factgen.c

来自「clips源代码」· C语言 代码 · 共 1,258 行 · 第 1/4 页

   /* 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 = (unsigned short) (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 = (unsigned short) (theNode->slotNumber - 1);
      hack.whichField = (unsigned short) (theNode->index - 1);
     }

   /*=============================*/
   /* Return the argument bitmap. */
   /*=============================*/

   return(AddBitMap(theEnv,&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(
  void *theEnv,
  struct lhsParseNode *theNode,
  int side)
  {
   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 = (unsigned short) (theNode->slotNumber - 1);

   if (side == LHS)
     { 
      hack.lhs = 1; 
      hack.whichPattern = (unsigned short) theNode->joinDepth;
     }
   else if (side == RHS)
     { 
      hack.rhs = 1; 
      hack.whichPattern = (unsigned short) 0;
     }
   else if (side == NESTED_RHS)
     { 
      hack.rhs = 1; 
      hack.whichPattern = (unsigned short) theNode->joinDepth;
     }
   else
     { hack.whichPattern = (unsigned short) theNode->joinDepth; }

   /*=============================*/
   /* Return the argument bitmap. */
   /*=============================*/

   return(AddBitMap(theEnv,&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(
  void *theEnv,
  struct lhsParseNode *theNode,
  int side)
  {
   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 = (unsigned short) (theNode->slotNumber - 1);

   if (side == LHS)
     { 
      hack.lhs = 1; 
      hack.whichPattern = (unsigned short) theNode->joinDepth;
     }
   else if (side == RHS)
     { 
      hack.rhs = 1; 
      hack.whichPattern = (unsigned short) 0;
     }
   else if (side == NESTED_RHS)
     { 
      hack.rhs = 1; 
      hack.whichPattern = (unsigned short) theNode->joinDepth;
     }
   else
     { hack.whichPattern = (unsigned short) theNode->joinDepth; }

   /*==============================================================*/
   /* 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(theEnv,&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(theEnv,&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(
  void *theEnv,
  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 = (unsigned short) (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 = (unsigned short) (theNode->slotNumber - 1);
      hack.whichField = (unsigned short) (theNode->index - 1);
     }

   /*=============================*/
   /* Return the argument bitmap. */
   /*=============================*/

   return(AddBitMap(theEnv,&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(
  void *theEnv,
  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.          */
   /*=======================================*/

   hack.whichSlot = (unsigned short) (theNode->slotNumber - 1);

   /*=============================*/
   /* Return the argument bitmap. */