yap-6.3/H/corout.h

/*************************************************************************
*									 *
*	 YAP Prolog 							 *
*									 *
*	Yap Prolog was developed at NCCUP - Universidade do Porto	 *
*									 *
* Copyright L.Damas, V.S.Costa and Universidade do Porto 1985-1997	 *
*									 *
**************************************************************************
*									 *
* File:		corout.c						 *
* Last rev:								 *
* mods:									 *
* comments:	Co-routining from within YAP				 *
*									 *
*************************************************************************/
#ifdef SCCS
static char SccsId[]="%W% %G%";
#endif

typedef struct sus_record_struct {
  Functor f;
  Term NR;		/* next record for same variable */
  Term SG;		/* actual suspended goal */
  Term NS;	        /* other suspended goals */
} sus_record;

typedef struct sus_tag_struct {
  Term	ActiveSus;		/* if unbound suspension active, if bound terminated   */
  CELL sus_id;
  Term TimeStamp;	/* actual suspended goal */
  Term SG;		/* list of suspended goals */
} sus_tag;

#ifdef COROUTINING
/*********** tags for suspension variables */
#define AbsSuspendedVar(sustag_ptr)	AbsAppl(((CELL *)(sustag_ptr)))
#define RepSuspendedVar(val)		((sus_tag *)RepAppl(val))
#endif