rulelhs.c

clips源代码

       (connectorValue == NOT_CE))
     {
      theNode->type = connectorValue;
      theNode->right = theGroup;
     }

   /*=================================================================*/
   /* Wrap two not CEs around the patterns contained in an exists CE. */
   /*=================================================================*/

   else if (connectorValue == EXISTS_CE)
     {
      theNode->type = NOT_CE;

      theNode->right = GetLHSParseNode(theEnv);
      theNode->right->type = NOT_CE;
      theNode->right->logical = logical;

      if (theGroup->bottom != NULL)
        {
         theNode->right->right = GetLHSParseNode(theEnv);
         theNode->right->right->type = AND_CE;
         theNode->right->right->logical = logical;
         theNode->right->right->right = theGroup;
        }
      else
        { theNode->right->right = theGroup; }
     }

   /*==================================================*/
   /* For a forall CE, wrap a not CE around all of the */
   /* CEs and a not CE around the 2nd through nth CEs. */
   /*==================================================*/

   else if (connectorValue == FORALL_CE)
     {
      theNode->type = NOT_CE;

      tempNode = theGroup->bottom;
      theGroup->bottom = NULL;

      theNode->right = GetLHSParseNode(theEnv);
      theNode->right->type = AND_CE;
      theNode->right->logical = logical;
      theNode->right->right = theGroup;

      theGroup = tempNode;

      theNode->right->right->bottom = GetLHSParseNode(theEnv);
      theNode->right->right->bottom->type = NOT_CE;
      theNode->right->right->bottom->logical = logical;

      tempNode = theNode->right->right->bottom;

      if (theGroup->bottom == NULL)
        { tempNode->right = theGroup; }
      else
        {
         tempNode->right = GetLHSParseNode(theEnv);
         tempNode->right->type = AND_CE;
         tempNode->right->logical = logical;
         tempNode->right->right = theGroup;
        }
     }

   /*================*/
   /* Return the CE. */
   /*================*/

   return(theNode);
  }

/***********************************************/
/* GroupPatterns: Groups a series of connected */
/*   conditional elements together.            */
/***********************************************/
static struct lhsParseNode *GroupPatterns(
  void *theEnv,
  char *readSource,
  int terminator,
  char *terminatorString,
  int *error)
  {
   struct lhsParseNode *lastNode, *newNode, *theNode;

   lastNode = theNode = NULL;

   while (TRUE)
     {
      /*==================*/
      /* Get the next CE. */
      /*==================*/

      newNode = LHSPattern(theEnv,readSource,terminator,terminatorString,
                           error,FALSE,NULL,NULL);

      /*=======================================================*/
      /* If an error occurred, release any LHS data structures */
      /* previously allocated by this routine.                 */
      /*=======================================================*/

      if (*error)
        {
         ReturnLHSParseNodes(theEnv,theNode);
         return(NULL);
        }

      /*===============================================*/
      /* A NULL value for the CE just parsed indicates */
      /* that the terminator for the group of patterns */
      /* was encountered (either a "=>" or a ")".      */
      /*===============================================*/

      if (newNode == NULL)
        {
         PPBackup(theEnv);
         PPBackup(theEnv);
         if (terminator == RPAREN)
           { SavePPBuffer(theEnv,terminatorString); }
         else
           {
            PPCRAndIndent(theEnv);
            SavePPBuffer(theEnv,terminatorString);
           }

         return(theNode);
        }

      /*============================*/
      /* Add the new CE to the list */
      /* of CEs being grouped.      */
      /*============================*/

      if (lastNode == NULL)
        { theNode = newNode; }
      else
        { lastNode->bottom = newNode; }

      lastNode = newNode;

      /*======================================*/
      /* Fix the pretty print representation. */
      /*======================================*/

      PPCRAndIndent(theEnv);
     }
  }

/**************************************************************/
/* TestPattern: Handles parsing of test conditional elements. */
/*                                                            */
/* <test-CE> ::= (test <function-call>)                       */
/**************************************************************/
static struct lhsParseNode *TestPattern(
  void *theEnv,
  char *readSource,
  int *error)
  {
   struct lhsParseNode *theNode;
   struct token theToken;
   struct expr *theExpression;

   /*================================================*/
   /* Create the data specification for the test CE. */
   /*================================================*/

   SavePPBuffer(theEnv," ");
   theNode = GetLHSParseNode(theEnv);
   theNode->type = TEST_CE;
   theExpression = Function0Parse(theEnv,readSource);
   theNode->expression = ExpressionToLHSParseNodes(theEnv,theExpression);
   ReturnExpression(theEnv,theExpression);

   if (theNode->expression == NULL)
     {
      *error = TRUE;
      ReturnLHSParseNodes(theEnv,theNode);
      return(NULL);
     }

   /*=========================================================*/
   /* Check for the closing right parenthesis of the test CE. */
   /*=========================================================*/

   GetToken(theEnv,readSource,&theToken);
   if (theToken.type != RPAREN)
     {
      SyntaxErrorMessage(theEnv,"test conditional element");
      *error = TRUE;
      ReturnLHSParseNodes(theEnv,theNode);
      return(NULL);
     }

   /*=====================*/
   /* Return the test CE. */
   /*=====================*/

   return(theNode);
  }

/****************************************************************/
/* AssignmentParse: Finishes the parsing of pattern conditional */
/*   elements that have been bound to a  variable.              */
/*                                                              */
/* <assigned-pattern-CE> ::= ?<variable-symbol> <- <pattern-CE> */
/****************************************************************/
static struct lhsParseNode *AssignmentParse(
  void *theEnv,
  char *readSource,
  SYMBOL_HN *factAddress,
  int *error)
  {
   struct lhsParseNode *theNode;
   struct token theToken;

   /*=====================================================*/
   /* Patterns cannot be bound if they are with a not CE. */
   /*=====================================================*/

   if (PatternData(theEnv)->WithinNotCE)
     {
      PrintErrorID(theEnv,"RULELHS",2,TRUE);
      EnvPrintRouter(theEnv,WERROR,"A pattern CE cannot be bound to a pattern-address within a not CE\n");
      *error = TRUE;
      return(NULL);
     }

   /*===============================================*/
   /* Check for binder token, "<-", after variable. */
   /*===============================================*/

   SavePPBuffer(theEnv," ");

   GetToken(theEnv,readSource,&theToken);

   if ((theToken.type == SYMBOL) ? (strcmp(ValueToString(theToken.value),"<-") != 0) :
                                   TRUE)
     {
      SyntaxErrorMessage(theEnv,"binding patterns");
      *error = TRUE;
      return(NULL);
     }

   SavePPBuffer(theEnv," ");

   /*================================================*/
   /* Check for opening left parenthesis of pattern. */
   /*================================================*/

   GetToken(theEnv,readSource,&theToken);
   if (theToken.type != LPAREN)
     {
      SyntaxErrorMessage(theEnv,"binding patterns");
      *error = TRUE;
      return(NULL);
     }

   /*======================================================*/
   /* Parse the pattern and return the data specification. */
   /*======================================================*/

   GetToken(theEnv,readSource,&theToken);

   theNode = SimplePatternParse(theEnv,readSource,&theToken,error);

   if (*error == TRUE)
     {
      ReturnLHSParseNodes(theEnv,theNode);
      return(NULL);
     }

   /*=============================================*/
   /* Store the name of the variable to which the */
   /* pattern is bound and return the pattern.    */
   /*=============================================*/

   theNode->value = (void *) factAddress;
   return(theNode);
  }

/************************************************************/
/* TagLHSLogicalNodes: Marks all *and*, *or*, and *not* CEs */
/*   contained within a logical CE as having the properties */
/*   associated with a logical CE.                          */
/************************************************************/
static void TagLHSLogicalNodes(
  struct lhsParseNode *nodePtr)
  {
   while (nodePtr != NULL)
     {
      nodePtr->logical = TRUE;
      if ((nodePtr->type == AND_CE) ||
          (nodePtr->type == OR_CE) ||
          (nodePtr->type == NOT_CE))
        { TagLHSLogicalNodes(nodePtr->right); }
      nodePtr = nodePtr->bottom;
     }
  }

/***********************************************************/
/* SimplePatternParse: Parses a simple pattern (an opening */
/*   parenthesis followed by one or more fields followed   */
/*   by a closing parenthesis).                            */
/*                                                         */
/* <pattern-CE> ::= <ordered-pattern-CE> |                 */
/*                  <template-pattern-CE>                  */
/***********************************************************/
static struct lhsParseNode *SimplePatternParse(
  void *theEnv,
  char *readSource,
  struct token *theToken,
  int *error)
  {
   struct lhsParseNode *theNode;
   struct patternParser *tempParser;

   /*=================================================*/
   /* The first field of a pattern must be a symbol.  */
   /* In addition, the symbols ":" and "=" can not    */
   /* be used because they have special significance. */
   /*=================================================*/

   if (theToken->type != SYMBOL)
     {
      SyntaxErrorMessage(theEnv,"the first field of a pattern");
      *error = TRUE;
      return(NULL);
     }
   else if ((strcmp(ValueToString(theToken->value),"=") == 0) ||
            (strcmp(ValueToString(theToken->value),":") == 0))
     {
      SyntaxErrorMessage(theEnv,"the field field of a pattern");
      *error = TRUE;
      return(NULL);
     }

   /*===============================================*/
   /* Construct the topmost node of the pattern CE. */
   /*===============================================*/

   theNode = GetLHSParseNode(theEnv);
   theNode->type = PATTERN_CE;
   theNode->negated = FALSE;
   theNode->exists = FALSE;

   /*======================================================*/
   /* Search for a pattern parser that claims the pattern. */
   /*======================================================*/

   for (tempParser = PatternData(theEnv)->ListOfPatternParsers;
        tempParser != NULL;
        tempParser = tempParser->next)
     {
      if ((*tempParser->recognizeFunction)((SYMBOL_HN *) theToken->value))
        {
         theNode->patternType = tempParser;
         theNode->right = (*tempParser->parseFunction)(theEnv,readSource,theToken);
         if (theNode->right == NULL)
           {
            *error = TRUE;
            ReturnLHSParseNodes(theEnv,theNode);
            return(NULL);
           }

         PropagatePatternType(theNode,tempParser);
         return(theNode);
        }
     }

   /*=================================*/
   /* If a pattern parser couldn't be */
   /* found, then signal an error.    */
   /*=================================*/

   *error = TRUE;
   SyntaxErrorMessage(theEnv,"the field field of a pattern");
   ReturnLHSParseNodes(theEnv,theNode);
   return(NULL);
  }

/**************************************************************/
/* PropagatePatternType: Sets the selfPattern field for all   */
/*   lhsParseNodes in a linked list of those data structures. */
/**************************************************************/
globle void PropagatePatternType(
  struct lhsParseNode *theLHS,
  struct patternParser *theParser)
  {
   while (theLHS != NULL)
     {
      theLHS->patternType = theParser;
      if (theLHS->right != NULL) PropagatePatternType(theLHS->right,theParser);
      if (theLHS->expression != NULL) PropagatePatternType(theLHS->expression,theParser);
      theLHS = theLHS->bottom;
     }
  }

#endif /* (! RUN_TIME) && (! BLOAD_ONLY) &&  DEFRULE_CONSTRUCT */