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