#ifndef __CUT_C_H__
#define __CUT_C_H__

/* Some definitions */
#define Choice_Point_Type void *

/* necessary for not redefine NULL*/
#ifndef NULL
#define NULL nil
#endif

typedef struct cut_c_str *cut_c_str_ptr;
struct cut_c_str{
  cut_c_str_ptr before;
  void *try_userc_cut_yamop;
};

#define CUT_C_STR_SIZE ((sizeof(struct cut_c_str))/(sizeof(CELL)))

#define EXTRA_CBACK_CUT_ARG(Type,Offset) \
((Type) (*(Type *)(((CELL *)Yap_REGS.CUT_C_TOP) - (((yamop *)Yap_REGS.CUT_C_TOP->try_userc_cut_yamop)->u.OtapFs.extra)) + (Offset-1)))

#define CUT_C_PUSH(YAMOP,S_YREG)                                 \
           {                                                     \
             if ((YAMOP)->u.OtapFs.f){                              \
	      S_YREG = S_YREG - CUT_C_STR_SIZE;                  \
              cut_c_str_ptr new_top = (cut_c_str_ptr) S_YREG;    \
              new_top->try_userc_cut_yamop = YAMOP;              \
	      cut_c_push(new_top);                               \
	     }                                                   \
           }


#define POP_CHOICE_POINT(cp) \
  (((CELL *)Yap_REGS.CUT_C_TOP != (CELL *)Yap_LocalBase) && ((CELL *)(cp) > (CELL *)Yap_REGS.CUT_C_TOP)) 


#define POP_EXECUTE()                                                                 \
        cut_c_str_ptr TOP = Yap_REGS.CUT_C_TOP;                                            \
        CPredicate func = (CPredicate)((yamop *)TOP->try_userc_cut_yamop)->u.OtapFs.f;   \
        PredEntry *pred = (PredEntry *)((yamop *)TOP->try_userc_cut_yamop)->u.OtapFs.p;  \
	Yap_StartSlots(); \
        YAP_ExecuteOnCut(pred,func);                                                       \
	Yap_CloseSlots(); \
        cut_c_pop();


/*Initializes CUT_C_TOP*/
void cut_c_initialize(void);

/*Removes a choice_point from the stack*/
void cut_c_pop(void);

/*Insert a choice_point in the stack*/
void cut_c_push(cut_c_str_ptr);

#endif /*_CUT_C_H__*/