rulepsr.c

clips源代码

      /*========================================================*/

#if DEVELOPER && DEBUGGING_FUNCTIONS
      if (EnvGetWatchItem(theEnv,"rule-analysis"))
        { DumpRuleAnalysis(theEnv,tempNode); }
#endif

      /*========================================*/
      /* Check to see that logical CEs are used */
      /* appropriately in the LHS of the rule.  */
      /*========================================*/

      if ((logicalJoin = LogicalAnalysis(theEnv,tempNode)) < 0)
        {
         *error = TRUE;
         ReturnDefrule(theEnv,topDisjunct);
         return(NULL);
        }

      /*======================================================*/
      /* Check to see if there are any RHS constraint errors. */
      /*======================================================*/

      if (CheckRHSForConstraintErrors(theEnv,actions,tempNode))
        {
         *error = TRUE;
         ReturnDefrule(theEnv,topDisjunct);
         return(NULL);
        }

      /*=================================================*/
      /* Replace variable references in the RHS with the */
      /* appropriate variable retrieval functions.       */
      /*=================================================*/

      newActions = CopyExpression(theEnv,actions);
      if (ReplaceProcVars(theEnv,"RHS of defrule",newActions,NULL,NULL,
                          ReplaceRHSVariable,(void *) tempNode))
        {
         *error = TRUE;
         ReturnDefrule(theEnv,topDisjunct);
         ReturnExpression(theEnv,newActions);
         return(NULL);
        }

      /*==================================*/
      /* We're finished for this disjunct */
      /* if we're only checking syntax.   */
      /*==================================*/

      if (ConstructData(theEnv)->CheckSyntaxMode)
        {
         ReturnExpression(theEnv,newActions);
         if (emptyLHS)
           { emptyLHS = FALSE; }
         else
           { theLHS = theLHS->bottom; }
         continue;
        }

      /*=================================*/
      /* Install the disjunct's actions. */
      /*=================================*/

      ExpressionInstall(theEnv,newActions);
      packPtr = PackExpression(theEnv,newActions);
      ReturnExpression(theEnv,newActions);

      /*===============================================================*/
      /* Create the pattern and join data structures for the new rule. */
      /*===============================================================*/

      lastJoin = ConstructJoins(theEnv,logicalJoin,tempNode,1);

      /*===================================================================*/
      /* Determine the rule's complexity for use with conflict resolution. */
      /*===================================================================*/

      complexity = RuleComplexity(theEnv,tempNode);

      /*=====================================================*/
      /* Create the defrule data structure for this disjunct */
      /* and put it in the list of disjuncts for this rule.  */
      /*=====================================================*/

      currentDisjunct = CreateNewDisjunct(theEnv,ruleName,localVarCnt,packPtr,complexity,
                                          (unsigned) logicalJoin,lastJoin);

      /*============================================================*/
      /* Place the disjunct in the list of disjuncts for this rule. */
      /* If the disjunct is the first disjunct, then increment the  */
      /* reference counts for the dynamic salience (the expression  */
      /* for the dynamic salience is only stored with the first     */
      /* disjuncts and the other disjuncts refer back to the first  */
      /* disjunct for their dynamic salience value.                 */
      /*============================================================*/

      if (topDisjunct == NULL)
        {
         topDisjunct = currentDisjunct;
         ExpressionInstall(theEnv,topDisjunct->dynamicSalience);
        }
      else lastDisjunct->disjunct = currentDisjunct;

      /*===========================================*/
      /* Move on to the next disjunct of the rule. */
      /*===========================================*/

      lastDisjunct = currentDisjunct;
      
      if (emptyLHS)
        { emptyLHS = FALSE; }
      else
        { theLHS = theLHS->bottom; }
     }

   return(topDisjunct);
  }

/************************************************************************/
/* CreateNewDisjunct: Creates and initializes a defrule data structure. */
/************************************************************************/
static struct defrule *CreateNewDisjunct(
  void *theEnv,
  SYMBOL_HN *ruleName,
  int localVarCnt,
  struct expr *theActions,
  int complexity,
  unsigned logicalJoin,
  struct joinNode *lastJoin)
  {
   struct joinNode *tempJoin;
   struct defrule *newDisjunct;

   /*===================================================*/
   /* Create and initialize the defrule data structure. */
   /*===================================================*/

   newDisjunct = get_struct(theEnv,defrule);
   newDisjunct->header.ppForm = NULL;
   newDisjunct->header.next = NULL;
   newDisjunct->header.usrData = NULL;
   newDisjunct->logicalJoin = NULL;
   newDisjunct->disjunct = NULL;
   newDisjunct->header.name = ruleName;
   IncrementSymbolCount(newDisjunct->header.name);
   newDisjunct->actions = theActions;
   newDisjunct->salience = PatternData(theEnv)->GlobalSalience;
   newDisjunct->afterBreakpoint = 0;
   newDisjunct->watchActivation = 0;
   newDisjunct->watchFiring = 0;
   newDisjunct->executing = 0;
   newDisjunct->complexity = complexity;
   newDisjunct->autoFocus = PatternData(theEnv)->GlobalAutoFocus;
   newDisjunct->dynamicSalience = PatternData(theEnv)->SalienceExpression;
   newDisjunct->localVarCnt = localVarCnt;

   /*=====================================*/
   /* Add a pointer to the rule's module. */
   /*=====================================*/

   newDisjunct->header.whichModule =
      (struct defmoduleItemHeader *)
      GetModuleItem(theEnv,NULL,FindModuleItem(theEnv,"defrule")->moduleIndex);

   /*============================================================*/
   /* Attach the rule's last join to the defrule data structure. */
   /*============================================================*/

   lastJoin->ruleToActivate = newDisjunct;
   newDisjunct->lastJoin = lastJoin;

   /*=================================================*/
   /* Determine the rule's logical join if it exists. */
   /*=================================================*/

   tempJoin = lastJoin;
   while (tempJoin != NULL)
     {
      if (tempJoin->depth == logicalJoin)
        {
         newDisjunct->logicalJoin = tempJoin;
         tempJoin->logicalJoin = TRUE;
        }
      tempJoin = tempJoin->lastLevel;
     }

   /*==================================================*/
   /* Return the newly created defrule data structure. */
   /*==================================================*/

   return(newDisjunct);
  }

/****************************************************************/
/* ReplaceExpressionVariables: Replaces all symbolic references */
/*   to variables (local and global) found in an expression on  */
/*   the RHS of a rule with expressions containing function     */
/*   calls to retrieve the variable's value. Makes the final    */
/*   modifications necessary for handling the modify and        */
/*   duplicate commands.                                        */
/****************************************************************/
static int ReplaceRHSVariable(
  void *theEnv,
  struct expr *list,
  void *VtheLHS)
  {
   struct lhsParseNode *theVariable;

   /*=======================================*/
   /* Handle modify and duplicate commands. */
   /*=======================================*/

#if DEFTEMPLATE_CONSTRUCT
   if (list->type == FCALL)
     {
      if (list->value == (void *) FindFunction(theEnv,"modify"))
        {
         if (UpdateModifyDuplicate(theEnv,list,"modify",VtheLHS) == FALSE)
           return(-1);
        }
      else if (list->value == (void *) FindFunction(theEnv,"duplicate"))
        {
         if (UpdateModifyDuplicate(theEnv,list,"duplicate",VtheLHS) == FALSE)
           return(-1);
        }

      return(0);
     }

#endif

   if ((list->type != SF_VARIABLE) && (list->type != MF_VARIABLE))
     { return(FALSE); }

   /*===============================================================*/
   /* Check to see if the variable is bound on the LHS of the rule. */
   /*===============================================================*/

   theVariable = FindVariable((SYMBOL_HN *) list->value,(struct lhsParseNode *) VtheLHS);
   if (theVariable == NULL) return(FALSE);

   /*================================================*/
   /* Replace the variable reference with a function */
   /* call to retrieve the variable.                 */
   /*================================================*/

   if (theVariable->patternType != NULL)
     { (*theVariable->patternType->replaceGetJNValueFunction)(theEnv,list,theVariable,LHS); }
   else
     { return(FALSE); }

   /*=================================================================*/
   /* Return TRUE to indicate the variable was successfully replaced. */
   /*=================================================================*/

   return(TRUE);
  }

/*******************************************************/
/* ParseRuleRHS: Coordinates all the actions necessary */
/*   for parsing the RHS of a rule.                    */
/*******************************************************/
static struct expr *ParseRuleRHS(
  void *theEnv,
  char *readSource)
  {
   struct expr *actions;
   struct token theToken;

   /*=========================================================*/
   /* Process the actions on the right hand side of the rule. */
   /*=========================================================*/

   SavePPBuffer(theEnv,"\n   ");
   SetIndentDepth(theEnv,3);

   actions = GroupActions(theEnv,readSource,&theToken,TRUE,NULL,FALSE);

   if (actions == NULL) return(NULL);

   /*=============================*/
   /* Reformat the closing token. */
   /*=============================*/

   PPBackup(theEnv);
   PPBackup(theEnv);
   SavePPBuffer(theEnv,theToken.printForm);

   /*======================================================*/
   /* Check for the closing right parenthesis of the rule. */
   /*======================================================*/

   if (theToken.type != RPAREN)
     {
      SyntaxErrorMessage(theEnv,"defrule");
      ReturnExpression(theEnv,actions);
      return(NULL);
     }

   /*========================*/
   /* Return the rule's RHS. */
   /*========================*/

   return(actions);
  }

/************************************************************/
/* RuleComplexity: Returns the complexity of a rule for use */
/*   by the LEX and MEA conflict resolution strategies.     */
/************************************************************/
static int RuleComplexity(
  void *theEnv,
  struct lhsParseNode *theLHS)
  {
   struct lhsParseNode *thePattern, *tempPattern;
   int complexity = 0;

   while (theLHS != NULL)
     {
      complexity += 1; /* Add 1 for each pattern. */
      complexity += ExpressionComplexity(theEnv,theLHS->networkTest);
      thePattern = theLHS->right;
      while (thePattern != NULL)
        {
         if (thePattern->multifieldSlot)
           {
            tempPattern = thePattern->bottom;
            while (tempPattern != NULL)
              {
               complexity += ExpressionComplexity(theEnv,tempPattern->networkTest);
               tempPattern = tempPattern->right;
              }
           }
         else
           { complexity += ExpressionComplexity(theEnv,thePattern->networkTest); }
         thePattern = thePattern->right;
        }
      theLHS = theLHS->bottom;
     }

   return(complexity);
  }