attvar.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
 
#ifndef ATTVAR_H
 
#define ATTVAR_H 1
 
#include <TermExt.h>
 
/*
  attvar_entry is just a Prolog structure such that the first argument is
  a pointer to the next args
*/
 
typedef struct attvar_struct {
    Functor AttFunc;      /* functor for attvar */
    Term Done;            /* if unbound suspension active, if bound terminated */
    Term Future;           /* value the variable will take */
    Term Atts; /* actual data */
} attvar_record;
 
#define ATT_RECORD_ARITY  3
 
 #define MAX_EMPTY_WAKEUPS 16
 
/*
  attvar_entry is just a Prolog structure such that the first argument is
  a pointer to the next args
*/
 
 
INLINE_ONLY bool IsAttachFunc(Functor);
 
INLINE_ONLY bool IsAttachFunc(Functor f) { return (Int)(FALSE); }
 
#define IsAttachedTerm(t) __IsAttachedTerm(t PASS_REGS)
 
INLINE_ONLY bool __IsAttachedTerm(Term USES_REGS);
 
INLINE_ONLY bool __IsAttachedTerm(Term t USES_REGS) {
    return (IsVarTerm(t) &&
            IsAttVar(VarOfTerm(t)));
}
 
INLINE_ONLY bool GlobalIsAttachedTerm(Term);
 
INLINE_ONLY bool GlobalIsAttachedTerm(Term t) {
    return (IsVarTerm(t) &&
            GlobalIsAttVar(VarOfTerm(t)));
}
 
#define SafeIsAttachedTerm(t) __SafeIsAttachedTerm((t)PASS_REGS)
 
INLINE_ONLY bool __SafeIsAttachedTerm(Term USES_REGS);
 
INLINE_ONLY bool __SafeIsAttachedTerm(Term t USES_REGS) {
    return IsVarTerm(t) && IsAttVar(VarOfTerm(t));
}
 
static inline Term
AbsAttVar(attvar_record *attvar_ptr) {
  return attvar_ptr->Done;
}
 
static inline attvar_record *
RepAttVar(Term *var_ptr) {
  return (attvar_record *)(var_ptr-1);
}
 
extern void AddToQueue(attvar_record *attv USES_REGS);
 
#define TermVoidAtt TermFoundVar
 
#endif