factcom.c

NASA 开发使用的一个专家系统

   struct fact *theFact;
   FILE *filePtr;
   struct defmodule *theModule;
   DATA_OBJECT_PTR theDOArray;
   int count, i, printFact, error;

   /*======================================================*/
   /* Open the file. Use either "fast save" or I/O Router. */
   /*======================================================*/

   if ((filePtr = fopen(fileName,"w")) == NULL)
     {
      OpenErrorMessage("save-facts",fileName);
      return(CLIPS_FALSE);
     }

   SetFastSave(filePtr);

   /*===========================================*/
   /* Set the print flags so that addresses and */
   /* strings are printed properly to the file. */
   /*===========================================*/

   tempValue1 = PreserveEscapedCharacters;
   PreserveEscapedCharacters = CLIPS_TRUE;
   tempValue2 = AddressesToStrings;
   AddressesToStrings = CLIPS_TRUE;
   tempValue3 = InstanceAddressesToNames;
   InstanceAddressesToNames = CLIPS_TRUE;

   /*===================================================*/
   /* Determine the list of specific facts to be saved. */
   /*===================================================*/
   
   theDOArray = GetSaveFactsDeftemplateNames(theList,saveCode,&count,&error);
   
   if (error)
     {
      PreserveEscapedCharacters = tempValue1;
      AddressesToStrings = tempValue2;
      InstanceAddressesToNames = tempValue3;
      fclose(filePtr);
      SetFastSave(NULL);
      return(CLIPS_FALSE);
     }
     
   /*=================*/
   /* Save the facts. */
   /*=================*/
      
   theModule = ((struct defmodule *) GetCurrentModule());
   
   for (theFact = (struct fact *) GetNextFactInScope(NULL);
        theFact != NULL;
        theFact = (struct fact *) GetNextFactInScope(theFact))
     {
      /*===========================================================*/
      /* If we're doing a local save and the facts's corresponding */
      /* deftemplate isn't in the current module, then don't save  */
      /* the fact.                                                 */
      /*===========================================================*/
      
      if ((saveCode == LOCAL_SAVE) &&
          (theFact->whichDeftemplate->header.whichModule->theModule != theModule))
        { printFact = CLIPS_FALSE; }
        
      /*=====================================================*/
      /* Otherwise, if the list of facts to be printed isn't */
      /* restricted, then set the print flag to TRUE.        */
      /*=====================================================*/
      
      else if (theList == NULL)
        { printFact = CLIPS_TRUE; }
        
      /*=======================================================*/
      /* Otherwise see if the fact's corresponding deftemplate */
      /* is in the list of deftemplates whose facts are to be  */
      /* saved. If it's in the list, then set the print flag   */
      /* to TRUE, otherwise set it to FALSE.                   */
      /*=======================================================*/
      
      else 
        {
         printFact = CLIPS_FALSE;
         for (i = 0; i < count; i++)
           {
            if (theDOArray[i].value == (VOID *) theFact->whichDeftemplate)
              {
               printFact = CLIPS_TRUE;
               break;
              }
           }
        }
         
      /*===================================*/
      /* If the print flag is set to TRUE, */
      /* then save the fact to the file.   */
      /*===================================*/
      
      if (printFact)
        { 
         PrintFact((char *) filePtr,theFact);
         PrintCLIPS((char *) filePtr,"\n");
        }
     }
     
   /*==========================*/
   /* Restore the print flags. */
   /*==========================*/
   
   PreserveEscapedCharacters = tempValue1;
   AddressesToStrings = tempValue2;
   InstanceAddressesToNames = tempValue3;
   
   /*=================*/
   /* Close the file. */
   /*=================*/

   fclose(filePtr);
   SetFastSave(NULL);
   
   /*==================================*/
   /* Free the deftemplate name array. */
   /*==================================*/
   
   if (theList != NULL) rm3(theDOArray,(long) sizeof(DATA_OBJECT) * count);

   /*===================================*/
   /* Return TRUE to indicate no errors */
   /* occurred while saving the facts.  */
   /*===================================*/
   
   return(CLIPS_TRUE);
  }
  
/*******************************************************************/
/* GetSaveFactsDeftemplateNames: Retrieves the list of deftemplate */
/*   names for saving specific facts with the save-facts command.  */
/*******************************************************************/
static DATA_OBJECT_PTR GetSaveFactsDeftemplateNames(theList,saveCode,count,error)
  struct expr *theList;
  int saveCode;
  int *count;
  int *error;
  {
   struct expr *tempList;
   DATA_OBJECT_PTR theDOArray;
   int i, tempCount;
   struct deftemplate *theDeftemplate;
   
   /*=============================*/
   /* Initialize the error state. */
   /*=============================*/
   
   *error = CLIPS_FALSE;
   
   /*=====================================================*/
   /* If no deftemplate names were specified as arguments */
   /* then the deftemplate name list is empty.            */
   /*=====================================================*/
   
   if (theList == NULL) 
     {
      *count = 0;
      return(NULL);
     }
   
   /*======================================*/
   /* Determine the number of deftemplate  */
   /* names to be stored in the name list. */
   /*======================================*/
               
   for (tempList = theList, *count = 0;
        tempList != NULL;
        tempList = tempList->nextArg, (*count)++)
     { /* Do Nothing */ }
        
   /*=========================================*/
   /* Allocate the storage for the name list. */
   /*=========================================*/
   
   theDOArray = (DATA_OBJECT_PTR) gm3((long) sizeof(DATA_OBJECT) * *count);
   
   /*=====================================*/
   /* Loop through each of the arguments. */
   /*=====================================*/
   
   for (tempList = theList, i = 0; 
        i < *count; 
        tempList = tempList->nextArg, i++)
     {
      /*========================*/
      /* Evaluate the argument. */
      /*========================*/
      
      EvaluateExpression(tempList,&theDOArray[i]);
      
      if (EvaluationError)
        {
         *error = CLIPS_TRUE;
         rm3(theDOArray,(long) sizeof(DATA_OBJECT) * *count);
         return(NULL);
        }
     
      /*======================================*/
      /* A deftemplate name must be a symbol. */
      /*======================================*/
      
      if (theDOArray[i].type != SYMBOL)
        { 
         *error = CLIPS_TRUE;
         ExpectedTypeError1("save-facts",3+i,"symbol");
         rm3(theDOArray,(long) sizeof(DATA_OBJECT) * *count);
         return(NULL);
        }
         
      /*===================================================*/
      /* Find the deftemplate. For a local save, look only */
      /* in the current module. For a visible save, look   */
      /* in all visible modules.                           */
      /*===================================================*/
      
      if (saveCode == LOCAL_SAVE)
        {
         theDeftemplate = (struct deftemplate *)
                         FindDeftemplate(ValueToString(theDOArray[i].value));
         if (theDeftemplate == NULL)
           {
            *error = CLIPS_TRUE;
            ExpectedTypeError1("save-facts",3+i,"local deftemplate name");
            rm3(theDOArray,(long) sizeof(DATA_OBJECT) * *count);
            return(NULL);
           }
        }
      else if (saveCode == VISIBLE_SAVE)
        {
         theDeftemplate = (struct deftemplate *)
           FindImportedConstruct("deftemplate",NULL,
                                 ValueToString(theDOArray[i].value),
                                 &tempCount,CLIPS_TRUE,NULL);
         if (theDeftemplate == NULL)
           {
            *error = CLIPS_TRUE;
            ExpectedTypeError1("save-facts",3+i,"visible deftemplate name");
            rm3(theDOArray,(long) sizeof(DATA_OBJECT) * *count);
            return(NULL);
           }
        }
        
      /*==================================*/
      /* Add a pointer to the deftemplate */
      /* to the array being created.      */
      /*==================================*/
               
      theDOArray[i].type = DEFTEMPLATE_PTR;
      theDOArray[i].value = (VOID *) theDeftemplate;
     }
     
   /*===================================*/
   /* Return the array of deftemplates. */
   /*===================================*/
   
   return(theDOArray);
  }
  
/***********************************************************/
/* LoadFacts: C access routine for the load-facts command. */
/***********************************************************/
globle BOOLEAN LoadFacts(fileName)
  char *fileName;
  {
   FILE *filePtr;
   struct token theToken;
   struct expr *testPtr;
   DATA_OBJECT rv;

   /*======================================================*/
   /* Open the file. Use either "fast save" or I/O Router. */
   /*======================================================*/

   if ((filePtr = fopen(fileName,"r")) == NULL)
     {
      OpenErrorMessage("load-facts",fileName);
      return(CLIPS_FALSE);
     }

   SetFastLoad(filePtr);

   /*=================*/
   /* Load the facts. */
   /*=================*/

   theToken.type = LPAREN;
   while (theToken.type != STOP)
     {
      testPtr = StandardLoadFact((char *) filePtr,&theToken);
      if (testPtr == NULL) theToken.type = STOP;
      else EvaluateExpression(testPtr,&rv);
      ReturnExpression(testPtr);
     }

   /*=================*/
   /* Close the file. */
   /*=================*/

   SetFastLoad(NULL);
   fclose(filePtr);

   /*================================================*/
   /* Return TRUE if no error occurred while loading */
   /* the facts, otherwise return FALSE.             */
   /*================================================*/
   
   if (EvaluationError) return(CLIPS_FALSE);
   return(CLIPS_TRUE);
  }

/***********************************************************/
/* LoadFactsFromString: C access routine                   */
/***********************************************************/
globle BOOLEAN LoadFactsFromString(theString,theMax)
  char * theString;
  int theMax;
  {
   char * theStrRouter = "*** load-facts-from-string ***";
   struct token theToken;
   struct expr *testPtr;
   DATA_OBJECT rv;

   /*==========================*/
   /* Initialize string router */
   /*==========================*/

   if ((theMax == -1) ? (!OpenStringSource(theStrRouter,theString,0)) :
                        (!OpenTextSource(theStrRouter,theString,0,theMax)))
     return(CLIPS_FALSE);

   /*=================*/
   /* Load the facts. */
   /*=================*/

   theToken.type = LPAREN;
   while (theToken.type != STOP)
     {
      testPtr = StandardLoadFact(theStrRouter,&theToken);
      if (testPtr == NULL) theToken.type = STOP;
      else EvaluateExpression(testPtr,&rv);
      ReturnExpression(testPtr);
     }

   /*=================*/
   /* Close router.   */
   /*=================*/

   CloseStringSource(theStrRouter);

   /*================================================*/
   /* Return TRUE if no error occurred while loading */
   /* the facts, otherwise return FALSE.             */
   /*================================================*/
   
   if (EvaluationError) return(CLIPS_FALSE);
   return(CLIPS_TRUE);
  }

/**************************************************************************/
/* StandardLoadFact: Loads a single fact from the specified logical name. */
/**************************************************************************/
static struct expr *StandardLoadFact(logicalName,theToken)
  char *logicalName;
  struct token *theToken;
  {
   int error = CLIPS_FALSE;
   struct expr *temp;

   GetToken(logicalName,theToken);
   if (theToken->type != LPAREN) return(NULL);

   temp = GenConstant(FCALL,FindFunction("assert"));
   temp->argList = GetRHSPattern(logicalName,theToken,&error,
                                  CLIPS_TRUE,CLIPS_FALSE,CLIPS_TRUE,RPAREN);

   if (error == CLIPS_TRUE)
     {
      PrintCLIPS(WERROR,"Function load-facts encountered an error\n");
      SetEvaluationError(CLIPS_TRUE);
      ReturnExpression(temp);
      return(NULL);
     }

   if (ExpressionContainsVariables(temp,CLIPS_TRUE))
     {
      ReturnExpression(temp);
      return(NULL);
     }

   return(temp);
  }

#if (! RUN_TIME)

/****************************************************************/
/* AssertParse: Driver routine for parsing the assert function. */
/****************************************************************/
static struct expr *AssertParse(top,logicalName)
  struct expr *top;
  char *logicalName;
  {
   int error;
   struct expr *rv;
   struct token theToken;

   ReturnExpression(top);
   SavePPBuffer(" ");
   IncrementIndentDepth(8);
   rv = BuildRHSAssert(logicalName,&theToken,&error,CLIPS_TRUE,CLIPS_TRUE,"assert command");
   DecrementIndentDepth(8);
   return(rv);
  }

#endif /* (! RUN_TIME) */

#endif /* DEFTEMPLATE_CONSTRUCT */