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yap-6.3/C/terms.c

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2019-01-30 15:24:06 +00:00
/*************************************************************************
* *
* 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
/**
* @file C/terms.c
*
* @brief applications of the tree walker pattern.
*
* @addtogroup Terms
* @{
*/
#include "absmi.h"
#include "YapHeap.h"
#include "yapio.h"
#include "attvar.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) \
if (IsPairTerm(d0)) { \
if (to_visit + 32 >= to_visit_max) { \
goto aux_overflow; \
} \
LIST0; \
ptd0 = RepPair(d0); \
if (*ptd0 == TermFreeTerm) continue; \
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)) { \
\
continue; \
} \
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; \
to_visit ++; \
\
*ap2 = TermNil; \
d0 = ArityOfFunctor(f); \
pt0 = ap2; \
pt0_end = ap2 + d0; \
}
#define WALK_COMPLEX_TERM() WALK_COMPLEX_TERM__({}, {})
#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_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_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)
{
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;
while (pt0 < pt0_end) {
register CELL d0;
register CELL *ptd0;
restart:
++ pt0;
ptd0 = pt0;
d0 = *ptd0;
list_loop:
deref_head(d0, var_in_term_unk);
var_in_term_nvar:
{
WALK_COMPLEX_TERM();
continue;
}
deref_body(d0, ptd0, var_in_term_unk, var_in_term_nvar);
if ((CELL)ptd0 == 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;
}
}
pop_text_stack(lvl);
return false;
def_aux_overflow();
}
static Int
var_in_term(Term v, Term t USES_REGS) /* 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 PASS_REGS));
}
else return(var_in_complex_term(RepAppl(t),
RepAppl(t)+
ArityOfFunctor(FunctorOfTerm(t)),v PASS_REGS));
}
static Int
p_var_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)
{
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;
register tr_fr_ptr TR0 = TR;
CELL *InitialH = HR;
CELL output = AbsPair(HR);
loop:
while (pt0 < pt0_end) {
register CELL d0;
register CELL *ptd0;
restart:
++ pt0;
ptd0 = pt0;
d0 = *ptd0;
list_loop:
deref_head(d0, vars_in_term_unk);
vars_in_term_nvar:
WALK_COMPLEX_TERM();
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 */
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;
}
/* 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 loop;
}
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)
{
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;
register tr_fr_ptr TR0 = TR;
CELL *InitialH = HR;
CELL output = AbsPair(HR);
restart:
while (pt0 < pt0_end) {
register CELL d0;
register CELL *ptd0;
++ pt0;
ptd0 = pt0;
d0 = *ptd0;
list_loop:
deref_head(d0, attvars_in_term_unk);
attvars_in_term_nvar:
{
WALK_COMPLEX_TERM();
continue;
}
derefa_body(d0, ptd0, attvars_in_term_unk, attvars_in_term_nvar);
if (IsAttVar(ptd0)) {
/* do or pt2 are unbound */
attvar_record *a0 = RepAttVar(ptd0);
if (a0->AttFunc ==(Functor) TermNil) continue;
/* 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;
}
}
/* 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)
{
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;
register tr_fr_ptr TR0 = TR;
CELL *InitialH = HR;
CELL output = AbsPair(HR);
to_visit0 = to_visit;
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);
}
restart:
while (pt0 < pt0_end) {
register CELL d0;
register CELL *ptd0;
++ pt0;
ptd0 = pt0;
d0 = *ptd0;
list_loop:
deref_head(d0, vars_within_term_unk);
vars_within_term_nvar:
{
WALK_COMPLEX_TERM();
continue;
}
derefa_body(d0, ptd0, vars_within_term_unk, vars_within_term_nvar);
/* 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;
}
/* 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_trail_overflow();
def_aux_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);
}
static Term vars_within_complex_term(register CELL *pt0, register CELL *pt0_end, Term inp 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;
register tr_fr_ptr TR0 = TR;
CELL *InitialH = HR;
CELL output = AbsPair(HR);
to_visit0 = to_visit;
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);
}
restart:
while (pt0 < pt0_end) {
register CELL d0;
register CELL *ptd0;
++ pt0;
ptd0 = pt0;
d0 = *ptd0;
list_loop:
deref_head(d0, vars_within_term_unk);
vars_within_term_nvar:
{
WALK_COMPLEX_TERM()
else 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;
}
}
continue;
derefa_body(d0, ptd0, vars_within_term_unk, vars_within_term_nvar);
}
/* 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_trail_overflow();
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(register CELL *pt0, register CELL *pt0_end, tr_fr_ptr TR0 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;
Term o = TermNil;
CELL *InitialH = HR;
to_visit0 = to_visit;
restart:
while (pt0 < pt0_end) {
register CELL d0;
register CELL *ptd0;
++ pt0;
ptd0 = pt0;
d0 = *ptd0;
list_loop:
deref_head(d0, vars_within_term_unk);
vars_within_term_nvar:
{
WALK_COMPLEX_TERM();
continue;
}
derefa_body(d0, ptd0, vars_within_term_unk, vars_within_term_nvar);
/* 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;
}
/* 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_trail_overflow();
def_aux_overflow();
def_global_overflow();
}
static Term bind_vars_in_complex_term(register CELL *pt0, register CELL *pt0_end, tr_fr_ptr TR0 USES_REGS)
{
register CELL **to_visit0,
**to_visit = (CELL **)Yap_PreAllocCodeSpace();
CELL *InitialH = HR;
to_visit0 = to_visit;
loop:
while (pt0 < pt0_end) {
register CELL d0;
register CELL *ptd0;
++ pt0;
ptd0 = pt0;
d0 = *ptd0;
deref_head(d0, vars_within_term_unk);
vars_within_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;
}
/* store the terms to visit */
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
d0 = ArityOfFunctor(f);
pt0 = ap2;
pt0_end = ap2 + d0;
}
continue;
}
derefa_body(d0, ptd0, vars_within_term_unk, vars_within_term_nvar);
/* 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;
}
/* 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;
}
Yap_ReleasePreAllocCodeSpace((ADDR)to_visit0);
return TermNil;
trail_overflow:
#ifdef RATIONAL_TREES
while (to_visit > to_visit0) {
to_visit -= 3;
pt0 = to_visit[0];
*pt0 = (CELL)to_visit[2];
}
#endif
LOCAL_Error_TYPE = RESOURCE_ERROR_TRAIL;
LOCAL_Error_Size = (TR-TR0)*sizeof(tr_fr_ptr *);
clean_tr(TR0 PASS_REGS);
Yap_ReleasePreAllocCodeSpace((ADDR)to_visit0);
HR = InitialH;
return 0L;
aux_overflow:
LOCAL_Error_Size = (to_visit-to_visit0)*sizeof(CELL **);
#ifdef RATIONAL_TREES
while (to_visit > to_visit0) {
to_visit -= 3;
pt0 = to_visit[0];
*pt0 = (CELL)to_visit[2];
}
#endif
LOCAL_Error_TYPE = RESOURCE_ERROR_AUXILIARY_STACK;
clean_tr(TR0 PASS_REGS);
Yap_ReleasePreAllocCodeSpace((ADDR)to_visit0);
HR = InitialH;
return 0L;
}
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);
continue;
} else if (f == FunctorExecuteInMod) {
found_module = ArgOfTerm(2, t);
t = ArgOfTerm(1, t);
continue;
} 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);
}
static Term non_singletons_in_complex_term(register CELL *pt0, register CELL *pt0_end USES_REGS)
{
int lvl = push_text_stack();
struct non_single_struct_t *to_visit0,
*to_visit = Malloc(1024*sizeof( struct non_single_struct_t)),
*to_visit_max;
register tr_fr_ptr TR0 = TR;
CELL *InitialH = HR;
CELL output = AbsPair(HR);
to_visit0 = to_visit;
to_visit_max = to_visit0+1024;
restart:
while (pt0 < pt0_end) {
register CELL d0;
register CELL *ptd0;
++ pt0;
ptd0 = pt0;
d0 = *ptd0;
list_loop:
deref_head(d0, vars_in_term_unk);
vars_in_term_nvar:
{
WALK_COMPLEX_TERM()
else 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;
}
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) {
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);
} else {
if (!Yap_ExpandPreAllocCodeSpace(0, NULL, TRUE)) {
Yap_Error(RESOURCE_ERROR_AUXILIARY_STACK, ARG1, "overflow in singletons");
return FALSE;
}
}
}
}
static Int ground_complex_term(register CELL *pt0, register CELL *pt0_end USES_REGS)
{
int lvl = push_text_stack();
struct non_single_struct_t *to_visit0,
*to_visit = Malloc(1024*sizeof( struct non_single_struct_t)),
*to_visit_max;
to_visit0 = to_visit;
to_visit_max = to_visit0+1024;
restart:
while (pt0 < pt0_end) {
register CELL d0;
register CELL *ptd0;
++pt0;
ptd0 = pt0;
d0 = *ptd0;
list_loop:
deref_head(d0, vars_in_term_unk);
vars_in_term_nvar:
WALK_COMPLEX_TERM();
continue;
derefa_body(d0, ptd0, vars_in_term_unk, vars_in_term_nvar);
while (to_visit > to_visit0) {
to_visit --;
CELL *ptd0 = to_visit->ptd0;
*ptd0 = to_visit->d0;
}
pop_text_stack(lvl);
return false;
}
/* 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;
if (!Yap_ExpandPreAllocCodeSpace(0, NULL, TRUE)) {
Yap_Error(RESOURCE_ERROR_AUXILIARY_STACK, ARG1, "overflow in ground");
return false;
}
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); \
continue; \
}
static Int numbervars_in_complex_term(register CELL *pt0, register CELL *pt0_end, Int numbv, int singles 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;
register tr_fr_ptr TR0 = TR;
CELL *InitialH = HR;
to_visit0 = to_visit;
to_visit_max = to_visit0+1024;
restart:
while (pt0 < pt0_end) {
register CELL d0;
register CELL *ptd0;
++ pt0;
ptd0 = pt0;
d0 = *ptd0;
list_loop:
deref_head(d0, vars_in_term_unk);
vars_in_term_nvar:
{
WALK_COMPLEX_TERM__({},RENUMBER_SINGLES);
continue;
}
derefa_body(d0, ptd0, vars_in_term_unk, vars_in_term_nvar);
/* 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;
}
/* 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_trail_overflow();
def_aux_overflow();
def_global_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 (IsVarTerm(t)) {
CELL *ptd0 = VarOfTerm(t);
TrailTerm(TR++) = (CELL)ptd0;
if (handle_singles) {
*ptd0 = numbervar_singleton( PASS_REGS1 );
return numbv;
} else {
*ptd0 = numbervar(numbv PASS_REGS);
return numbv+1;
}
} else if (IsPrimitiveTerm(t)) {
return numbv;
} else if (IsPairTerm(t)) {
out = numbervars_in_complex_term(RepPair(t)-1,
RepPair(t)+1, numbv, handle_singles PASS_REGS);
} else {
Functor f = FunctorOfTerm(t);
out = numbervars_in_complex_term(RepAppl(t),
RepAppl(t)+
ArityOfFunctor(f), numbv, handle_singles PASS_REGS);
}
if (out < numbv) {
if (!expand_vts( 3 PASS_REGS ))
return FALSE;
goto restart;
}
}
/** @pred numbervars( _T_,+ _N1_,- _Nn_)
Instantiates each variable in term _T_ to a term of the form:
`$VAR( _I_)`, with _I_ increasing from _N1_ to _Nn_.
*/
static Int
p_numbervars( USES_REGS1 )
{
Term t2 = Deref(ARG2);
Int out;
if (IsVarTerm(t2)) {
Yap_Error(INSTANTIATION_ERROR,t2,"numbervars/3");
return FALSE;
}
if (!IsIntegerTerm(t2)) {
Yap_Error(TYPE_ERROR_INTEGER,t2,"numbervars/3");
return(FALSE);
}
if ((out = Yap_NumberVars(ARG1, IntegerOfTerm(t2), FALSE)) < 0)
return FALSE;
return Yap_unify(ARG3, MkIntegerTerm(out));
}
void Yap_InitTermCPreds(void)
{
Yap_InitCPred("term_variables", 2, p_term_variables, 0);
Yap_InitCPred("term_variables", 3, p_term_variables3, 0);
Yap_InitCPred("$variables_in_term", 3, p_variables_in_term, 0);
Yap_InitCPred("$free_variables_in_term", 3, p_free_variables_in_term, 0);
Yap_InitCPred("term_attvars", 2, p_term_attvars, 0);
CurrentModule = TERMS_MODULE;
Yap_InitCPred("variable_in_term", 2, p_var_in_term, 0);
Yap_InitCPred("variables_within_term", 3, p_variables_within_term, 0);
Yap_InitCPred("new_variables_in_term", 3, p_new_variables_in_term, 0);
CurrentModule = PROLOG_MODULE;
Yap_InitCPred("$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);
}