agenda.c

clips源代码

   SaveCurrentModule(theEnv);

   /*=============================================*/
   /* If the module specified is a NULL pointer,  */
   /* then every module has its agenda refreshed. */
   /*=============================================*/

   if (theModule == NULL)
     {
      allModules = TRUE;
      theModule = (struct defmodule *) EnvGetNextDefmodule(theEnv,NULL);
     }

   /*=======================================================*/
   /* Remember the current setting for salience evaluation. */
   /* To perform the refresh, the when activated setting is */
   /* used to recompute the salience values.                */
   /*=======================================================*/

   oldValue = EnvGetSalienceEvaluation(theEnv);
   EnvSetSalienceEvaluation(theEnv,WHEN_ACTIVATED);

   /*========================*/
   /* Refresh the agenda(s). */
   /*========================*/

   for (;
        theModule != NULL;
        theModule = (struct defmodule *) EnvGetNextDefmodule(theEnv,theModule))
     {
      /*=========================================*/
      /* Change the current module to the module */
      /* of the agenda being refreshed.          */
      /*=========================================*/

      EnvSetCurrentModule(theEnv,(void *) theModule);

      /*================================================================*/
      /* Recompute the salience values for the current module's agenda. */
      /*================================================================*/

      for (theActivation = (struct activation *) EnvGetNextActivation(theEnv,NULL);
           theActivation != NULL;
           theActivation = (struct activation *) EnvGetNextActivation(theEnv,theActivation))
        { theActivation->salience = EvaluateSalience(theEnv,theActivation->theRule); }

      /*======================================================*/
      /* Reorder the agenda based on the new salience values. */
      /*======================================================*/

      EnvReorderAgenda(theEnv,theModule);

      /*===============================================*/
      /* Return if only one agenda is being refreshed. */
      /*===============================================*/

      if (! allModules)
        {
         EnvSetSalienceEvaluation(theEnv,oldValue);
         RestoreCurrentModule(theEnv);
         return;
        }
     }

   /*==========================================*/
   /* Restore the salience evaluation setting. */
   /*==========================================*/

   EnvSetSalienceEvaluation(theEnv,oldValue);

   /*=============================*/
   /* Restore the current module. */
   /*=============================*/

   RestoreCurrentModule(theEnv);
  }

/*********************************************************/
/* SetSalienceEvaluationCommand: H/L Command for setting */
/*   the salience evaluation behavior.                   */
/*   Syntax: (set-salience-evaluation-behavior <symbol>) */
/*********************************************************/
globle void *SetSalienceEvaluationCommand(
  void *theEnv)
  {
   DATA_OBJECT argPtr;
   char *argument, *oldValue;

   /*==================================================*/
   /* Get the current setting for salience evaluation. */
   /*==================================================*/

   oldValue = SalienceEvaluationName(EnvGetSalienceEvaluation(theEnv));

   /*=========================================*/
   /* This function expects a single argument */
   /* which must be a symbol.                 */
   /*=========================================*/

   if (EnvArgCountCheck(theEnv,"set-salience-evaluation",EXACTLY,1) == -1)
     { return((SYMBOL_HN *) EnvAddSymbol(theEnv,oldValue)); }

   if (EnvArgTypeCheck(theEnv,"set-salience-evaluation",1,SYMBOL,&argPtr) == FALSE)
     { return((SYMBOL_HN *) EnvAddSymbol(theEnv,oldValue)); }

   /*=============================================================*/
   /* The allowed symbols to pass as an argument to this function */
   /* are when-defined, when-activated, and every-cycle.          */
   /*=============================================================*/

   argument = DOToString(argPtr);

   if (strcmp(argument,"when-defined") == 0)
     { EnvSetSalienceEvaluation(theEnv,WHEN_DEFINED); }
   else if (strcmp(argument,"when-activated") == 0)
     { EnvSetSalienceEvaluation(theEnv,WHEN_ACTIVATED); }
   else if (strcmp(argument,"every-cycle") == 0)
     { EnvSetSalienceEvaluation(theEnv,EVERY_CYCLE); }
   else
     {
      ExpectedTypeError1(theEnv,"set-salience-evaluation",1,
      "symbol with value when-defined, when-activated, or every-cycle");
      return((SYMBOL_HN *) EnvAddSymbol(theEnv,oldValue));
     }

   /*=================================================*/
   /* Return the old setting for salience evaluation. */
   /*=================================================*/

   return((SYMBOL_HN *) EnvAddSymbol(theEnv,oldValue));
  }

/*********************************************************/
/* GetSalienceEvaluationCommand: H/L Command for getting */
/*   the salience evaluation behavior.                   */
/*   Syntax: (get-salience-evaluation-behavior)          */
/*********************************************************/
globle void *GetSalienceEvaluationCommand(
  void *theEnv)
  {
   EnvArgCountCheck(theEnv,"get-salience-evaluation",EXACTLY,0);

   return((SYMBOL_HN *) EnvAddSymbol(theEnv,SalienceEvaluationName(EnvGetSalienceEvaluation(theEnv))));
  }

/*****************************************************************/
/* SalienceEvaluationName: Given the integer value corresponding */
/*   to a specified salience evaluation behavior, returns a      */
/*   character string of the behavior's name.                    */
/*****************************************************************/
static char *SalienceEvaluationName(
  int strategy)
  {
   char *sname;

   switch (strategy)
     {
      case WHEN_DEFINED:
        sname = "when-defined";
        break;
      case WHEN_ACTIVATED:
        sname = "when-activated";
        break;
      case EVERY_CYCLE:
        sname = "every-cycle";
        break;
      default:
        sname = "unknown";
        break;
     }

   return(sname);
  }

/****************************************************************/
/* EnvGetSalienceEvaluation: Returns the value of current type  */
/*  of salience evaluation (e.g., when defined, when activated, */
/*  or every cycle).                                            */
/****************************************************************/
globle intBool EnvGetSalienceEvaluation(
  void *theEnv)
  {   
   return(AgendaData(theEnv)->SalienceEvaluation); 
  }

/***********************************************/
/* EnvSetSalienceEvaluation: Sets the value of */
/*   the current type of salience evaluation.  */
/***********************************************/
globle intBool EnvSetSalienceEvaluation(
  void *theEnv,
  int value)
  {
   int ov;

   ov = AgendaData(theEnv)->SalienceEvaluation;
   AgendaData(theEnv)->SalienceEvaluation = value;
   return(ov);
  }

/*****************************************************************/
/* EvaluateSalience: Returns the salience value of the specified */
/*   defrule. If salience evaluation is currently set to         */
/*   when-defined, then the current value of the rule's salience */
/*   is returned. Otherwise the salience expression associated   */
/*   with the rule is reevaluated, the value is stored as the    */
/*   rule's current salience, and it is then returned.           */
/*****************************************************************/
static int EvaluateSalience(
  void *theEnv,
  void *vPtr)
  {
   struct defrule *rPtr = (struct defrule *) vPtr;
   DATA_OBJECT salienceValue;
   int salience;

  /*==================================================*/
  /* If saliences are only being evaluated when rules */
  /* are defined, then just return the last salience  */
  /* value evaluated for the rule.                    */
  /*==================================================*/

  if (EnvGetSalienceEvaluation(theEnv) == WHEN_DEFINED)
    { return(rPtr->salience); }

  /*=================================================================*/
  /* If the rule's salience value was defined as an integer constant */
  /* (i.e., not an expression or global variable which could change  */
  /* on reevaluation), then just return the salience value computed  */
  /* for the rule when it was defined.                               */
  /*=================================================================*/

  if (rPtr->dynamicSalience == NULL) return(rPtr->salience);

  /*====================================================*/
  /* Reevaluate the rule's salience. If an error occurs */
  /* during evaluation, print an error message.         */
  /*====================================================*/

  SetEvaluationError(theEnv,FALSE);
  if (EvaluateExpression(theEnv,rPtr->dynamicSalience,&salienceValue))
    {
     SalienceInformationError(theEnv,"defrule",ValueToString(rPtr->header.name));
     return(rPtr->salience);
    }

  /*========================================*/
  /* The salience value must be an integer. */
  /*========================================*/

  if (salienceValue.type != INTEGER)
    {
     SalienceNonIntegerError(theEnv);
     SalienceInformationError(theEnv,"defrule",ValueToString(rPtr->header.name));
     SetEvaluationError(theEnv,TRUE);
     return(rPtr->salience);
    }

  /*==========================================*/
  /* The salience value must fall between the */
  /* minimum and maximum allowed values.      */
  /*==========================================*/

  salience = (int) ValueToLong(salienceValue.value);

  if ((salience > MAX_DEFRULE_SALIENCE) || (salience < MIN_DEFRULE_SALIENCE))
    {
     SalienceRangeError(theEnv,MIN_DEFRULE_SALIENCE,MAX_DEFRULE_SALIENCE);
     SetEvaluationError(theEnv,TRUE);
     SalienceInformationError(theEnv,"defrule",ValueToString(((struct defrule *) rPtr)->header.name));
     return(rPtr->salience);
    }

  /*===================================*/
  /* Store the new salience value with */
  /* the rule and return this value.   */
  /*===================================*/

  rPtr->salience = salience;
  return(rPtr->salience);
 }

#if DEBUGGING_FUNCTIONS

/***********************************************/
/* AgendaCommand: Prints out the agenda of the */
/*   rules that are ready to fire.             */
/*   Syntax: (agenda)                          */
/***********************************************/
globle void AgendaCommand(
  void *theEnv)
  {
   int numArgs, error;
   struct defmodule *theModule;

   /*==============================================*/
   /* This function can have at most one argument. */
   /*==============================================*/

   if ((numArgs = EnvArgCountCheck(theEnv,"agenda",NO_MORE_THAN,1)) == -1) return;

   /*===============================================================*/
   /* If a module name is specified, then the agenda of that module */
   /* is displayed. Otherwise, the agenda of the current module is  */
   /* displayed.                                                    */
   /*===============================================================*/

   if (numArgs == 1)
     {
      theModule = GetModuleName(theEnv,"agenda",1,&error);
      if (error) return;
     }
   else
     { theModule = ((struct defmodule *) EnvGetCurrentModule(theEnv)); }

   /*===============================================*/
   /* Display the agenda of the appropriate module. */
   /*===============================================*/

   EnvAgenda(theEnv,WDISPLAY,theModule);
  }

#endif /* DEBUGGING_FUNCTIONS */

#endif /* DEFRULE_CONSTRUCT */