pt0 - 1);
pt0--;
#endif /* FROZEN_STACKS */
} else {
RESET_VARIABLE(p);
}
}
TR = TR0;
}
typedef struct {
Term old_var;
Term new_var;
} * vcell;
typedef struct non_single_struct_t {
CELL *ptd0;
CELL d0;
CELL *pt0, *pt0_end;
} non_singletons_t;
#define WALK_COMPLEX_TERM__(LIST0, STRUCT0, PRIMI0) \
int lvl = push_text_stack(); \
\
struct non_single_struct_t *to_visit = Malloc( \
1024 * sizeof(struct non_single_struct_t)), \
*to_visit0 = to_visit, \
*to_visit_max = to_visit + 1024; \
\
restart: \
while (pt0 < pt0_end) { \
register CELL d0; \
register CELL *ptd0; \
++pt0; \
ptd0 = pt0; \
d0 = *ptd0; \
list_loop: \
deref_head(d0, var_in_term_unk); \
var_in_term_nvar : { \
if (IsPairTerm(d0)) { \
if (to_visit + 32 >= to_visit_max) { \
goto aux_overflow; \
} \
LIST0; \
ptd0 = RepPair(d0); \
if (*ptd0 == TermFreeTerm) \
goto restart; \
to_visit->pt0 = pt0; \
to_visit->pt0_end = pt0_end; \
to_visit->ptd0 = ptd0; \
to_visit->d0 = *ptd0; \
to_visit++; \
d0 = ptd0[0]; \
pt0 = ptd0; \
*ptd0 = TermFreeTerm; \
pt0_end = pt0 + 1; \
if (pt0 <= pt0_end) \
goto list_loop; \
} else if (IsApplTerm(d0)) { \
register Functor f; \
register CELL *ap2; \
/* store the terms to visit */ \
ap2 = RepAppl(d0); \
f = (Functor)(*ap2); \
\
if (IsExtensionFunctor(f) || IsAtomTerm((CELL)f)) { \
\
goto restart; \
} \
STRUCT0; \
if (to_visit + 32 >= to_visit_max) { \
goto aux_overflow; \
} \
to_visit->pt0 = pt0; \
to_visit->pt0_end = pt0_end; \
to_visit->ptd0 = ap2; \
to_visit->d0 = (CELL)f; \
to_visit++; \
\
*ap2 = TermNil; \
d0 = ArityOfFunctor(f); \
pt0 = ap2; \
pt0_end = ap2 + d0; \
goto restart;\
} else { \
PRIMI0; \
goto restart; } \
} \
derefa_body(d0, ptd0, var_in_term_unk, var_in_term_nvar);
#define WALK_COMPLEX_TERM() WALK_COMPLEX_TERM__({}, {}, {})
#define END_WALK() \
}
#define def_aux_overflow() \
aux_overflow : { \
size_t d1 = to_visit - to_visit0; \
size_t d2 = to_visit_max - to_visit0; \
to_visit0 = \
Realloc(to_visit0, (d2 + 128) * sizeof(struct non_single_struct_t)); \
to_visit = to_visit0 + d1; \
to_visit_max = to_visit0 + (d2 + 128); \
pt0--; \
} \
goto restart;
#define def_trail_overflow() \
trail_overflow : { \
while (to_visit > to_visit0) { \
to_visit--; \
CELL *ptd0 = to_visit->ptd0; \
*ptd0 = to_visit->d0; \
} \
pop_text_stack(lvl); \
LOCAL_Error_TYPE = RESOURCE_ERROR_TRAIL; \
LOCAL_Error_Size = (TR - TR0) * sizeof(tr_fr_ptr *); \
clean_tr(TR0 PASS_REGS); \
HR = InitialH; \
return 0L; \
}
#define def_global_overflow() \
global_overflow : { \
while (to_visit > to_visit0) { \
to_visit--; \
CELL *ptd0 = to_visit->ptd0; \
*ptd0 = to_visit->d0; \
} \
pop_text_stack(lvl); \
clean_tr(TR0 PASS_REGS); \
HR = InitialH; \
LOCAL_Error_TYPE = RESOURCE_ERROR_STACK; \
LOCAL_Error_Size = (ASP - HR) * sizeof(CELL); \
return false; \
}
static Int var_in_complex_term(register CELL *pt0, register CELL *pt0_end,
Term v USES_REGS) {
WALK_COMPLEX_TERM();
if ((CELL)d0 == v) { /* we found it */
/* Do we still have compound terms to visit */
while (to_visit > to_visit0) {
to_visit--;
CELL *ptd0 = to_visit->ptd0;
*ptd0 = to_visit->d0;
}
pop_text_stack(lvl);
return true;
}
END_WALK();
if (to_visit > to_visit0) {
to_visit--;
CELL *ptd0 = to_visit->ptd0;
*ptd0 = to_visit->d0;
pt0 = to_visit->pt0;
pt0_end = to_visit->pt0_end;
}
pop_text_stack(lvl);
return false;
def_aux_overflow();
}
static Int var_in_term(Term v,
Term t USES_REGS) /* variables in term t */
{
must_be_variable(v);
t = Deref(t);
if (IsVarTerm(t)) {
return (v == t);
} else if (IsPrimitiveTerm(t)) {
return (false);
}
return (var_in_complex_term(&(t)-1, &(t), v PASS_REGS));
}
/** @pred variable_in_term(? _Term_,? _Var_)
Succeed if the second argument _Var_ is a variable and occurs in
term _Term_.
*/
static Int variable_in_term(USES_REGS1) {
return var_in_term(Deref(ARG2), Deref(ARG1) PASS_REGS);
}
/**
@brief routine to locate all variables in a term, and its applications */
static Term vars_in_complex_term(register CELL *pt0, register CELL *pt0_end,
Term inp USES_REGS) {
register tr_fr_ptr TR0 = TR;
CELL *InitialH = HR;
CELL output = AbsPair(HR);
WALK_COMPLEX_TERM();
/* do or pt2 are unbound */
*ptd0 = TermNil;
/* leave an empty slot to fill in later */
if (HR + 1024 > ASP) {
goto global_overflow;
}
HR[1] = AbsPair(HR + 2);
HR += 2;
HR[-2] = (CELL)ptd0;
/* next make sure noone will see this as a variable again */
if (TR > (tr_fr_ptr)LOCAL_TrailTop - 256) {
/* Trail overflow */
if (!Yap_growtrail((TR - TR0) * sizeof(tr_fr_ptr *), true)) {
goto trail_overflow;
}
}
TrailTerm(TR++) = (CELL)ptd0;
END_WALK();
/* Do we still have compound terms to visit */
if (to_visit > to_visit0) {
to_visit--;
pt0 = to_visit->pt0;
pt0_end = to_visit->pt0_end;
CELL *ptd0 = to_visit->ptd0;
*ptd0 = to_visit->d0;
goto restart;
}
clean_tr(TR0 PASS_REGS);
pop_text_stack(lvl);
if (HR != InitialH) {
/* close the list */
Term t2 = Deref(inp);
if (IsVarTerm(t2)) {
RESET_VARIABLE(HR - 1);
Yap_unify((CELL)(HR - 1), inp);
} else {
HR[-1] = t2; /* don't need to trail */
}
return (output);
} else {
return (inp);
}
def_trail_overflow();
def_aux_overflow();
def_global_overflow();
}
static Int
p_variables_in_term(USES_REGS1) /* variables in term t */
{
Term out, inp;
int count;
restart:
count = 0;
inp = Deref(ARG2);
while (!IsVarTerm(inp) && IsPairTerm(inp)) {
Term t = HeadOfTerm(inp);
if (IsVarTerm(t)) {
CELL *ptr = VarOfTerm(t);
*ptr = TermFoundVar;
TrailTerm(TR++) = t;
count++;
if (TR > (tr_fr_ptr)LOCAL_TrailTop - 256) {
clean_tr(TR - count PASS_REGS);
if (!Yap_growtrail(count * sizeof(tr_fr_ptr *), false)) {
return false;
}
goto restart;
}
}
inp = TailOfTerm(inp);
}
do {
Term t = Deref(ARG1);
out = vars_in_complex_term(&(t)-1, &(t), ARG2 PASS_REGS);
if (out == 0L) {
if (!expand_vts(3 PASS_REGS))
return false;
}
} while (out == 0L);
clean_tr(TR - count PASS_REGS);
return Yap_unify(ARG3, out);
}
/** @pred term_variables(? _Term_, - _Variables_, +_ExternalVars_) is iso
Unify the difference list between _Variables_ and _ExternaVars_
with the list of all variables of term _Term_. The variables
occur in the order of their first appearance when traversing the
term depth-first, left-to-right.
*/
static Int p_term_variables3(USES_REGS1) /* variables in term t */
{
Term out;
do {
Term t = Deref(ARG1);
if (IsVarTerm(t)) {
Term out = Yap_MkNewPairTerm();
return Yap_unify(t, HeadOfTerm(out)) &&
Yap_unify(ARG3, TailOfTerm(out)) && Yap_unify(out, ARG2);
} else if (IsPrimitiveTerm(t)) {
return Yap_unify(ARG2, ARG3);
} else {
out = vars_in_complex_term(&(t)-1, &(t), ARG3 PASS_REGS);
}
if (out == 0L) {
if (!expand_vts(3 PASS_REGS))
return false;
}
} while (out == 0L);
return Yap_unify(ARG2, out);
}
/**
* Exports a nil-terminated list with all the variables in a term.
* @param[t] the term
* @param[arity] the arity of the calling predicate (required for exact garbage
* collection).
* @param[USES_REGS] threading
*/
Term Yap_TermVariables(
Term t, UInt arity USES_REGS) /* variables in term t */
{
Term out;
do {
t = Deref(t);
if (IsVarTerm(t)) {
return MkPairTerm(t, TermNil);
} else if (IsPrimitiveTerm(t)) {
return TermNil;
} else {
out = vars_in_complex_term(&(t)-1, &(t), TermNil PASS_REGS);
}
if (out == 0L) {
if (!expand_vts(arity PASS_REGS))
return false;
}
} while (out == 0L);
return out;
}
/** @pred term_variables(? _Term_, - _Variables_) is iso
Unify _Variables_ with the list of all variables of term
_Term_. The variables occur in the order of their first
appearance when traversing the term depth-first, left-to-right.
*/
static Int p_term_variables(USES_REGS1) /* variables in term t */
{
Term out;
if (!Yap_IsListOrPartialListTerm(ARG2)) {
Yap_Error(TYPE_ERROR_LIST, ARG2, "term_variables/2");
return false;
}
do {
Term t = Deref(ARG1);
out = vars_in_complex_term(&(t)-1, &(t), TermNil PASS_REGS);
if (out == 0L) {
if (!expand_vts(3 PASS_REGS))
return false;
}
} while (out == 0L);
return Yap_unify(ARG2, out);
}
/** routine to locate attributed variables */
typedef struct att_rec {
CELL *beg, *end;
CELL oval;
} att_rec_t;
static Term attvars_in_complex_term(register CELL *pt0, register CELL *pt0_end,
Term inp USES_REGS) {
register tr_fr_ptr TR0 = TR;
CELL *InitialH = HR;
CELL output = AbsPair(HR);
WALK_COMPLEX_TERM();
if (IsAttVar(ptd0)) {
/* do or pt2 are unbound */
attvar_record *a0 = RepAttVar(ptd0);
if (a0->AttFunc == (Functor)TermNil)
goto restart;
/* leave an empty slot to fill in later */
if (HR + 1024 > ASP) {
goto global_overflow;
}
HR[1] = AbsPair(HR + 2);
HR += 2;
HR[-2] = (CELL) & (a0->Done);
/* store the terms to visit */
if (to_visit + 32 >= to_visit_max) {
goto aux_overflow;
}
ptd0 = (CELL *)a0;
to_visit->pt0 = pt0;
to_visit->pt0_end = pt0_end;
to_visit->d0 = *ptd0;
to_visit->ptd0 = ptd0;
to_visit++;
*ptd0 = TermNil;
pt0_end = &RepAttVar(ptd0)->Atts;
pt0 = pt0_end - 1;
}
END_WALK();
/* Do we still have compound terms to visit */
if (to_visit > to_visit0) {
to_visit--;
pt0 = to_visit->pt0;
pt0_end = to_visit->pt0_end;
CELL *ptd0 = to_visit->ptd0;
*ptd0 = to_visit->d0;
goto restart;
}
clean_tr(TR0 PASS_REGS);
pop_text_stack(lvl);
if (HR != InitialH) {
/* close the list */
Term t2 = Deref(inp);
if (IsVarTerm(t2)) {
RESET_VARIABLE(HR - 1);
Yap_unify((CELL)(HR - 1), t2);
} else {
HR[-1] = t2; /* don't need to trail */
}
return (output);
} else {
return (inp);
}
def_aux_overflow();
def_global_overflow();
}
/** @pred term_attvars(+ _Term_,- _AttVars_)
_AttVars_ is a list of all attributed variables in _Term_ and
its attributes. I.e., term_attvars/2 works recursively through
attributes. This predicate is Cycle-safe.
*/
static Int p_term_attvars(USES_REGS1) /* variables in term t */
{
Term out;
do {
Term t = Deref(ARG1);
if (IsPrimitiveTerm(t)) {
return Yap_unify(TermNil, ARG2);
} else {
out = attvars_in_complex_term(&(t)-1, &(t), TermNil PASS_REGS);
}
if (out == 0L) {
if (!expand_vts(3 PASS_REGS))
return false;
}
} while (out == 0L);
return Yap_unify(ARG2, out);
}
/** @brief output the difference between variables in _T_ and variables in some
* list.
*/
static Term new_vars_in_complex_term(register CELL *pt0, register CELL *pt0_end,
Term inp USES_REGS) {
register tr_fr_ptr TR0 = TR;
CELL *InitialH = HR;
CELL output = AbsPair(HR);
while (!IsVarTerm(inp) && IsPairTerm(inp)) {
Term t = HeadOfTerm(inp);
if (IsVarTerm(t)) {
CELL *ptr = VarOfTerm(t);
*ptr = TermFoundVar;
TrailTerm(TR++) = t;
if (TR > (tr_fr_ptr)LOCAL_TrailTop - 256) {
if (!Yap_growtrail((TR - TR0) * sizeof(tr_fr_ptr *), true)) {
goto trail_overflow;
}
}
}
inp = TailOfTerm(inp);
}
WALK_COMPLEX_TERM();
/* do or pt2 are unbound */
*ptd0 = TermNil;
/* leave an empty slot to fill in later */
if (HR + 1024 > ASP) {
goto global_overflow;
}
HR[1] = AbsPair(HR + 2);
HR += 2;
HR[-2] = (CELL)ptd0;
/* next make sure noone will see this as a variable again */
if (TR > (tr_fr_ptr)LOCAL_TrailTop - 256) {
/* Trail overflow */
if (!Yap_growtrail((TR - TR0) * sizeof(tr_fr_ptr *), true)) {
goto trail_overflow;
}
}
TrailTerm(TR++) = (CELL)ptd0;
END_WALK();
/* Do we still have compound terms to visit */
if (to_visit > to_visit0) {
to_visit--;
pt0 = to_visit->pt0;
pt0_end = to_visit->pt0_end;
CELL *ptd0 = to_visit->ptd0;
*ptd0 = to_visit->d0;
goto restart;
}
clean_tr(TR0 PASS_REGS);
pop_text_stack(lvl);
if (HR != InitialH) {
HR[-1] = TermNil;
return output;
} else {
return TermNil;
}
def_aux_overflow();
def_trail_overflow();
def_global_overflow();
}
/** @pred new_variables_in_term(+_CurrentVariables_, ? _Term_, -_Variables_)
Unify _Variables_ with the list of all variables of term
_Term_ that do not occur in _CurrentVariables_. The variables occur in the
order of their first appearance when traversing the term depth-first,
left-to-right.
*/
static Int
p_new_variables_in_term(USES_REGS1) /* variables within term t */
{
Term out;
do {
Term t = Deref(ARG2);
if (IsPrimitiveTerm(t))
out = TermNil;
else {
out = new_vars_in_complex_term(&(t)-1, &(t), Deref(ARG1) PASS_REGS);
}
if (out == 0L) {
if (!expand_vts(3 PASS_REGS))
return false;
}
} while (out == 0L);
return Yap_unify(ARG3, out);
}
#define FOUND_VAR() \
if (d0 == TermFoundVar) { \
/* leave an empty slot to fill in later */ \
if (HR + 1024 > ASP) { \
goto global_overflow; \
} \
HR[1] = AbsPair(HR + 2); \
HR += 2; \
HR[-2] = (CELL)ptd0; \
*ptd0 = TermNil; \
}
static Term vars_within_complex_term(register CELL *pt0, register CELL *pt0_end,
Term inp USES_REGS) {
tr_fr_ptr TR0 = TR;
CELL *InitialH = HR;
CELL output = AbsPair(HR);
while (!IsVarTerm(inp) && IsPairTerm(inp)) {
Term t = HeadOfTerm(inp);
if (IsVarTerm(t)) {
CELL *ptr = VarOfTerm(t);
*ptr = TermFoundVar;
TrailTerm(TR++) = t;
if (TR > (tr_fr_ptr)LOCAL_TrailTop - 256) {
Yap_growtrail((TR - TR0) * sizeof(tr_fr_ptr *), true);
}
}
inp = TailOfTerm(inp);
}
WALK_COMPLEX_TERM__({}, {}, FOUND_VAR());
END_WALK();
/* Do we still have compound terms to visit */
if (to_visit > to_visit0) {
to_visit--;
pt0 = to_visit->pt0;
pt0_end = to_visit->pt0_end;
CELL *ptd0 = to_visit->ptd0;
*ptd0 = to_visit->d0;
goto restart;
}
clean_tr(TR0 PASS_REGS);
pop_text_stack(lvl);
if (HR != InitialH) {
HR[-1] = TermNil;
return output;
} else {
return TermNil;
}
def_aux_overflow();
def_global_overflow();
}
/** @pred variables_within_term(+_CurrentVariables_, ? _Term_, -_Variables_)
Unify _Variables_ with the list of all variables of term _Term_
that *also* occur in _CurrentVariables_. The variables occur in
the order of their first appearance when traversing the term
depth-first, left-to-right.
This predicate performs the opposite of new_variables_in_term/3.
*/
static Int p_variables_within_term(USES_REGS1) /* variables within term t */
{
Term out;
do {
Term t = Deref(ARG2);
if (IsPrimitiveTerm(t))
out = TermNil;
else {
out = vars_within_complex_term(&(t)-1, &(t), Deref(ARG1) PASS_REGS);
}
if (out == 0L) {
if (!expand_vts(3 PASS_REGS))
return false;
}
} while (out == 0L);
return Yap_unify(ARG3, out);
}
static Term free_vars_in_complex_term(CELL *pt0, CELL *pt0_end,
tr_fr_ptr TR0 USES_REGS) {
Term o = TermNil;
CELL *InitialH = HR;
WALK_COMPLEX_TERM();
/* do or pt2 are unbound */
*ptd0 = TermNil;
/* leave an empty slot to fill in later */
if (HR + 1024 > ASP) {
o = TermNil;
goto global_overflow;
}
HR[0] = (CELL)ptd0;
HR[1] = o;
o = AbsPair(HR);
HR += 2;
/* next make sure noone will see this as a variable again */
if (TR > (tr_fr_ptr)LOCAL_TrailTop - 256) {
/* Trail overflow */
if (!Yap_growtrail((TR - TR0) * sizeof(tr_fr_ptr *), true)) {
goto trail_overflow;
}
}
TrailTerm(TR++) = (CELL)ptd0;
END_WALK();
/* Do we still have compound terms to visit */
if (to_visit > to_visit0) {
to_visit--;
pt0 = to_visit->pt0;
pt0_end = to_visit->pt0_end;
CELL *ptd0 = to_visit->ptd0;
*ptd0 = to_visit->d0;
goto restart;
}
clean_tr(TR0 PASS_REGS);
pop_text_stack(lvl);
return o;
def_aux_overflow();
def_trail_overflow();
def_global_overflow();
}
static Term bind_vars_in_complex_term(CELL *pt0, CELL *pt0_end,
tr_fr_ptr TR0 USES_REGS) {
CELL *InitialH = HR;
WALK_COMPLEX_TERM();
/* do or pt2 are unbound */
*ptd0 = TermFoundVar;
/* next make sure noone will see this as a variable again */
if (TR > (tr_fr_ptr)LOCAL_TrailTop - 256) {
/* Trail overflow */
if (!Yap_growtrail((TR - TR0) * sizeof(tr_fr_ptr *), true)) {
goto trail_overflow;
}
}
TrailTerm(TR++) = (CELL)ptd0;
END_WALK();
/* Do we still have compound terms to visit */
if (to_visit > to_visit0) {
to_visit--;
pt0 = to_visit->ptd0;
*pt0 = to_visit0->d0;
goto list_loop;
}
pop_text_stack(lvl);
return TermNil;
def_aux_overflow();
def_trail_overflow();
}
static Int
p_free_variables_in_term(USES_REGS1) /* variables within term t */
{
Term out;
Term t, t0;
Term found_module = 0L;
do {
tr_fr_ptr TR0 = TR;
t = t0 = Deref(ARG1);
while (!IsVarTerm(t) && IsApplTerm(t)) {
Functor f = FunctorOfTerm(t);
if (f == FunctorHat) {
out = bind_vars_in_complex_term(RepAppl(t), RepAppl(t) + 1,
TR0 PASS_REGS);
if (out == 0L) {
goto trail_overflow;
}
} else if (f == FunctorModule) {
found_module = ArgOfTerm(1, t);
} else if (f == FunctorCall) {
t = ArgOfTerm(1, t);
} else if (f == FunctorExecuteInMod) {
found_module = ArgOfTerm(2, t);
t = ArgOfTerm(1, t);
} else {
break;
}
t = ArgOfTerm(2, t);
}
if (IsPrimitiveTerm(t))
out = TermNil;
else {
out = free_vars_in_complex_term(&(t)-1, &(t), TR0 PASS_REGS);
}
if (out == 0L) {
trail_overflow:
if (!expand_vts(3 PASS_REGS))
return false;
}
} while (out == 0L);
if (found_module && t != t0) {
Term ts[2];
ts[0] = found_module;
ts[1] = t;
t = Yap_MkApplTerm(FunctorModule, 2, ts);
}
return Yap_unify(ARG2, t) && Yap_unify(ARG3, out);
}
#define FOUND_VAR_AGAIN() \
if (d0 == TermFoundVar) { \
CELL *pt2 = pt0; \
while (IsVarTerm(*pt2)) \
pt2 = (CELL *)(*pt2); \
HR[1] = AbsPair(HR + 2); \
HR[0] = (CELL)pt2; \
HR += 2; \
*pt2 = TermRefoundVar; \
}
static Term non_singletons_in_complex_term(CELL *pt0, CELL *pt0_end USES_REGS) {
tr_fr_ptr TR0 = TR;
CELL *InitialH = HR;
CELL output = AbsPair(HR);
WALK_COMPLEX_TERM__({}, {}, FOUND_VAR_AGAIN());
/* do or pt2 are unbound */
*ptd0 = TermFoundVar;
/* next make sure we can recover the variable again */
TrailTerm(TR++) = (CELL)ptd0;
END_WALK();
/* Do we still have compound terms to visit */
if (to_visit > to_visit0) {
to_visit--;
pt0 = to_visit->pt0;
pt0_end = to_visit->pt0_end;
CELL *ptd0 = to_visit->ptd0;
*ptd0 = to_visit->d0;
goto restart;
}
clean_tr(TR0 PASS_REGS);
pop_text_stack(lvl);
if (HR != InitialH) {
/* close the list */
HR[-1] = Deref(ARG2);
return output;
} else {
return ARG2;
}
def_aux_overflow();
}
static Int p_non_singletons_in_term(
USES_REGS1) /* non_singletons in term t */
{
Term t;
Term out;
while (true) {
t = Deref(ARG1);
if (IsVarTerm(t)) {
out = ARG2;
} else if (IsPrimitiveTerm(t)) {
out = ARG2;
} else {
out = non_singletons_in_complex_term(&(t)-1, &(t)PASS_REGS);
}
if (out != 0L) {
return Yap_unify(ARG3, out);
}
}
}
static Int ground_complex_term(CELL *pt0, CELL *pt0_end USES_REGS) {
WALK_COMPLEX_TERM();
/* found a variable */
while (to_visit > to_visit0) {
to_visit--;
CELL *ptd0 = to_visit->ptd0;
*ptd0 = to_visit->d0;
}
pop_text_stack(lvl);
return false;
END_WALK();
/* Do we still have compound terms to visit */
if (to_visit > to_visit0) {
to_visit--;
pt0 = to_visit->pt0;
pt0_end = to_visit->pt0_end;
CELL *ptd0 = to_visit->ptd0;
*ptd0 = to_visit->d0;
goto restart;
}
pop_text_stack(lvl);
return true;
def_aux_overflow();
}
bool Yap_IsGroundTerm(Term t) {
CACHE_REGS
while (true) {
Int out;
if (IsVarTerm(t)) {
return false;
} else if (IsPrimitiveTerm(t)) {
return true;
} else {
if ((out = ground_complex_term(&(t)-1, &(t)PASS_REGS)) >= 0) {
return out != 0;
}
if (out < 0) {
*HR++ = t;
t = *--HR;
}
}
}
}
/** @pred ground( _T_) is iso
Succeeds if there are no free variables in the term _T_.
*/
static Int p_ground(USES_REGS1) /* ground(+T) */
{
return Yap_IsGroundTerm(Deref(ARG1));
}
static Term numbervar(Int id USES_REGS) {
Term ts[1];
ts[0] = MkIntegerTerm(id);
return Yap_MkApplTerm(FunctorDollarVar, 1, ts);
}
static Term numbervar_singleton(USES_REGS1) {
Term ts[1];
ts[0] = MkIntegerTerm(-1);
return Yap_MkApplTerm(FunctorDollarVar, 1, ts);
}
static void renumbervar(Term t, Int id USES_REGS) {
Term *ts = RepAppl(t);
ts[1] = MkIntegerTerm(id);
}
#define RENUMBER_SINGLES \
if (singles && ap2 >= InitialH && ap2 < HR) { \
renumbervar(d0, numbv++ PASS_REGS); \
goto restart; \
}
static Int numbervars_in_complex_term(CELL *pt0, CELL *pt0_end, Int numbv,
int singles USES_REGS) {
tr_fr_ptr TR0 = TR;
CELL *InitialH = HR;
WALK_COMPLEX_TERM__({}, RENUMBER_SINGLES, {});
/* do or pt2 are unbound */
if (singles)
*ptd0 = numbervar_singleton(PASS_REGS1);
else
*ptd0 = numbervar(numbv++ PASS_REGS);
/* leave an empty slot to fill in later */
if (HR + 1024 > ASP) {
goto global_overflow;
}
/* next make sure noone will see this as a variable again */
if (TR > (tr_fr_ptr)LOCAL_TrailTop - 256) {
/* Trail overflow */
if (!Yap_growtrail((TR - TR0) * sizeof(tr_fr_ptr *), true)) {
goto trail_overflow;
}
}
#if defined(TABLING) || defined(YAPOR_SBA)
TrailVal(TR) = (CELL)ptd0;
#endif
TrailTerm(TR++) = (CELL)ptd0;
END_WALK();
/* Do we still have compound terms to visit */
if (to_visit > to_visit0) {
to_visit--;
pt0 = to_visit->pt0;
pt0_end = to_visit->pt0_end;
CELL *ptd0 = to_visit->ptd0;
*ptd0 = to_visit->d0;
goto restart;
}
prune(B PASS_REGS);
pop_text_stack(lvl);
return numbv;
def_aux_overflow();
def_global_overflow();
def_trail_overflow();
}
Int Yap_NumberVars(Term inp, Int numbv,
bool handle_singles) /*
* numbervariables in term t */
{
CACHE_REGS
Int out;
Term t;
restart:
t = Deref(inp);
if (IsPrimitiveTerm(t)) {
return numbv;
} else {
out = numbervars_in_complex_term(&(t)-1, &(t), numbv,
handle_singles PASS_REGS);
}
if (out < numbv) {
if (!expand_vts(3 PASS_REGS))
return false;
goto restart;
}
return out;
}
/** @pred numbervars( _T_,+ _N1_,- _Nn_)
Instantiates each variable in term _T_ to a term of the form:
`$VAR( _I_)`, with _I_ increasing from _N1_ to _Nn_.
*/
static Int p_numbervars(USES_REGS1) {
Term t2 = Deref(ARG2);
Int out;
if (IsVarTerm(t2)) {
Yap_Error(INSTANTIATION_ERROR, t2, "numbervars/3");
return false;
}
if (!IsIntegerTerm(t2)) {
Yap_Error(TYPE_ERROR_INTEGER, t2, "numbervars/3");
return (false);
}
if ((out = Yap_NumberVars(ARG1, IntegerOfTerm(t2), false)) < 0)
return false;
return Yap_unify(ARG3, MkIntegerTerm(out));
}
#define MAX_NUMBERED \
if (FunctorOfTerm(d0) == FunctorDollarVar) { \
Term t1 = ArgOfTerm(1, d0); \
Int i; \
if (IsIntegerTerm(t1) && ((i = IntegerOfTerm(t1)) > *maxp)) \
*maxp = i; \
goto restart; \
}
static int max_numbered_var(CELL *pt0, CELL *pt0_end, Int *maxp USES_REGS) {
WALK_COMPLEX_TERM__({}, MAX_NUMBERED, {});
END_WALK();
/* Do we still have compound terms to visit */
if (to_visit > to_visit0) {
to_visit--;
pt0 = to_visit->pt0;
pt0_end = to_visit->pt0_end;
CELL *ptd0 = to_visit->ptd0;
*ptd0 = to_visit->d0;
}
prune(B PASS_REGS);
pop_text_stack(lvl);
return 0;
def_aux_overflow();
}
static Int MaxNumberedVar(Term inp, UInt arity PASS_REGS) {
Term t = Deref(inp);
if (IsPrimitiveTerm(t)) {
return MkIntegerTerm(0);
} else {
Int res;
Int max;
res = max_numbered_var(&t - 1, &t, &max PASS_REGS) - 1;
if (res < 0)
return -1;
return MkIntegerTerm(max);
}
}
/**
* @pred largest_numbervar( +_Term_, -Max)
*
* Unify _Max_ with the largest integer _I_ such that `$VAR(I)` is a
* sub-term of _Term_.
*
* This built-in predicate is useful if part of a term has been grounded, and
* now you want to ground the full term.
*/
static Int largest_numbervar(USES_REGS1)
{
return Yap_unify(MaxNumberedVar(Deref(ARG1), 2 PASS_REGS), ARG2);
}
static Term BREAK_LOOP(int ddep ) {
Term t0 = MkIntegerTerm (ddep);
return Yap_MkApplTerm(Yap_MkFunctor(Yap_LookupAtom("@^"), 1), 1, &t0);
}
static Term UNFOLD_LOOP( Term t, Term *b, Term *l) {
Term ti = Yap_MkNewApplTerm(FunctorEq, 2);
RepAppl(ti)[2] = t;
Term o = RepAppl(ti)[1];
HR[0] = ti;
HR[1] = *l;
l[0] = AbsPair(HR);
if (b!=NULL && *b==TermNil)
b = l;
l = HR+1;
HR+=2;
return o;
}
static int loops_in_complex_term(CELL *pt0, CELL *pt0_end, Term *listp, Term *endp USES_REGS) {
int lvl = push_text_stack();
struct non_single_struct_t *to_visit = Malloc(
1024 * sizeof(struct non_single_struct_t)),
*to_visit0 = to_visit,
*to_visit_max = to_visit + 1024;
to_visit0 = to_visit;
to_visit_max = to_visit0 + 1024;
restart:
while (pt0 < pt0_end) {
CELL d0;
CELL *ptd0;
++pt0;
ptd0 = pt0;
d0 = *ptd0;
list_loop:
deref_head(d0, vars_in_term_unk);
vars_in_term_nvar :
if (IsPairTerm(d0)) {
if (to_visit + 32 >= to_visit_max) {
goto aux_overflow;
}
CELL *headp = RepPair(d0);
d0 = headp[0];
if (IsAtomTerm(d0) &&
(CELL *)AtomOfTerm(d0) >= (CELL *)to_visit0 &&
(CELL *)AtomOfTerm(d0) < (CELL *)to_visit_max) {
// LIST0;
struct non_single_struct_t *v0 = (struct non_single_struct_t *)AtomOfTerm(d0);
if (listp) {
*ptd0 = UNFOLD_LOOP(AbsPair(headp), listp, endp);
} else {
*ptd0 = BREAK_LOOP(to_visit-v0);
}
goto restart;
}
to_visit->pt0 = pt0;
to_visit->pt0_end = pt0_end;
to_visit->ptd0 = headp;
to_visit->d0 = d0;
*headp = MkAtomTerm((AtomEntry*)to_visit);
to_visit++;
pt0 = headp;
pt0_end = pt0 + 1;
ptd0 = pt0;
goto list_loop;
} 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 (IsAtomTerm((CELL)f)) {
if (listp) {
*ptd0 = UNFOLD_LOOP(AbsAppl(ap2), listp, endp);
} else {
*ptd0 = BREAK_LOOP(to_visit-(struct non_single_struct_t *)AtomOfTerm(*ap2));
}
goto restart;
}
// STRUCT0;
if (to_visit + 32 >= to_visit_max) {
goto aux_overflow;
}
to_visit->pt0 = pt0;
to_visit->pt0_end = pt0_end;
to_visit->ptd0 = ap2;
to_visit->d0 = *ap2;
*ap2 = MkAtomTerm((AtomEntry*)to_visit);
to_visit++;
pt0 = ap2;
pt0_end = ap2 + (ArityOfFunctor(f));
}
goto restart;
derefa_body(d0, ptd0, vars_in_term_unk, vars_in_term_nvar);
goto restart;
}
/* Do we still have compound terms to visit */
if (to_visit > to_visit0) {
to_visit--;
pt0 = to_visit->pt0;
pt0_end = to_visit->pt0_end;
CELL *ptd0 = to_visit->ptd0;
if (!IsVarTerm(*ptd0))
*ptd0 = to_visit->d0;
goto restart;
}
pop_text_stack(lvl);
return 0;
def_aux_overflow();
}
Term Yap_CheckLoops(Term inp, UInt arity, Term *listp, Term *endp USES_REGS) {
Term t = Deref(inp);
if (IsVarTerm(t) || IsPrimitiveTerm(t)) {
return t;
} else {
Int res;
res = loops_in_complex_term((&t) - 1, &t, listp, endp PASS_REGS);
if (res < 0)
return -1;
return t;
}
}
/** @pred rational_term_to_tree(? _TI_,- _TF_, ?SubTerms, ?MoreSubterms)
The term _TF_ is a forest representation (without cycles) for
the Prolog term _TI_. The term _TF_ is the main term. The
difference list _SubTerms_-_MoreSubterms_ stores terms of the
form _V=T_, where _V_ is a new variable occuring in _TF_, and
_T_ is a copy of a sub-term from _TI_.
*/
static Int p_break_rational(USES_REGS1)
{
Term t = Yap_CopyTerm(Deref(ARG1));
Term l = Deref(ARG4), k;
return Yap_unify(Yap_CheckLoops(t, 4, &k, &l PASS_REGS), ARG2) && Yap_unify(k, ARG3);
}
void Yap_InitTermCPreds(void) {
Yap_InitCPred("rational_term_to_tree", 4, p_break_rational, 0);
Yap_InitCPred("term_variables", 2, p_term_variables, 0);
Yap_InitCPred("term_variables", 3, p_term_variables3, 0);
Yap_InitCPred("$variables_in_term", 3, p_variables_in_term, 0);
Yap_InitCPred("$free_variables_in_term", 3, p_free_variables_in_term, 0);
Yap_InitCPred("term_attvars", 2, p_term_attvars, 0);
CurrentModule = TERMS_MODULE;
Yap_InitCPred("variable_in_term", 2, variable_in_term, 0);
Yap_InitCPred("variables_within_term", 3, p_variables_within_term, 0);
Yap_InitCPred("new_variables_in_term", 3, p_new_variables_in_term, 0);
CurrentModule = PROLOG_MODULE;
Yap_InitCPred("$non_singletons_in_term", 3, p_non_singletons_in_term, 0);
Yap_InitCPred("ground", 1, p_ground, SafePredFlag);
Yap_InitCPred("numbervars", 3, p_numbervars, 0);
Yap_InitCPred("largest_numbervar", 2, largest_numbervar, 0);
}