packages/cpp/SWI-cpp.h

/*  Part of SWI-Prolog

    Author:        Jan Wielemaker
    E-mail:        J.Wielemaker@vu.nl
    WWW:           http://www.swi-prolog.org
    Copyright (c)  2000-2020, University of Amsterdam
                              Vu University Amsterdam
    All rights reserved.

    Redistribution and use in source and binary forms, with or without
    modification, are permitted provided that the following conditions
    are met:

    1. Redistributions of source code must retain the above copyright
       notice, this list of conditions and the following disclaimer.

    2. Redistributions in binary form must reproduce the above copyright
       notice, this list of conditions and the following disclaimer in
       the documentation and/or other materials provided with the
       distribution.

    THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
    "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
    LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
    FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
    COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
    INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
    BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
    LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
    CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
    LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
    ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
    POSSIBILITY OF SUCH DAMAGE.
*/

#ifndef _SWI_CPP_H
#define _SWI_CPP_H

#include <SWI-Prolog.h>
#include <string.h>
#include <wchar.h>
#if !(defined(__APPLE__) || defined(__FreeBSD__))
#include <stdlib.h>
#endif

#ifdef __BORLANDC__
#define __inline inline
#endif

/* Define as 1 if undefined or defined as empty */
#if !defined(PL_ARITY_AS_SIZE) || (0-PL_ARITY_AS_SIZE-1)==1
#undef PL_ARITY_AS_SIZE
#define PL_ARITY_AS_SIZE 1
#endif

#ifndef ARITY_T
#if PL_ARITY_AS_SIZE
#define ARITY_T size_t
#else
#define ARITY_T int
#endif
#endif

class PlTerm;
class PlTermv;

		 /*******************************
		 *	 PROLOG CONSTANTS	*
		 *******************************/

class PlFunctor
{
public:
  functor_t functor;

  PlFunctor(const char *name, ARITY_T arity)
  { functor = PL_new_functor(PL_new_atom(name), arity);
  }
  PlFunctor(const wchar_t *name, ARITY_T arity)
  { functor = PL_new_functor(PL_new_atom_wchars(wcslen(name), name), arity);
  }
};


class PlAtom
{
public:
  atom_t handle;

  PlAtom(atom_t h)
  { handle = h;
  }
  PlAtom(const char *text)
  { handle = PL_new_atom(text);
  }
  PlAtom(const wchar_t *text)
  { handle = PL_new_atom_wchars(wcslen(text), text);
  }
  PlAtom(const PlTerm &t);

  operator const char *(void) const
  { return PL_atom_chars(handle);
  }
  operator const wchar_t *(void) const
  { return PL_atom_wchars(handle, NULL);
  }

  int operator ==(const char *s) const
  { return strcmp(s, PL_atom_chars(handle)) == 0;
  }
  int operator ==(const wchar_t *s) const
  { return wcscmp(s, PL_atom_wchars(handle, NULL)) == 0;
  }
  int operator ==(const PlAtom &a) const
  { return handle == a.handle;
  }
  int operator ==(atom_t to) const
  { return handle == to;
  }
};

		 /*******************************
		 *     GENERIC PROLOG TERM	*
		 *******************************/


class PlTerm
{
public:
  term_t ref;

  PlTerm();
  PlTerm(const PlTerm &other) : ref(other.ref) {}
  PlTerm(term_t t)
  { ref = t;
  }

					/* C --> PlTerm */
  PlTerm(const char *text);
  PlTerm(const wchar_t *text);
  PlTerm(long val);
  PlTerm(double val);
  PlTerm(const PlAtom &a);
  PlTerm(void *ptr);

					/* PlTerm --> C */
  operator term_t(void) const
  { return ref;
  }
  operator char *(void) const;
  operator wchar_t *(void) const;
  operator long(void) const;
  operator int(void) const;
  operator double(void) const;
  operator PlAtom(void) const;
  operator void *(void) const;

  int type() const
  { return PL_term_type(ref);
  }

					/* Compounds */
  PlTerm operator [](ARITY_T index) const;
  ARITY_T arity() const;
  const char *name() const;

					/* UNIFY */
  int operator =(const PlTerm &t2);	/* term */
  int operator =(const PlAtom &a);	/* atom */
  int operator =(const char *v);	/* atom (from char *) */
  int operator =(const wchar_t *v);	/* atom (from wchar_t *) */
  int operator =(long v);		/* integer */
  int operator =(int v);		/* integer */
  int operator =(double v);		/* float */
  int operator =(const PlFunctor &f);	/* functor */

					/* Comparison standard order terms */
  int operator ==(const PlTerm &t2) const
  { return PL_compare(ref, t2.ref) == 0;
  }
  int operator !=(const PlTerm &t2) const
  { return PL_compare(ref, t2.ref) != 0;
  }
  int operator <(const PlTerm &t2) const
  { return PL_compare(ref, t2.ref) < 0;
  }
  int operator >(const PlTerm &t2) const
  { return PL_compare(ref, t2.ref) > 0;
  }
  int operator <=(const PlTerm &t2) const
  { return PL_compare(ref, t2.ref) <= 0;
  }
  int operator >=(const PlTerm &t2) const
  { return PL_compare(ref, t2.ref) >= 0;
  }
					/* comparison (long) */
  int operator ==(long v) const;
  int operator !=(long v) const;
  int operator <(long v) const;
  int operator >(long v) const;
  int operator <=(long v) const;
  int operator >=(long v) const;

					/* comparison (string) */
  int operator ==(const char *s) const;
  int operator ==(const wchar_t *s) const;
  int operator ==(const PlAtom &a) const;
};


		 /*******************************
		 *	   TERM VECTOR		*
		 *******************************/

class PlTermv
{
public:
  term_t a0;
  int    size;

  PlTermv(int n)
  { a0   = PL_new_term_refs(n);
    size = n;
  }
  PlTermv(int n, term_t t0)
  { a0   = t0;
    size = n;
  }

					/* create from args */
  PlTermv(PlTerm m0);
  PlTermv(PlTerm m0, PlTerm m1);
  PlTermv(PlTerm m0, PlTerm m1, PlTerm m2);
  PlTermv(PlTerm m0, PlTerm m1, PlTerm m2, PlTerm m3);
  PlTermv(PlTerm m0, PlTerm m1, PlTerm m2, PlTerm m3, PlTerm m4);

  PlTerm operator [](int n) const;
};

		 /*******************************
		 *	 SPECIALISED TERMS	*
		 *******************************/

class PlCompound : public PlTerm
{
public:

  PlCompound(const char *text);
  PlCompound(const wchar_t *text);
  PlCompound(const char *functor, const PlTermv &args);
  PlCompound(const wchar_t *functor, const PlTermv &args);
};


class PlString : public PlTerm
{
public:

  PlString(const char *text);
  PlString(const char *text, size_t len);
  PlString(const wchar_t *text);
  PlString(const wchar_t *text, size_t len);
};


class PlCodeList : public PlTerm
{
public:

  PlCodeList(const char *text);
  PlCodeList(const wchar_t *text);
};


class PlCharList : public PlTerm
{
public:

  PlCharList(const char *text);
  PlCharList(const wchar_t *text);
};


		 /*******************************
		 *	      EXCEPTIONS	*
		 *******************************/

class PlException : public PlTerm
{
public:
  PlException()
  { term_t ex = PL_exception(0);
    if ( ex )
      ref = ex;
    else
      PL_fatal_error("No exception");
  }

  PlException(const PlTerm &t)
  { ref = t.ref;
  }

  operator const char *(void);
  operator const wchar_t *(void);

  int plThrow()
  { return PL_raise_exception(ref);
  }

  void cppThrow();
};


class PlTypeError : public PlException
{
public:

  PlTypeError(const PlTerm &t) : PlException(t) {}

  PlTypeError(const char *expected, PlTerm actual) :
    PlException(PlCompound("error",
			   PlTermv(PL_is_variable(actual.ref) ?
				     PlTerm("instantiation_error") :
				     PlCompound("type_error",
						PlTermv(expected, actual)),
				   PlTerm())))
  {
  }
};


class PlDomainError : public PlException
{
public:

  PlDomainError(const PlTerm &t) : PlException(t) {}

  PlDomainError(const char *expected, PlTerm actual) :
    PlException(PlCompound("error",
			   PlTermv(PlCompound("domain_error",
					      PlTermv(expected, actual)),
				   PlTerm())))
  {
  }
};


class PlInstantiationError : public PlException
{
public:

  PlInstantiationError(const PlTerm &t) :
  PlException(PL_is_variable(t) ?
	      PlCompound("error",
			 PlTermv("instantiation_error",
				 t)) : t) {}

  PlInstantiationError() :
    PlException(PlCompound("error",
			   PlTermv("instantiation_error",
				   PlTerm())))
  {
  }
};


class PlExistenceError : public PlException
{
public:

  PlExistenceError(const PlTerm &t) : PlException(t) {}

  PlExistenceError(const char *type, PlTerm actual) :
    PlException(PlCompound("error",
			   PlTermv(PlCompound("existence_error",
					      PlTermv(type, actual)),
				   PlTerm())))
  {
  }
};


class PlPermissionError : public PlException
{
public:

  PlPermissionError(const PlTerm &t) : PlException(t) {}

  PlPermissionError(const char *op, const char *type, PlTerm obj) :
    PlException(PlCompound("error",
			   PlTermv(PlCompound("permission_error",
					      PlTermv(op, type, obj)),
				   PlTerm())))
  {
  }
};


class PlResourceError : public PlException
{
public:
  PlResourceError() : PlException() {}

  PlResourceError(const PlTerm &t) : PlException(t) {}

  PlResourceError(const char *resource) :
    PlException(PlCompound("error",
			   PlTermv(PlCompound("resource_error",
					      PlTermv(PlTerm(resource))),
				   PlTerm())))
  {
  }
};


class PlTermvDomainError : public PlException
{
public:

  PlTermvDomainError(int size, int n) :
    PlException(PlCompound("error",
			   PlTermv(PlCompound("domain_error",
					      PlTermv(PlCompound("argv",
								 size),
						      PlTerm((long)n))),
				   PlTerm())))
  {
  }
};


		 /*******************************
		 *     PLTERM IMPLEMENTATION	*
		 *******************************/

__inline
PlTerm::PlTerm()
{ if ( !(ref = PL_new_term_ref()) )
    throw PlResourceError();
}

__inline
PlTerm::PlTerm(const char *text)
{ if ( !(ref = PL_new_term_ref()) ||
       !PL_put_atom_chars(ref, text) )
    throw PlResourceError();
}

__inline
PlTerm::PlTerm(const wchar_t *text)
{ if ( !(ref = PL_new_term_ref()) ||
       !PL_unify_wchars(ref, PL_ATOM, (size_t)-1, text) )
    throw PlResourceError();
}

__inline
PlTerm::PlTerm(long val)
{ if ( !(ref = PL_new_term_ref()) ||
       !PL_put_integer(ref, val) )
    throw PlResourceError();
}

__inline
PlTerm::PlTerm(double val)
{ if ( !(ref = PL_new_term_ref()) ||
       !PL_put_float(ref, val) )
    throw PlResourceError();
}

__inline
PlTerm::PlTerm(const PlAtom &a)
{ if ( !(ref = PL_new_term_ref()) )
    throw PlResourceError();

  PL_put_atom(ref, a.handle);
}

__inline
PlTerm::PlTerm(void *ptr)
{ if ( !(ref = PL_new_term_ref()) ||
       !PL_put_pointer(ref, ptr) )
    throw PlResourceError();
}

		 /*******************************
		 *  SPECIALISED IMPLEMENTATIONS *
		 *******************************/

__inline
PlString::PlString(const char *text) : PlTerm()
{ if ( !PL_put_string_chars(ref, text) )
    throw PlResourceError();
}

__inline
PlString::PlString(const char *text, size_t len) : PlTerm()
{ if ( !PL_put_string_nchars(ref, len, text) )
    throw PlResourceError();
}

__inline
PlString::PlString(const wchar_t *text) : PlTerm()
{ if ( !PL_unify_wchars(ref, PL_STRING, (size_t)-1, text) )
    throw PlResourceError();
}

__inline
PlString::PlString(const wchar_t *text, size_t len) : PlTerm()
{ if ( !PL_unify_wchars(ref, PL_STRING, len, text) )
    throw PlResourceError();
}

__inline
PlCodeList::PlCodeList(const char *text) : PlTerm()
{ if ( !PL_put_list_codes(ref, text) )
    throw PlResourceError();
}

__inline
PlCharList::PlCharList(const char *text) : PlTerm()
{ if ( !PL_put_list_chars(ref, text) )
    throw PlResourceError();
}

__inline
PlCodeList::PlCodeList(const wchar_t *text) : PlTerm()
{ if ( !PL_unify_wchars(ref, PL_CODE_LIST, (size_t)-1, text) )
    throw PlResourceError();
}

__inline
PlCharList::PlCharList(const wchar_t *text) : PlTerm()
{ if ( !PL_unify_wchars(ref, PL_CHAR_LIST, (size_t)-1, text) )
    throw PlResourceError();
}


		 /*******************************
		 *             LISTS		*
		 *******************************/

class PlTail : public PlTerm
{
public:

  PlTail(const PlTerm &l)
  { if ( PL_is_variable(l.ref) || PL_is_list(l.ref) )
    { if ( !(ref = PL_copy_term_ref(l.ref)) )
	throw PlResourceError();
    } else
      throw PlTypeError("list", l.ref);
  }

					/* building */
  int append(const PlTerm &e)
  { term_t tmp, ex;

    if ( (tmp = PL_new_term_ref()) &&
	 PL_unify_list(ref, tmp, ref) &&
	 PL_unify(tmp, e.ref) )
    { PL_reset_term_refs(tmp);
      return TRUE;
    }

    if ( (ex = PL_exception(0)) )
      throw PlResourceError(ex);

    return FALSE;
  }
  int close()
  { return PL_unify_nil(ref);
  }

					/* enumerating */
  int next(PlTerm &t)
  { if ( PL_get_list(ref, t, ref) )
      return TRUE;

    if ( PL_get_nil(ref) )
      return FALSE;

    throw PlTypeError("list", ref);
  }
};


		 /*******************************
		 *	     REGISTER		*
		 *******************************/


class PlRegister
{
public:

  PlRegister(const char *module, const char *name, int arity,
	    foreign_t (f)(term_t t0, int a, control_t ctx))
  { PL_register_foreign_in_module(module, name, arity, reinterpret_cast<pl_function_t>(f), PL_FA_VARARGS);
  }

  PlRegister(const char *module, const char *name, foreign_t (*f)(PlTerm a0))
  { PL_register_foreign_in_module(module, name, 1, reinterpret_cast<pl_function_t>(f), 0);
  }
  PlRegister(const char *module, const char *name, foreign_t (*f)(PlTerm a0, PlTerm a1))
  { PL_register_foreign_in_module(module, name, 2, reinterpret_cast<pl_function_t>(f), 0);
  }
  PlRegister(const char *module, const char *name, foreign_t (*f)(PlTerm a0, PlTerm a1, PlTerm a2))
  { PL_register_foreign_in_module(module, name, 3, reinterpret_cast<pl_function_t>(f), 0);
  }

  // for non-deterministic calls
  PlRegister(const char *module, const char *name, int arity,
             foreign_t (f)(term_t t0, int a, control_t ctx), short flags)
  { PL_register_foreign_in_module(module, name, arity, reinterpret_cast<pl_function_t>(f), flags);
  }
};


		 /*******************************
		 *	 CALLING PROLOG		*
		 *******************************/

class PlFrame
{
public:
  fid_t fid;

  PlFrame()
  { fid = PL_open_foreign_frame();
  }

  ~PlFrame()
  { PL_close_foreign_frame(fid);
  }

  void rewind()
  { PL_rewind_foreign_frame(fid);
  }
};


class PlQuery
{
public:
  qid_t qid;

  PlQuery(predicate_t pred, const PlTermv &av)
  { qid = PL_open_query((module_t)0, PL_Q_PASS_EXCEPTION, pred, av.a0);
    if ( !qid )
      throw PlResourceError();
  }
  PlQuery(const char *name, const PlTermv &av)
  { predicate_t p = PL_predicate(name, av.size, "user");

    qid = PL_open_query((module_t)0, PL_Q_PASS_EXCEPTION, p, av.a0);
    if ( !qid )
      throw PlResourceError();
  }
  PlQuery(const char *module, const char *name, const PlTermv &av)
  { atom_t ma = PL_new_atom(module);
    atom_t na = PL_new_atom(name);
    module_t m = PL_new_module(ma);
    predicate_t p = PL_pred(PL_new_functor(na, av.size), m);

    PL_unregister_atom(ma);
    PL_unregister_atom(na);

    qid = PL_open_query(m, PL_Q_PASS_EXCEPTION, p, av.a0);
    if ( !qid )
      throw PlResourceError();
  }

  ~PlQuery()
  { if ( qid )
      PL_cut_query(qid);
  }

  int next_solution();
};


__inline int
PlCall(const char *predicate, const PlTermv &args)
{ PlQuery q(predicate, args);
  return q.next_solution();
}

__inline int
PlCall(const char *module, const char *predicate, const PlTermv &args)
{ PlQuery q(module, predicate, args);
  return q.next_solution();
}

__inline int
PlCall(const char *goal)
{ PlQuery q("call", PlTermv(PlCompound(goal)));
  return q.next_solution();
}

__inline int
PlCall(const wchar_t *goal)
{ PlQuery q("call", PlTermv(PlCompound(goal)));
  return q.next_solution();
}


		 /*******************************
		 *	    ATOM (BODY)		*
		 *******************************/

__inline
PlAtom::PlAtom(const PlTerm &t)
{ atom_t a;

  if ( PL_get_atom(t.ref, &a) )
    handle = a;
  else
    throw PlTypeError("atom", t);
}


		 /*******************************
		 *	    TERM (BODY)		*
		 *******************************/

					/* PlTerm --> C */

__inline PlTerm::operator char *(void) const
{ char *s;

  if ( PL_get_chars(ref, &s, CVT_ALL|CVT_WRITEQ|BUF_RING) )
    return s;

  throw PlTypeError("text", ref);
}

__inline PlTerm::operator wchar_t *(void) const
{ wchar_t *s;

  if ( PL_get_wchars(ref, NULL, &s, CVT_ALL|CVT_WRITEQ|BUF_RING) )
    return s;

  throw PlTypeError("text", ref);
}

__inline PlTerm::operator long(void) const
{ long v;

  if ( PL_get_long(ref, &v) )
    return v;

  throw PlTypeError("integer", ref);
}

__inline PlTerm::operator int(void) const
{ int v;

  if ( PL_get_integer(ref, &v) )
    return v;

  throw PlTypeError("integer", ref);
}

__inline PlTerm::operator double(void) const
{ double v;

  if ( PL_get_float(ref, &v) )
    return v;

  throw PlTypeError("float", ref);
}

__inline PlTerm::operator PlAtom(void) const
{ atom_t v;

  if ( PL_get_atom(ref, &v) )
    return PlAtom(v);

  throw PlTypeError("atom", ref);
}

__inline PlTerm::operator void *(void) const
{ void *ptr;

  if ( PL_get_pointer(ref, &ptr) )
    return ptr;

  throw PlTypeError("pointer", ref);
}

					/* compounds */

__inline PlTerm
PlTerm::operator [](ARITY_T index) const
{ PlTerm t;

  if ( PL_get_arg(index, ref, t.ref) )
    return t;

  if ( !PL_is_compound(ref) )
    throw PlTypeError("compound", ref);
  else
  { if ( !PL_put_integer(t.ref, index) )
      throw PlResourceError();

    if ( index < 1 )
      throw PlDomainError("not_less_than_zero", t.ref);
    else
      throw PlDomainError("arity", t.ref); /* TBD: proper exception */
  }
}


__inline ARITY_T
PlTerm::arity() const
{ atom_t name;
  ARITY_T arity;

  if ( PL_get_name_arity(ref, &name, &arity) )
    return arity;

  throw PlTypeError("compound", ref);
}


__inline const char *
PlTerm::name() const
{ atom_t name;
  ARITY_T arity;

  if ( PL_get_name_arity(ref, &name, &arity) )
    return PL_atom_chars(name);

  throw PlTypeError("compound", ref);
}


					/* Unification */

__inline int PlTerm::operator =(const PlTerm &t2)	/* term = term */
{ int rc = PL_unify(ref, t2.ref);
  term_t ex;

  if ( !rc && (ex=PL_exception(0)) )
    throw PlResourceError(ex);
  return rc;
}

__inline int PlTerm::operator =(const PlAtom &a)	/* term = atom */
{ int rc = PL_unify_atom(ref, a.handle);
  term_t ex;

  if ( !rc && (ex=PL_exception(0)) )
    throw PlResourceError(ex);
  return rc;
}

__inline int PlTerm::operator =(const char *v)		/* term = atom */
{ int rc = PL_unify_atom_chars(ref, v);
  term_t ex;

  if ( !rc && (ex=PL_exception(0)) )
    throw PlResourceError(ex);
  return rc;
}

__inline int PlTerm::operator =(const wchar_t *v)	/* term = atom */
{ int rc = PL_unify_wchars(ref, PL_ATOM, (size_t)-1, v);
  term_t ex;

  if ( !rc && (ex=PL_exception(0)) )
    throw PlResourceError(ex);
  return rc;
}

__inline int PlTerm::operator =(long v)
{ int rc = PL_unify_integer(ref, v);
  term_t ex;

  if ( !rc && (ex=PL_exception(0)) )
    throw PlResourceError(ex);
  return rc;
}

__inline int PlTerm::operator =(int v)
{ int rc = PL_unify_integer(ref, v);
  term_t ex;

  if ( !rc && (ex=PL_exception(0)) )
    throw PlResourceError(ex);
  return rc;
}

__inline int PlTerm::operator =(double v)
{ int rc = PL_unify_float(ref, v);
  term_t ex;

  if ( !rc && (ex=PL_exception(0)) )
    throw PlResourceError(ex);
  return rc;
}

__inline int PlTerm::operator =(const PlFunctor &f)
{ int rc = PL_unify_functor(ref, f.functor);
  term_t ex;

  if ( !rc && (ex=PL_exception(0)) )
    throw PlResourceError(ex);
  return rc;
}

					/* comparison */


__inline int PlTerm::operator ==(long v) const
{ long v0;

  if ( PL_get_long(ref, &v0) )
    return v0 == v;

  throw PlTypeError("integer", ref);
}

__inline int PlTerm::operator !=(long v) const
{ long v0;

  if ( PL_get_long(ref, &v0) )
    return v0 != v;

  throw PlTypeError("integer", ref);
}

__inline int PlTerm::operator <(long v) const
{ long v0;

  if ( PL_get_long(ref, &v0) )
    return v0 < v;

  throw PlTypeError("integer", ref);
}

__inline int PlTerm::operator >(long v) const
{ long v0;

  if ( PL_get_long(ref, &v0) )
    return v0 > v;

  throw PlTypeError("integer", ref);
}

__inline int PlTerm::operator <=(long v) const
{ long v0;

  if ( PL_get_long(ref, &v0) )
    return v0 <= v;

  throw PlTypeError("integer", ref);
}

__inline int PlTerm::operator >=(long v) const
{ long v0;

  if ( PL_get_long(ref, &v0) )
    return v0 >= v;

  throw PlTypeError("integer", ref);
}

				      /* comparison (string) */

__inline int PlTerm::operator ==(const char *s) const
{ char *s0;

  if ( PL_get_chars(ref, &s0, CVT_ALL) )
    return strcmp(s0, s) == 0;

  throw PlTypeError("text", ref);
}

__inline int PlTerm::operator ==(const wchar_t *s) const
{ wchar_t *s0;

  if ( PL_get_wchars(ref, NULL, &s0, CVT_ALL) )
    return wcscmp(s0, s) == 0;

  throw PlTypeError("text", ref);
}

__inline int PlTerm::operator ==(const PlAtom &a) const
{ atom_t v;

  if ( PL_get_atom(ref, &v) )
    return v == a.handle;

  throw PlTypeError("atom", ref);
}


		 /*******************************
		 *	   COMPOUND (BODY)	*
		 *******************************/

__inline void
PlPutTerm(term_t to, term_t from)
{ if ( !PL_put_term(to, from) )
    throw PlResourceError();
}


__inline
PlCompound::PlCompound(const char *text) : PlTerm()
{ term_t t = PL_new_term_ref();

  if ( !PL_chars_to_term(text, t) )
    throw PlException(t);

  PlPutTerm(ref, t);
}

__inline
PlCompound::PlCompound(const wchar_t *text) : PlTerm()
{ term_t t = PL_new_term_ref();

  if ( !PL_wchars_to_term(text, t) )
    throw PlException(t);

  PlPutTerm(ref, t);
}

__inline
PlCompound::PlCompound(const char *functor, const PlTermv &args) : PlTerm()
{ if ( !PL_cons_functor_v(ref,
			  PL_new_functor(PL_new_atom(functor), args.size),
			  args.a0) )
    throw PlResourceError();
}

__inline
PlCompound::PlCompound(const wchar_t *functor, const PlTermv &args) : PlTerm()
{ if ( !PL_cons_functor_v(
	    ref,
	    PL_new_functor(PL_new_atom_wchars(wcslen(functor), functor),
			   args.size),
	    args.a0) )
    throw PlResourceError();
}

		 /*******************************
		 *	   TERMV (BODY)		*
		 *******************************/


__inline PlTermv::PlTermv(PlTerm m0)
{ size = 1;
  a0 = m0.ref;
}

__inline PlTermv::PlTermv(PlTerm m0, PlTerm m1)
{ size = 2;
  if ( !(a0 = PL_new_term_refs(2)) )
    throw PlResourceError();
  PlPutTerm(a0+0, m0);
  PlPutTerm(a0+1, m1);
}

__inline PlTermv::PlTermv(PlTerm m0, PlTerm m1, PlTerm m2)
{ size = 3;
  if ( !(a0 = PL_new_term_refs(3)) )
    throw PlResourceError();
  PlPutTerm(a0+0, m0);
  PlPutTerm(a0+1, m1);
  PlPutTerm(a0+2, m2);
}

__inline PlTermv::PlTermv(PlTerm m0, PlTerm m1, PlTerm m2, PlTerm m3)
{ size = 4;
  if ( !(a0 = PL_new_term_refs(4)) )
    throw PlResourceError();
  PlPutTerm(a0+0, m0);
  PlPutTerm(a0+1, m1);
  PlPutTerm(a0+2, m2);

  PlPutTerm(a0+3, m3);
}

__inline PlTermv::PlTermv(PlTerm m0, PlTerm m1, PlTerm m2,
			  PlTerm m3, PlTerm m4)
{ size = 5;
  if ( !(a0 = PL_new_term_refs(5)) )
    throw PlResourceError();
  PlPutTerm(a0+0, m0);
  PlPutTerm(a0+1, m1);
  PlPutTerm(a0+2, m2);
  PlPutTerm(a0+3, m3);
  PlPutTerm(a0+4, m4);
}


__inline PlTerm
PlTermv::operator [](int n) const
{ if ( n < 0 || n >= size )
    throw PlTermvDomainError(size, n);

  return PlTerm(a0+n);
}


		 /*******************************
		 *	EXCEPTIONS (BODY)       *
		 *******************************/

__inline PlException::operator const char *(void)
{ PlFrame fr;
#ifdef USE_PRINT_MESSAGE
  PlTermv av(2);

  av[0] = PlCompound("print_message",
		     PlTermv("error", ref));
  PlQuery q("$write_on_string", av);
  if ( q.next_solution() )
    return (char *)av[1];
#else
  PlTermv av(2);
  av[0] = PlTerm(ref);
  PlQuery q("$messages", "message_to_string", av);
  if ( q.next_solution() )
    return (char *)av[1];
#endif
  return "[ERROR: Failed to generate message.  Internal error]\n";
}


__inline PlException::operator const wchar_t *(void)
{ PlFrame fr;
#ifdef USE_PRINT_MESSAGE
  PlTermv av(2);

  av[0] = PlCompound("print_message",
		     PlTermv("error", ref));
  PlQuery q("$write_on_string", av);
  if ( q.next_solution() )
    return (wchar_t *)av[1];
#else
  PlTermv av(2);
  av[0] = PlTerm(ref);
  PlQuery q("$messages", "message_to_string", av);
  if ( q.next_solution() )
    return (wchar_t *)av[1];
#endif
  return L"[ERROR: Failed to generate message.  Internal error]\n";
}


__inline void
PlException::cppThrow()
{ term_t a = PL_new_term_ref();
  atom_t name;
  ARITY_T arity;

  if ( PL_get_arg(1, ref, a) &&
       PL_get_name_arity(a, &name, &arity) )
  { const char *s = PL_atom_chars(name);

    if ( strcmp(s, "type_error") == 0 )
      throw PlTypeError(ref);
    if ( strcmp(s, "domain_error") == 0 )
      throw PlDomainError(ref);
    if ( strcmp(s, "resource_error") == 0 )
      throw PlResourceError(ref);
  }

  throw *this;
}


		 /*******************************
		 *	    QUERY (BODY)	*
		 *******************************/

__inline int
PlQuery::next_solution()
{ int rval;

  if ( !(rval = PL_next_solution(qid)) )
  { term_t ex;

    PL_close_query(qid);
    qid = 0;

    if ( (ex = PL_exception(0)) )
      PlException(ex).cppThrow();
  }
  return rval;
}


		 /*******************************
		 *	      ENGINE		*
		 *******************************/

class PlError
{
public:
  char *message;

  PlError(const char *msg)
  { size_t len = strlen(msg)+1;
    message = new char[len];
#ifdef _MSC_VER				/* Yek */
#pragma warning( push )
#pragma warning (disable:4996)
#endif
    strncpy(message, msg, len);
#ifdef _MSC_VER
#pragma warning( pop )
#endif
  }

  ~PlError()
  {
    delete[] message;
  }
};


class PlEngine
{
public:

  PlEngine(int argc, char **argv)
  { if ( !PL_initialise(argc, argv) )
      throw PlError("failed to initialise");
  }

  PlEngine(char *av0)
  { int ac = 0;
    char **av = (char **)malloc(sizeof(char *) * 2);

    av[ac++] = av0;

    if ( !PL_initialise(1, av) )
      throw PlError("failed to initialise");
  }

  ~PlEngine()
  { PL_cleanup(0);
  }
};


		 /*******************************
		 *     REGISTER PREDICATES	*
		 *******************************/

#ifndef PROLOG_MODULE
#define PROLOG_MODULE (const char*)NULL
#endif

#define NAMED_PREDICATE(plname, name, arity) \
	static foreign_t \
	pl_ ## name ## __ ## arity(PlTermv PL_av); \
	static foreign_t \
	_pl_ ## name ## __ ## arity(term_t t0, int a, control_t c) \
	{ (void)a; (void)c; \
          try \
	  { \
	    return pl_ ## name ## __ ## arity(PlTermv(arity, t0)); \
	  } catch ( PlException &ex ) \
	  { return ex.plThrow(); \
	  } \
	} \
	static PlRegister _x ## name ## __ ## arity(PROLOG_MODULE, plname, arity, \
					    _pl_ ## name ## __ ## arity); \
	static foreign_t pl_ ## name ## __ ## arity(PlTermv PL_av)

#define NAMED_PREDICATE0(plname, name) \
	static foreign_t \
	pl_ ## name ## __0(void); \
	static foreign_t \
	_pl_ ## name ## __0(term_t t0, int a, control_t c) \
	{ (void)t0; (void)a; (void)c; \
          try \
	  { \
	    return pl_ ## name ## __0(); \
	  } catch ( PlException &ex ) \
	  { return ex.plThrow(); \
	  } \
	} \
	static PlRegister _x ## name ## __0(PROLOG_MODULE, plname, 0, \
					    _pl_ ## name ## __0); \
	static foreign_t pl_ ## name ## __0(void)

#define NAMED_PREDICATE_NONDET(plname, name, arity)          \
	static foreign_t \
	pl_ ## name ## __ ## arity(PlTermv PL_av, control_t handle);       \
	static foreign_t \
	_pl_ ## name ## __ ## arity(term_t t0, int a, control_t c) \
	{ (void)a; \
          try \
	  { \
	    return pl_ ## name ## __ ## arity(PlTermv(arity, t0), c); \
	  } catch ( PlException &ex ) \
	  { return ex.plThrow(); \
	  } \
	} \
        static PlRegister _x ## name ## __ ## arity(PROLOG_MODULE, plname, arity, \
                                                    _pl_ ## name ## __ ## arity, \
                                                    PL_FA_NONDETERMINISTIC | PL_FA_VARARGS); \
	static foreign_t pl_ ## name ## __ ## arity(PlTermv PL_av, control_t handle)

#define PREDICATE0(name)              NAMED_PREDICATE0(#name, name)
#define PREDICATE(name, arity)        NAMED_PREDICATE(#name, name, arity)
#define PREDICATE_NONDET(name, arity) NAMED_PREDICATE_NONDET(#name, name, arity)

#define PL_A1  PL_av[0]
#define PL_A2  PL_av[1]
#define PL_A3  PL_av[2]
#define PL_A4  PL_av[3]
#define PL_A5  PL_av[4]
#define PL_A6  PL_av[5]
#define PL_A7  PL_av[6]
#define PL_A8  PL_av[7]
#define PL_A9  PL_av[8]
#define PL_A10 PL_av[9]

#ifndef PL_SAFE_ARG_MACROS
#define A1	PL_A1
#define A2	PL_A2
#define A3	PL_A3
#define A4	PL_A4
#define A5	PL_A5
#define A6	PL_A6
#define A7	PL_A7
#define A8	PL_A8
#define A9	PL_A9
#define A10	PL_A10
#endif

#endif /*_SWI_CPP_H*/