/*************************************************************************
*									 *
*	 YAP Prolog   %W% %G%
*									 *
*	Yap Prolog was developed at NCCUP - Universidade do Porto	 *
*									 *
* Copyright L.Damas, V.S.Costa and Universidade do Porto 1985-1997	 *
*									 *
**************************************************************************
*									 *
* File:		Atoms.h.m4						 *
* Last rev:	19/2/88							 *
* mods:									 *
* comments:	atom properties header file for YAP			 *
*									 *
*************************************************************************/

#undef EXTERN
#ifndef ADTDEFS_C
#define EXTERN  static
#else
#define EXTERN
#endif

/*********  operations for atoms ****************************************/

/*    Atoms are assumed to be uniquely represented by an OFFSET and to have
    associated with them a struct of type AtomEntry
    The	two functions
	RepAtom	: Atom -> *AtomEntry
	AbsAtom	: *AtomEntry ->	Atom
    are used to encapsulate the implementation of atoms
*/

typedef struct AtomEntryStruct *Atom;
typedef struct PropEntryStruct *Prop;


/* I can only define the structure after I define the actual atoms */

/*		 atom structure						*/
typedef struct AtomEntryStruct {
  Atom            NextOfAE;	/* used	to build hash chains			*/
  Prop            PropsOfAE;	/* property list for this atom			*/
#if defined(YAPOR) || defined(THREADS)
  rwlock_t        ARWLock;
#endif
  
  char            StrOfAE[MIN_ARRAY];	/* representation of atom as a string		*/
}
AtomEntry;

/* Props and Atoms are stored in chains, ending with a NIL */
#if USE_OFFSETS
#	define EndOfPAEntr(P)	( Addr(P) == AtomBase)
#else
#	define EndOfPAEntr(P)	( Addr(P) == NIL )
#endif

#define AtomName(at)	RepAtom(at)->StrOfAE


/* ********************** Properties  **********************************/

#if USE_OFFSETS
#define USE_OFFSETS_IN_PROPS 1
#else
#define USE_OFFSETS_IN_PROPS 0
#endif

typedef SFLAGS PropFlags;

/*	    basic property entry structure				*/
typedef	struct PropEntryStruct {
    Prop    NextOfPE;	/* used	to chain properties			*/
    PropFlags    KindOfPE;	/* kind	of property				*/
    } PropEntry;

/* ************************* Functors  **********************************/

     /*		Functor	data type
      abstype Functor =	atom # int
      with MkFunctor(a,n) = ...
      and  NameOfFunctor(f) = ...
      and  ArityOfFunctor(f) = ...					*/

#define	MaxArity	    255


#define FunctorProperty   ((PropFlags)(0xbb00))

/* functor property */
typedef struct FunctorEntryStruct {
    Prop	NextOfPE;	/* used	to chain properties	*/
    PropFlags	KindOfPE;	/* kind	of property		*/
    unsigned int ArityOfFE;	/* arity of functor		*/
    Atom	NameOfFE;       /* back pointer to owner atom   */
    Prop	PropsOfFE;      /* pointer to list of properties for this functor */
#if defined(YAPOR) || defined(THREADS)
    rwlock_t        FRWLock;
#endif
} FunctorEntry;

typedef FunctorEntry *Functor;

