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yap-6.3/C/write.c
vsc 47765f7739 WIN32 support
git-svn-id: https://yap.svn.sf.net/svnroot/yap/trunk@1790 b08c6af1-5177-4d33-ba66-4b1c6b8b522a
2007-01-28 14:26:37 +00:00

824 lines
21 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: write.c *
* Last rev: *
* mods: *
* comments: Writing a Prolog Term *
* *
*************************************************************************/
#ifdef SCCS
static char SccsId[] = "%W% %G%";
#endif
#include "Yap.h"
#include "Yatom.h"
#include "Heap.h"
#include "yapio.h"
#if COROUTINING
#include "attvar.h"
#endif
#if HAVE_STRING_H
#include <string.h>
#endif
#if HAVE_CTYPE_H
#include <ctype.h>
#endif
/* describe the type of the previous term to have been written */
typedef enum {
separator, /* the previous term was a separator like ',', ')', ... */
alphanum, /* the previous term was an atom or number */
symbol /* the previous term was a symbol like +, -, *, .... */
} wtype;
static wtype lastw;
typedef int (*wrf) (int, wchar_t);
typedef struct write_globs {
wrf writewch;
int Quote_illegal, Ignore_ops, Handle_vars, Use_portray;
int keep_terms;
UInt MaxDepth, MaxList, MaxArgs;
} wglbs;
STATIC_PROTO(void wrputn, (Int, wrf));
STATIC_PROTO(void wrputs, (char *, wrf));
STATIC_PROTO(void wrputf, (Float, wrf));
STATIC_PROTO(void wrputref, (CODEADDR, int, wrf));
STATIC_PROTO(int legalAtom, (char *));
STATIC_PROTO(int LeftOpToProtect, (Atom, int));
STATIC_PROTO(int RightOpToProtect, (Atom, int));
STATIC_PROTO(wtype AtomIsSymbols, (char *));
STATIC_PROTO(void putAtom, (Atom, int, wrf));
STATIC_PROTO(void writeTerm, (Term, int, int, int, struct write_globs *));
#define wrputc(X,WF) ((*WF)(Yap_c_output_stream,X)) /* writes a character */
static void
wrputn(Int n, wrf writewch) /* writes an integer */
{
char s[256], *s1=s; /* that should be enough for most integers */
if (n < 0) {
if (lastw == symbol)
wrputc(' ', writewch);
} else {
if (lastw == alphanum)
wrputc(' ', writewch);
}
#if HAVE_SNPRINTF
#if SHORT_INTS
snprintf(s, 256, "%ld", n);
#else
snprintf(s, 256, "%d", n);
#endif
#else
#if SHORT_INTS
sprintf(s, "%ld", n);
#else
sprintf(s, "%d", n);
#endif
#endif
while (*s1)
wrputc(*s1++, writewch);
lastw = alphanum;
}
static void
wrputs(char *s, wrf writewch) /* writes a string */
{
while (*s)
wrputc(*s++, writewch);
}
static void
wrputws(wchar_t *s, wrf writewch) /* writes a string */
{
while (*s)
wrputc(*s++, writewch);
}
static void
wrputf(Float f, wrf writewch) /* writes a float */
{
char s[256], *pt = s, ch;
if (f < 0) {
if (lastw == symbol)
wrputc(' ', writewch);
} else {
if (lastw == alphanum)
wrputc(' ', writewch);
}
lastw = alphanum;
// sprintf(s, "%.15g", f);
sprintf(s, RepAtom(FloatFormat)->StrOfAE, f);
while (*pt == ' ')
pt++;
if (*pt == 'i' || *pt == 'n') /* inf or nan */ {
wrputc('(', writewch);
wrputc('+', writewch);
wrputs(pt, writewch);
wrputc(')', writewch);
} else {
wrputs(pt, writewch);
}
if (*pt == '-') pt++;
while ((ch = *pt) != '\0') {
if (ch < '0' || ch > '9')
return;
pt++;
}
wrputs(".0", writewch);
}
static void
wrputref(CODEADDR ref, int Quote_illegal, wrf writewch) /* writes a data base reference */
{
char s[256];
putAtom(AtomDBRef, Quote_illegal, writewch);
#if SHORT_INTS
sprintf(s, "(0x%p,0)", ref);
#elif __linux__
sprintf(s, "(%p,0)", ref);
#else
sprintf(s, "(0x%p,0)", ref);
#endif
wrputs(s, writewch);
lastw = alphanum;
}
static int
legalAtom(char *s) /* Is this a legal atom ? */
{
register int ch = *s;
if (ch == '\0')
return(FALSE);
if (Yap_chtype[ch] != LC) {
if (ch == '[')
return (*++s == ']' && !(*++s));
else if (ch == '{')
return (*++s == '}' && !(*++s));
else if (Yap_chtype[ch] == SL)
return (!*++s);
else if ((ch == ',' || ch == '.') && !s[1])
return (FALSE);
else
while (ch) {
if (Yap_chtype[ch] != SY) return (FALSE);
ch = *++s;
}
return (TRUE);
} else
while ((ch = *++s) != 0)
if (Yap_chtype[ch] > NU)
return (FALSE);
return (TRUE);
}
static int LeftOpToProtect(Atom at, int p)
{
int op, rp;
OpEntry *opinfo = Yap_GetOpProp(at);
return(opinfo && Yap_IsPrefixOp(opinfo, &op, &rp) );
}
static int RightOpToProtect(Atom at, int p)
{
int op, lp;
OpEntry *opinfo = Yap_GetOpProp(at);
return(opinfo && Yap_IsPosfixOp(opinfo, &op, &lp) );
}
static wtype
AtomIsSymbols(char *s) /* Is this atom just formed by symbols ? */
{
int ch;
if (Yap_chtype[(int)s[0]] == SL && s[1] == '\0')
return(separator);
while ((ch = *s++) != '\0') {
if (Yap_chtype[ch] != SY)
return(alphanum);
}
return(symbol);
}
static void
putAtom(Atom atom, int Quote_illegal, wrf writewch) /* writes an atom */
{
char *s = RepAtom(atom)->StrOfAE;
wtype atom_or_symbol = AtomIsSymbols(s);
/* #define CRYPT_FOR_STEVE 1*/
#ifdef CRYPT_FOR_STEVE
if (Yap_GetValue(Yap_LookupAtom("crypt_atoms")) != TermNil && Yap_GetAProp(atom, OpProperty) == NIL) {
char s[16];
sprintf(s,"x%x", (CELL)s);
wrputs(s, writewch);
return;
}
#endif
if (IsWideAtom(atom)) {
wchar_t *ws = (wchar_t *)s;
if (Quote_illegal) {
wrputc('\'', writewch);
while (*ws) {
wchar_t ch = *ws++;
wrputc(ch, writewch);
if (ch == '\\' && yap_flags[CHARACTER_ESCAPE_FLAG] != CPROLOG_CHARACTER_ESCAPES)
wrputc('\\', writewch); /* be careful about backslashes */
else if (ch == '\'')
wrputc('\'', writewch); /* be careful about quotes */
}
wrputc('\'', writewch);
} else {
wrputws(ws, writewch);
}
return;
}
if (lastw == atom_or_symbol && atom_or_symbol != separator /* solo */)
wrputc(' ', writewch);
lastw = atom_or_symbol;
if (!legalAtom(s) && Quote_illegal) {
wrputc('\'', writewch);
while (*s) {
int ch = *s++;
wrputc(ch, writewch);
if (ch == '\\' && yap_flags[CHARACTER_ESCAPE_FLAG] != CPROLOG_CHARACTER_ESCAPES)
wrputc('\\', writewch); /* be careful about backslashes */
else if (ch == '\'')
wrputc('\'', writewch); /* be careful about quotes */
}
wrputc('\'', writewch);
} else {
wrputs(s, writewch);
}
}
static int
IsStringTerm(Term string) /* checks whether this is a string */
{
if (IsVarTerm(string)) return(FALSE);
do {
Term hd;
int ch;
if (!IsPairTerm(string)) return(FALSE);
hd = HeadOfTerm(string);
if (IsVarTerm(hd)) return(FALSE);
if (!IsIntTerm(hd)) return(FALSE);
ch = IntOfTerm(HeadOfTerm(string));
if ((ch < ' ' || ch > MAX_ISO_LATIN1) && ch != '\n' && ch != '\t')
return(FALSE);
string = TailOfTerm(string);
if (IsVarTerm(string)) return(FALSE);
} while (string != TermNil);
return(TRUE);
}
static void
putString(Term string, wrf writewch) /* writes a string */
{
wrputc('"', writewch);
while (string != TermNil) {
int ch = IntOfTerm(HeadOfTerm(string));
wrputc(ch, writewch);
if (ch == '\\' && yap_flags[CHARACTER_ESCAPE_FLAG] != CPROLOG_CHARACTER_ESCAPES)
wrputc('\\', writewch); /* be careful about backslashes */
else if (ch == '"')
wrputc('"', writewch); /* be careful about quotes */
string = TailOfTerm(string);
}
wrputc('"', writewch);
lastw = alphanum;
}
static void
putUnquotedString(Term string, wrf writewch) /* writes a string */
{
while (string != TermNil) {
int ch = IntOfTerm(HeadOfTerm(string));
wrputc(ch, writewch);
string = TailOfTerm(string);
}
lastw = alphanum;
}
static void
write_var(CELL *t, struct write_globs *wglb)
{
if (lastw == alphanum) {
wrputc(' ', wglb->writewch);
}
wrputc('_', wglb->writewch);
/* make sure we don't get no creepy spaces where they shouldn't be */
lastw = separator;
if (CellPtr(t) < H0) {
#if COROUTINING
#if DEBUG
if (Yap_Portray_delays) {
exts ext = ExtFromCell(t);
Yap_Portray_delays = FALSE;
if (ext == attvars_ext) {
attvar_record *attv = (attvar_record *)t;
long sl = 0;
Term l = attv->Atts;
wrputs("$AT(",wglb->writewch);
write_var(t, wglb);
wrputc(',', wglb->writewch);
if (wglb->keep_terms) {
/* garbage collection may be called */
sl = Yap_InitSlot((CELL)attv);
}
writeTerm((Term)&(attv->Value), 999, 1, FALSE, wglb);
wrputc(',', wglb->writewch);
writeTerm(l, 999, 1, FALSE, wglb);
if (wglb->keep_terms) {
attv = (attvar_record *)Yap_GetFromSlot(sl);
Yap_RecoverSlots(1);
}
wrputc(')', wglb->writewch);
}
Yap_Portray_delays = TRUE;
return;
}
#endif
wrputc('D', wglb->writewch);
wrputn((Int) ((attvar_record *)H0-(attvar_record *)t),wglb->writewch);
#endif
} else {
wrputn(((Int) (t- H0)),wglb->writewch);
}
}
static void
writeTerm(Term t, int p, int depth, int rinfixarg, struct write_globs *wglb)
/* term to write */
/* context priority */
{
if (wglb->MaxDepth != 0 && depth > wglb->MaxDepth) {
putAtom(Yap_LookupAtom("..."), wglb->Quote_illegal, wglb->writewch);
return;
}
if (EX != 0)
return;
t = Deref(t);
if (IsVarTerm(t)) {
write_var((CELL *)t, wglb);
} else if (IsIntTerm(t)) {
wrputn((Int) IntOfTerm(t),wglb->writewch);
} else if (IsAtomTerm(t)) {
putAtom(AtomOfTerm(t), wglb->Quote_illegal, wglb->writewch);
} else if (IsPairTerm(t)) {
int eldepth = 1;
Term ti;
if (wglb->Use_portray) {
Term targs[1];
Term old_EX = 0L;
long sl = 0;
targs[0] = t;
Yap_PutValue(AtomPortray, MkAtomTerm(AtomNil));
if (EX != 0L) old_EX = EX;
sl = Yap_InitSlot(t);
Yap_execute_goal(Yap_MkApplTerm(FunctorPortray, 1, targs), 0, 1);
t = Yap_GetFromSlot(sl);
Yap_RecoverSlots(1);
if (old_EX != 0L) EX = old_EX;
if (Yap_GetValue(AtomPortray) == MkAtomTerm(AtomTrue))
return;
}
if (yap_flags[WRITE_QUOTED_STRING_FLAG] && IsStringTerm(t)) {
putString(t, wglb->writewch);
} else {
wrputc('[', wglb->writewch);
lastw = separator;
while (1) {
int new_depth = depth + 1;
long sl= 0;
if (wglb->MaxList && eldepth > wglb->MaxList) {
putAtom(Yap_LookupAtom("..."), wglb->Quote_illegal, wglb->writewch);
wrputc(']', wglb->writewch);
lastw = separator;
return;
} else {
eldepth++;
}
if (wglb->keep_terms) {
/* garbage collection may be called */
sl = Yap_InitSlot(t);
}
writeTerm(HeadOfTermCell(t), 999, new_depth, FALSE, wglb);
if (wglb->keep_terms) {
t = Yap_GetFromSlot(sl);
Yap_RecoverSlots(1);
}
ti = TailOfTerm(t);
if (IsVarTerm(ti))
break;
if (!IsPairTerm(ti))
break;
t = ti;
wrputc(',', wglb->writewch);
lastw = separator;
}
if (ti != MkAtomTerm(AtomNil)) {
wrputc('|', wglb->writewch);
lastw = separator;
writeTerm(TailOfTermCell(t), 999, depth + 1, FALSE, wglb);
}
wrputc(']', wglb->writewch);
lastw = separator;
}
} else { /* compound term */
Functor functor = FunctorOfTerm(t);
int Arity;
Atom atom;
OpEntry *opinfo;
int op, lp, rp;
if (IsExtensionFunctor(functor)) {
switch((CELL)functor) {
case (CELL)FunctorDouble:
wrputf(FloatOfTerm(t),wglb->writewch);
return;
case (CELL)FunctorDBRef:
wrputref(RefOfTerm(t), wglb->Quote_illegal, wglb->writewch);
return;
case (CELL)FunctorLongInt:
wrputn(LongIntOfTerm(t),wglb->writewch);
return;
#ifdef USE_GMP
case (CELL)FunctorBigInt:
{
MP_INT *big = Yap_BigIntOfTerm(t);
char *s = (char *)TR;
if (s+2+mpz_sizeinbase(big, 10) >= Yap_TrailTop) {
s = (char *)H;
if (s+2+mpz_sizeinbase(big, 10) >= (char *)ASP) {
return;
}
}
if (!s)
return;
if (mpz_sgn(big) < 0) {
if (lastw == symbol)
wrputc(' ', wglb->writewch);
} else {
if (lastw == alphanum)
wrputc(' ', wglb->writewch);
}
mpz_get_str(s, 10, big);
wrputs(s,wglb->writewch);
}
return;
#endif
}
}
Arity = ArityOfFunctor(functor);
atom = NameOfFunctor(functor);
opinfo = Yap_GetOpProp(atom);
#ifdef SFUNC
if (Arity == SFArity) {
int argno = 1;
CELL *p = ArgsOfSFTerm(t);
putAtom(atom, wglb->Quote_illegal, wglb->writewch);
wrputc('(', wglb->writewch);
lastw = separator;
while (*p) {
long sl = 0;
while (argno < *p) {
wrputc('_', wglb->writewch), wrputc(',', wglb->writewch);
++argno;
}
*p++;
lastw = separator;
/* cannot use the term directly with the SBA */
if (wglb->keep_terms) {
/* garbage collection may be called */
sl = Yap_InitSlot((CELL)p);
}
writeTerm(Deref(p++), 999, depth + 1, FALSE, wglb);
if (wglb->keep_terms) {
/* garbage collection may be called */
p = (CELL *)Yap_GetFromSlot(sl);
Yap_RecoverSlots(1);
}
if (*p)
wrputc(',', wglb->writewch);
argno++;
}
wrputc(')', wglb->writewch);
lastw = separator;
return;
}
#endif
if (wglb->Use_portray) {
Term targs[1];
Term old_EX = 0L;
long sl = 0;
targs[0] = t;
Yap_PutValue(AtomPortray, MkAtomTerm(AtomNil));
if (EX != 0L) old_EX = EX;
sl = Yap_InitSlot(t);
Yap_execute_goal(Yap_MkApplTerm(FunctorPortray, 1, targs),0, 1);
t = Yap_GetFromSlot(sl);
Yap_RecoverSlots(1);
if (old_EX != 0L) EX = old_EX;
if (Yap_GetValue(AtomPortray) == MkAtomTerm(AtomTrue) || EX != 0L)
return;
}
if (!wglb->Ignore_ops &&
Arity == 1 && opinfo && Yap_IsPrefixOp(opinfo, &op,
&rp)
#ifdef DO_NOT_WRITE_PLUS_AND_MINUS_AS_PREFIX
&&
/* never write '+' and '-' as infix
operators */
( (RepAtom(atom)->StrOfAE[0] != '+' &&
RepAtom(atom)->StrOfAE[0] != '-') ||
RepAtom(atom)->StrOfAE[1] )
#endif /* DO_NOT_WRITE_PLUS_AND_MINUS_AS_PREFIX */
) {
Term tright = ArgOfTerm(1, t);
int bracket_right =
!IsVarTerm(tright) && IsAtomTerm(tright) &&
RightOpToProtect(AtomOfTerm(tright), rp);
if (op > p) {
/* avoid stuff such as \+ (a,b) being written as \+(a,b) */
if (lastw != separator && !rinfixarg)
wrputc(' ', wglb->writewch);
wrputc('(', wglb->writewch);
lastw = separator;
}
putAtom(atom, wglb->Quote_illegal, wglb->writewch);
if (bracket_right) {
wrputc('(', wglb->writewch);
lastw = separator;
}
writeTerm(ArgOfTermCell(1,t), rp, depth + 1, FALSE, wglb);
if (bracket_right) {
wrputc(')', wglb->writewch);
lastw = separator;
}
if (op > p) {
wrputc(')', wglb->writewch);
lastw = separator;
}
} else if (!wglb->Ignore_ops &&
Arity == 1 && opinfo && Yap_IsPosfixOp(opinfo, &op, &lp)) {
Term tleft = ArgOfTerm(1, t);
long sl = 0;
int bracket_left =
!IsVarTerm(tleft) && IsAtomTerm(tleft) &&
LeftOpToProtect(AtomOfTerm(tleft), lp);
if (op > p) {
/* avoid stuff such as \+ (a,b) being written as \+(a,b) */
if (lastw != separator && !rinfixarg)
wrputc(' ', wglb->writewch);
wrputc('(', wglb->writewch);
lastw = separator;
}
if (bracket_left) {
wrputc('(', wglb->writewch);
lastw = separator;
}
if (wglb->keep_terms) {
/* garbage collection may be called */
sl = Yap_InitSlot(t);
}
writeTerm(ArgOfTermCell(1,t), lp, depth + 1, rinfixarg, wglb);
if (wglb->keep_terms) {
/* garbage collection may be called */
t = Yap_GetFromSlot(sl);
Yap_RecoverSlots(1);
}
if (bracket_left) {
wrputc(')', wglb->writewch);
lastw = separator;
}
putAtom(atom, wglb->Quote_illegal, wglb->writewch);
if (op > p) {
wrputc(')', wglb->writewch);
lastw = separator;
}
} else if (!wglb->Ignore_ops &&
Arity == 2 && opinfo && Yap_IsInfixOp(opinfo, &op, &lp,
&rp) ) {
Term tleft = ArgOfTerm(1, t);
Term tright = ArgOfTerm(2, t);
long sl = 0;
int bracket_left =
!IsVarTerm(tleft) && IsAtomTerm(tleft) &&
LeftOpToProtect(AtomOfTerm(tleft), lp);
int bracket_right =
!IsVarTerm(tright) && IsAtomTerm(tright) &&
RightOpToProtect(AtomOfTerm(tright), rp);
if (op > p) {
/* avoid stuff such as \+ (a,b) being written as \+(a,b) */
if (lastw != separator && !rinfixarg)
wrputc(' ', wglb->writewch);
wrputc('(', wglb->writewch);
lastw = separator;
}
if (bracket_left) {
wrputc('(', wglb->writewch);
lastw = separator;
}
if (wglb->keep_terms) {
/* garbage collection may be called */
sl = Yap_InitSlot(t);
}
writeTerm(ArgOfTermCell(1, t), lp, depth + 1, rinfixarg, wglb);
if (wglb->keep_terms) {
/* garbage collection may be called */
t = Yap_GetFromSlot(sl);
Yap_RecoverSlots(1);
}
if (bracket_left) {
wrputc(')', wglb->writewch);
lastw = separator;
}
/* avoid quoting commas */
if (strcmp(RepAtom(atom)->StrOfAE,","))
putAtom(atom, wglb->Quote_illegal, wglb->writewch);
else {
wrputc(',', wglb->writewch);
lastw = separator;
}
if (bracket_right) {
wrputc('(', wglb->writewch);
lastw = separator;
}
writeTerm(ArgOfTermCell(2, t), rp, depth + 1, TRUE, wglb);
if (bracket_right) {
wrputc(')', wglb->writewch);
lastw = separator;
}
if (op > p) {
wrputc(')', wglb->writewch);
lastw = separator;
}
} else if (wglb->Handle_vars && functor == FunctorVar) {
Term ti = ArgOfTerm(1, t);
if (lastw == alphanum) {
wrputc(' ', wglb->writewch);
}
if (!IsVarTerm(ti) && (IsIntTerm(ti) || IsStringTerm(ti))) {
if (IsIntTerm(ti)) {
Int k = IntOfTerm(ti);
if (k == -1) {
wrputc('_', wglb->writewch);
lastw = alphanum;
return;
} else {
wrputc((k % 26) + 'A', wglb->writewch);
if (k >= 26) {
/* make sure we don't get confused about our context */
lastw = separator;
wrputn( k / 26 ,wglb->writewch);
} else
lastw = alphanum;
}
} else {
putUnquotedString(ti, wglb->writewch);
}
} else {
long sl = 0;
wrputs("'$VAR'(",wglb->writewch);
lastw = separator;
if (wglb->keep_terms) {
/* garbage collection may be called */
sl = Yap_InitSlot(t);
}
writeTerm(ArgOfTermCell(1,t), 999, depth + 1, FALSE, wglb);
if (wglb->keep_terms) {
/* garbage collection may be called */
t = Yap_GetFromSlot(sl);
Yap_RecoverSlots(1);
}
wrputc(')', wglb->writewch);
lastw = separator;
}
} else if (functor == FunctorBraces) {
wrputc('{', wglb->writewch);
lastw = separator;
writeTerm(ArgOfTermCell(1, t), 1200, depth + 1, FALSE, wglb);
wrputc('}', wglb->writewch);
lastw = separator;
} else if (atom == AtomArray) {
long sl = 0;
wrputc('{', wglb->writewch);
lastw = separator;
for (op = 1; op <= Arity; ++op) {
if (op == wglb->MaxArgs) {
wrputc('.', wglb->writewch);
wrputc('.', wglb->writewch);
wrputc('.', wglb->writewch);
break;
}
if (wglb->keep_terms) {
/* garbage collection may be called */
sl = Yap_InitSlot(t);
}
writeTerm(ArgOfTermCell(op, t), 999, depth + 1, FALSE, wglb);
if (wglb->keep_terms) {
/* garbage collection may be called */
t = Yap_GetFromSlot(sl);
Yap_RecoverSlots(1);
}
if (op != Arity) {
wrputc(',', wglb->writewch);
lastw = separator;
}
}
wrputc('}', wglb->writewch);
lastw = separator;
} else {
putAtom(atom, wglb->Quote_illegal, wglb->writewch);
lastw = separator;
wrputc('(', wglb->writewch);
for (op = 1; op <= Arity; ++op) {
long sl = 0;
if (op == wglb->MaxArgs) {
wrputc('.', wglb->writewch);
wrputc('.', wglb->writewch);
wrputc('.', wglb->writewch);
break;
}
if (wglb->keep_terms) {
/* garbage collection may be called */
sl = Yap_InitSlot(t);
}
writeTerm(ArgOfTermCell(op, t), 999, depth + 1, FALSE, wglb);
if (wglb->keep_terms) {
/* garbage collection may be called */
t = Yap_GetFromSlot(sl);
Yap_RecoverSlots(1);
}
if (op != Arity) {
wrputc(',', wglb->writewch);
lastw = separator;
}
}
wrputc(')', wglb->writewch);
lastw = separator;
}
}
}
void
Yap_plwrite(Term t, int (*mywrite) (int, wchar_t), int flags)
/* term to be written */
/* consumer */
/* write options */
{
struct write_globs wglb;
wglb.writewch = mywrite;
lastw = separator;
wglb.Quote_illegal = flags & Quote_illegal_f;
wglb.Handle_vars = flags & Handle_vars_f;
wglb.Use_portray = flags & Use_portray_f;
wglb.MaxDepth = max_depth;
wglb.MaxList = max_list;
wglb.MaxArgs = max_write_args;
/* notice: we must have ASP well set when using portray, otherwise
we cannot make recursive Prolog calls */
wglb.keep_terms = (flags & (Use_portray_f|To_heap_f));
wglb.Ignore_ops = flags & Ignore_ops_f;
/* protect slots for portray */
writeTerm(t, 1200, 1, FALSE, &wglb);
}