factgen.c

NASA 开发使用的一个专家系统

   
   ClearBitString(&hack,sizeof(struct factGetVarJN1Call));
   
   /*========================================*/
   /* A slot value of zero indicates that we */
   /* want the pattern address returned.     */
   /*========================================*/
   
   if (theNode->slotNumber <= 0)
     {
      hack.factAddress = 1;
      hack.allFields = 0;
      hack.whichSlot = 0;
      hack.whichField = 0;
     }
     
   /*=====================================================*/
   /* A slot value greater than zero and a field value of */
   /* zero indicate that we want the entire contents of   */
   /* the slot whether it is a single field or multifield */
   /* slot.                                               */
   /*=====================================================*/
   
   else if (theNode->index <= 0)
     {
      hack.factAddress = 0;
      hack.allFields = 1;
      hack.whichSlot = theNode->slotNumber - 1;
      hack.whichField = 0;
     }
     
   /*=====================================================*/
   /* A slot value, m, and a field value, n, both greater */
   /* than zero indicate that we want the nth field of    */
   /* the mth slot.                                       */
   /*=====================================================*/
   
   else
     {
      hack.factAddress = 0;
      hack.allFields = 0;
      hack.whichSlot = theNode->slotNumber - 1;
      hack.whichField = theNode->index - 1;
     }
     
   /*=========================================*/
   /* Store the position in the partial match */
   /* from which the fact will be retrieved.  */
   /*=========================================*/
   
   hack.whichPattern = theNode->pattern - 1;

   /*=============================*/
   /* Return the argument bitmap. */
   /*=============================*/
   
   return(AddBitMap(&hack,sizeof(struct factGetVarJN1Call)));
  }
  
/**************************************************************/
/* FactGetVarJN2: Creates the arguments for the routine which */
/*   retrieves a variable's value from a single field slot of */
/*   a fact. The retrieval relies on information stored in a  */
/*   partial match, so this retrieval mechanism is used by    */
/*   expressions in the join network or from the RHS of a     */
/*   rule.                                                    */ 
/**************************************************************/
static VOID *FactGetVarJN2(theNode)
  struct lhsParseNode *theNode;
  {
   struct factGetVarJN2Call hack;
   
   /*===================================================*/
   /* Clear the bitmap for storing the argument values. */
   /*===================================================*/

   ClearBitString(&hack,sizeof(struct factGetVarJN2Call));
   
   /*=====================================================*/
   /* Store the position in the partial match from which  */
   /* the fact will be retrieved and the slot in the fact */
   /* from which the value will be retrieved.             */
   /*=====================================================*/
   
   hack.whichSlot = theNode->slotNumber - 1;
   hack.whichPattern = theNode->pattern - 1;

   /*=============================*/
   /* Return the argument bitmap. */
   /*=============================*/
   
   return(AddBitMap(&hack,sizeof(struct factGetVarJN2Call)));
  }
  
/*************************************************************/
/* FactGetVarJN3: Creates the arguments for the routine for  */
/*   retrieving a variable's value from a multifield slot of */
/*   a fact. For this routine, the variable's value must be  */
/*   from a multifield slot that contains at most one        */
/*   multifield variable or contains no multifield variables */
/*   before the variable's value to be retrieved. The        */
/*   retrieval relies on information stored in a partial     */
/*   match, so this retrieval mechanism is used by           */
/*   expressions in the join network or from the RHS of a    */
/*   rule.                                                   */ 
/*************************************************************/
static VOID *FactGetVarJN3(theNode)
  struct lhsParseNode *theNode;
  {
   struct factGetVarJN3Call hack;

   /*===================================================*/
   /* Clear the bitmap for storing the argument values. */
   /*===================================================*/
     
   ClearBitString(&hack,sizeof(struct factGetVarJN3Call));
   
   /*=====================================================*/
   /* Store the position in the partial match from which  */
   /* the fact will be retrieved and the slot in the fact */
   /* from which the value will be retrieved.             */
   /*=====================================================*/

   hack.whichSlot = theNode->slotNumber - 1;
   hack.whichPattern = theNode->pattern - 1;
   
   /*==============================================================*/
   /* If a single field variable value is being retrieved, then... */
   /*==============================================================*/
   
   if ((theNode->type == SF_WILDCARD) || (theNode->type == SF_VARIABLE))
     {
      /*=========================================================*/
      /* If no multifield values occur before the variable, then */
      /* the variable's value can be retrieved based on its      */
      /* offset from the beginning of the slot's value           */
      /* regardless of the number of multifield variables or     */
      /* wildcards following the variable being retrieved.       */
      /*=========================================================*/
      
      if (theNode->multiFieldsBefore == 0)
        {
         hack.fromBeginning = 1;
         hack.fromEnd = 0;
         hack.beginOffset = theNode->singleFieldsBefore;
         hack.endOffset = 0;
        }
        
      /*===============================================*/
      /* Otherwise the variable is retrieved based its */
      /* position relative to the end of the slot.     */
      /*===============================================*/
      
      else
        {
         hack.fromBeginning = 0;
         hack.fromEnd = 1;
         hack.beginOffset = 0;
         hack.endOffset = theNode->singleFieldsAfter;
        }
    
      /*=============================*/
      /* Return the argument bitmap. */
      /*=============================*/

      return(AddBitMap(&hack,sizeof(struct factGetVarJN3Call)));
     }
     
   /*============================================================*/
   /* A multifield variable value is being retrieved. This means */
   /* that there are no other multifield variables or wildcards  */
   /* in the slot. The multifield value is retrieved by storing  */
   /* the number of single field values which come before and    */
   /* after the multifield value. The multifield value can then  */
   /* be retrieved based on the length of the value in the slot  */
   /* and the number of single field values which must occur     */
   /* before and after the multifield value.                     */
   /*============================================================*/
   
   hack.fromBeginning = 1;
   hack.fromEnd = 1;
   hack.beginOffset = theNode->singleFieldsBefore;
   hack.endOffset = theNode->singleFieldsAfter;
     
   /*=============================*/
   /* Return the argument bitmap. */
   /*=============================*/
   
   return(AddBitMap(&hack,sizeof(struct factGetVarJN3Call)));
  }
  
/**************************************************************/
/* FactGetVarPN1: Creates the arguments for the most general  */
/*   routine for retrieving a variable's value from the slot  */
/*   of a fact. The retrieval relies on information stored    */
/*   during fact pattern matching, so this retrieval          */
/*   mechanism is only used by expressions in the pattern     */
/*   network.                                                 */
/**************************************************************/
static VOID *FactGetVarPN1(theNode)
  struct lhsParseNode *theNode;
  {
   struct factGetVarPN1Call hack;

   /*===================================================*/
   /* Clear the bitmap for storing the argument values. */
   /*===================================================*/
   
   ClearBitString(&hack,sizeof(struct factGetVarPN1Call));
   
   /*========================================*/
   /* A slot value of zero indicates that we */
   /* want the pattern address returned.     */
   /*========================================*/
   
   if (theNode->slotNumber <= 0)
     {
      hack.factAddress = 1;
      hack.allFields = 0;
      hack.whichSlot = 0;
      hack.whichField = 0;
     }
     
   /*=====================================================*/
   /* A slot value greater than zero and a field value of */
   /* zero indicate that we want the entire contents of   */
   /* the slot whether it is a single field or multifield */
   /* slot.                                               */
   /*=====================================================*/
   
   else if (theNode->index <= 0)
     {
      hack.factAddress = 0;
      hack.allFields = 1;
      hack.whichSlot = theNode->slotNumber - 1;
      hack.whichField = 0;
     }
     
   /*=============================================*/
   /* A slot value, m, and a field value, n, both */
   /* greater than zero indicate that we want the */
   /* nth field of the mth slot.                  */
   /*=============================================*/
   
   else
     {
      hack.factAddress = 0;
      hack.allFields = 0;
      hack.whichSlot = theNode->slotNumber - 1;
      hack.whichField = theNode->index - 1;
     }
     
   /*=============================*/
   /* Return the argument bitmap. */
   /*=============================*/
   
   return(AddBitMap(&hack,sizeof(struct factGetVarPN1Call)));
  }

/***************************************************************/
/* FactGetVarPN2: Creates the arguments for the routine which  */
/*   retrieves a variable's value from a single field slot of  */
/*   a fact. The retrieval relies on information stored during */
/*   fact pattern matching, so this retrieval mechanism is     */
/*   only used by expressions in the pattern network.          */
/***************************************************************/
static VOID *FactGetVarPN2(theNode)
  struct lhsParseNode *theNode;
  {
   struct factGetVarPN2Call hack;
   
   /*===================================================*/
   /* Clear the bitmap for storing the argument values. */
   /*===================================================*/

   ClearBitString(&hack,sizeof(struct factGetVarPN2Call));
   
   /*=======================================*/
   /* Store the slot in the fact from which */
   /* the value will be retrieved.          */
   /*=======================================*/