factrete.c

NASA 开发使用的一个专家系统

#pragma argsused
#endif
globle BOOLEAN FactPNConstant2(theValue,returnValue)
  VOID *theValue;
  DATA_OBJECT_PTR returnValue;
  {
#if MAC_MPW || MAC_MCW
#pragma unused(returnValue)
#endif
   struct factConstantPN2Call *hack;
   struct field *fieldPtr;
   struct expr *theConstant;
   struct multifield *segmentPtr;

   /*==========================================*/
   /* Retrieve the arguments for the function. */
   /*==========================================*/
   
   hack = (struct factConstantPN2Call *) ValueToBitMap(theValue);
   
   /*==========================================================*/
   /* Extract the value from the specified slot. Note that the */
   /* test to determine the slot's type (multifield) should be */
   /* unnecessary since this routine should only be used for   */
   /* multifield slots.                                        */
   /*==========================================================*/
   
   fieldPtr = &CurrentPatternFact->theProposition.theFields[hack->whichSlot];
   
   if (fieldPtr->type == MULTIFIELD)
     {
      segmentPtr = (struct multifield *) fieldPtr->value;

      if (hack->fromBeginning)
        { fieldPtr = &segmentPtr->theFields[hack->offset]; }
      else
        { 
         fieldPtr = &segmentPtr->theFields[segmentPtr->multifieldLength - 
                    (hack->offset + 1)]; 
        }
     }
   
   /*====================================*/
   /* Compare the value to the constant. */
   /*====================================*/
   
   theConstant = GetFirstArgument();
   if (theConstant->type != fieldPtr->type) return(1 - hack->testForEquality);
   if (theConstant->value != fieldPtr->value) return(1 - hack->testForEquality);
   return(hack->testForEquality);
  }
  
/**************************************************************/
/* FactJNGetVar1: Fact join network function for extracting a */
/*   variable's value. This is the most generalized routine.  */
/**************************************************************/
globle BOOLEAN FactJNGetVar1(theValue,returnValue)
  VOID *theValue;
  DATA_OBJECT_PTR returnValue;
  {
   int theField, theSlot;
   struct fact *factPtr;
   struct field *fieldPtr;
   struct multifieldMarker *marks;
   struct multifield *segmentPtr;
   int extent;
   struct factGetVarJN1Call *hack;

   /*==========================================*/
   /* Retrieve the arguments for the function. */
   /*==========================================*/
   
   hack = (struct factGetVarJN1Call *) ValueToBitMap(theValue);
   
   /*=====================================================*/
   /* Get the pointer to the fact from the partial match. */
   /*=====================================================*/
     
   if (GlobalRHSBinds == NULL)
     { 
      factPtr = (struct fact *) get_nth_pm_match(GlobalLHSBinds,hack->whichPattern)->matchingItem;
      marks = get_nth_pm_match(GlobalLHSBinds,hack->whichPattern)->markers;
     }
   else if ((GlobalJoin->depth - 1) == hack->whichPattern)
     { 
      factPtr = (struct fact *) get_nth_pm_match(GlobalRHSBinds,0)->matchingItem;
      marks = get_nth_pm_match(GlobalRHSBinds,0)->markers;
     }
   else
     {
      factPtr = (struct fact *) get_nth_pm_match(GlobalLHSBinds,hack->whichPattern)->matchingItem;
      marks = get_nth_pm_match(GlobalLHSBinds,hack->whichPattern)->markers;
     }

   /*==========================================================*/
   /* Determine if we want to retrieve the fact address of the */
   /* fact, rather than retrieving a field from the fact.      */
   /*==========================================================*/

   if (hack->factAddress)
     {
      returnValue->type = FACT_ADDRESS;
      returnValue->value = (VOID *) factPtr;
      return(CLIPS_TRUE);
     }
     
   /*=========================================================*/
   /* Determine if we want to retrieve the entire slot value. */
   /*=========================================================*/
     
   if (hack->allFields)
     {
      theSlot = hack->whichSlot;
      fieldPtr = &factPtr->theProposition.theFields[theSlot];
      returnValue->type = fieldPtr->type;
      returnValue->value = fieldPtr->value;
      if (returnValue->type == MULTIFIELD)
        {
         returnValue->begin = 0;
         returnValue->end = ((struct multifield *) fieldPtr->value)->multifieldLength - 1;
        }
        
      return(CLIPS_TRUE);
     }
   
   /*====================================================*/
   /* If the slot being accessed is a single field slot, */
   /* then just return the single value found in that    */
   /* slot. The multifieldMarker data structures do not  */
   /* have to be considered since access to a single     */
   /* field slot is not affected by variable bindings    */
   /* from multifield slots.                             */
   /*====================================================*/
   
   theField = hack->whichField;
   theSlot = hack->whichSlot;
   fieldPtr = &factPtr->theProposition.theFields[theSlot];

   if (fieldPtr->type != MULTIFIELD)
     {
      returnValue->type = fieldPtr->type;
      returnValue->value = fieldPtr->value;
      return(CLIPS_TRUE);
     }

   /*==========================================================*/
   /* Retrieve a value from a multifield slot. First determine */
   /* the range of fields for the variable being retrieved.    */
   /*==========================================================*/
   
   extent = -1;
   theField = AdjustFieldPosition(marks,theField,theSlot,&extent); 
   
   /*=============================================================*/
   /* If a range of values are being retrieved (i.e. a multifield */
   /* variable), then return the values as a multifield.          */
   /*=============================================================*/
   
   if (extent != -1)
     {
      returnValue->type = MULTIFIELD;
      returnValue->value = (VOID *) fieldPtr->value;
      returnValue->begin = theField;
      returnValue->end = theField + extent - 1;
      return(CLIPS_TRUE);
     }

   /*========================================================*/
   /* Otherwise a single field value is being retrieved from */
   /* a multifield slot. Just return the type and value.     */
   /*========================================================*/
   
   segmentPtr = (struct multifield *) factPtr->theProposition.theFields[theSlot].value;
   fieldPtr = &segmentPtr->theFields[theField];

   returnValue->type = fieldPtr->type;
   returnValue->value = fieldPtr->value;
   
   return(CLIPS_TRUE);
  }
  
/*************************************************/
/* FactJNGetVar2: Fact join network function for */
/*   extracting a variable's value. The value    */
/*   extracted is from a single field slot.      */
/*************************************************/
globle BOOLEAN FactJNGetVar2(theValue,returnValue)
  VOID *theValue;
  DATA_OBJECT_PTR returnValue;
  {
   struct fact *factPtr;
   struct factGetVarJN2Call *hack;
   struct field *fieldPtr;

   /*==========================================*/
   /* Retrieve the arguments for the function. */
   /*==========================================*/
   
   hack = (struct factGetVarJN2Call *) ValueToBitMap(theValue);
   
   /*=====================================================*/
   /* Get the pointer to the fact from the partial match. */
   /*=====================================================*/

   if (GlobalRHSBinds == NULL)
     { factPtr = (struct fact *) get_nth_pm_match(GlobalLHSBinds,hack->whichPattern)->matchingItem; }
   else if ((GlobalJoin->depth - 1) == hack->whichPattern)
     { factPtr = (struct fact *) get_nth_pm_match(GlobalRHSBinds,0)->matchingItem; }
   else
     { factPtr = (struct fact *) get_nth_pm_match(GlobalLHSBinds,hack->whichPattern)->matchingItem; }

   /*============================================*/
   /* Extract the value from the specified slot. */
   /*============================================*/
   
   fieldPtr = &factPtr->theProposition.theFields[hack->whichSlot];

   returnValue->type = fieldPtr->type;
   returnValue->value = fieldPtr->value;
   
   return(CLIPS_TRUE);
  }
  
/****************************************************************/
/* FactJNGetVar3: Fact join network function for extracting a   */
/*   variable's value. The value extracted is from a multifield */
/*   slot that contains at most one multifield variable.        */
/****************************************************************/
globle BOOLEAN FactJNGetVar3(theValue,returnValue)
  VOID *theValue;
  DATA_OBJECT_PTR returnValue;
  {
   struct fact *factPtr;
   struct multifield *segmentPtr;
   struct field *fieldPtr;
   struct factGetVarJN3Call *hack;

   /*==========================================*/
   /* Retrieve the arguments for the function. */
   /*==========================================*/
   
   hack = (struct factGetVarJN3Call *) ValueToBitMap(theValue);
   
   /*=====================================================*/
   /* Get the pointer to the fact from the partial match. */
   /*=====================================================*/

   if (GlobalRHSBinds == NULL)
     { factPtr = (struct fact *) get_nth_pm_match(GlobalLHSBinds,hack->whichPattern)->matchingItem; }
   else if ((GlobalJoin->depth - 1) == hack->whichPattern)
     { factPtr = (struct fact *) get_nth_pm_match(GlobalRHSBinds,0)->matchingItem; }
   else
     { factPtr = (struct fact *) get_nth_pm_match(GlobalLHSBinds,hack->whichPattern)->matchingItem; }
   
   /*============================================================*/
   /* Get the multifield value from which the data is retrieved. */
   /*============================================================*/
   
   segmentPtr = (struct multifield *) factPtr->theProposition.theFields[hack->whichSlot].value;

   /*=========================================*/
   /* If the beginning and end flags are set, */ 
   /* then retrieve a multifield value.       */
   /*=========================================*/
   
   if (hack->fromBeginning && hack->fromEnd)
     {
      returnValue->type = MULTIFIELD;
      returnValue->value = (VOID *) segmentPtr;
      returnValue->begin = hack->beginOffset;
      returnValue->end = segmentPtr->multifieldLength - (hack->endOffset + 1);
      return(CLIPS_TRUE);
     }
     
   /*=====================================================*/
   /* Return a single field value from a multifield slot. */
   /*=====================================================*/
   
   if (hack->fromBeginning)
     { fieldPtr = &segmentPtr->theFields[hack->beginOffset]; }
   else
     { fieldPtr = &segmentPtr->theFields[segmentPtr->multifieldLength - (hack->endOffset + 1)]; }
   
   returnValue->type = fieldPtr->type;
   returnValue->value = fieldPtr->value;
   
   return(CLIPS_TRUE);
  }
  
/****************************************************/
/* FactSlotLength: Determines if the length of a    */
/*  multifield slot falls within a specified range. */
/****************************************************/
globle BOOLEAN FactSlotLength(theValue,returnValue)
  VOID *theValue;
  DATA_OBJECT_PTR returnValue;
  {