YapCompoundTerm.h

/*************************************************************************
 *                                   *
 *   YAP Prolog     %W% %G%                      *
 *  Yap Prolog was developed at NCCUP - Universidade do Porto    *
 *                                   *
 * Copyright L.Damas, V.S.Costa and Universidade do Porto 1985-2012  *
 *                                   *
 **************************************************************************
 *                                   *
 * File:        YapCompounTerm.h *
 * mods: *
 * comments:    main header file for YAP                 *
 * version:      $Id: Yap.h,v 1.38 2008-06-18 10:02:27 vsc Exp $     *
 *************************************************************************/
 
/*************************************************************************************************
                           High level macros to access arguments
*************************************************************************************************/
 
#ifndef YAPCOMPOUNDTERM_H
 
#define YAPCOMPOUNDTERM_H 1
 
#include "inline-only.h"
 
EXTERN bool Yap_unify(Term a, Term b);
 
INLINE_ONLY Term Deref(Term a);
 
INLINE_ONLY Term Deref(Term a) {
  while (IsVarTerm(a)) {
    Term *b = (Term *)a;
 
 
    a = *b;
    if (a == ((Term)b))
      return a;
  }
  return (a);
}
 
INLINE_ONLY CELL *GetTermAdress(Term a);
 
 
INLINE_ONLY Term Derefa(CELL *b) {
  Term a = *b;
restart:
  if (!IsVarTerm(a)) {
    return (a);
  } else if (a == (CELL)b) {
    return (a);
  } else {
    b = (CELL *)a;
    a = *b;
    goto restart;
  }
}
 
INLINE_ONLY Term ArgOfTerm(int i, Term t);
 
INLINE_ONLY Term ArgOfTerm(int i, Term t)
 
{
  return (Term)(Derefa(RepAppl(t) + (i)));
}
 
INLINE_ONLY Term HeadOfTerm(Term);
 
INLINE_ONLY Term HeadOfTerm(Term t) {
  return (Term)(Derefa(RepPair(t)));
}
 
INLINE_ONLY Term TailOfTerm(Term);
 
INLINE_ONLY Term TailOfTerm(Term t) {
  return (Term)(Derefa(RepPair(t) + 1));
}
 
INLINE_ONLY Term ArgOfTermCell(int i, Term t);
 
INLINE_ONLY Term ArgOfTermCell(int i, Term t) {
  return (Term)((CELL)(RepAppl(t) + (i)));
}
 
INLINE_ONLY Term HeadOfTermCell(Term);
 
INLINE_ONLY Term HeadOfTermCell(Term t) {
  return (Term)((CELL)(RepPair(t)));
}
 
INLINE_ONLY Term TailOfTermCell(Term);
 
INLINE_ONLY Term TailOfTermCell(Term t) {
  return (Term)((CELL)(RepPair(t) + 1));
}
 
#endif /* YAPCOMPOUNDTERM_H */