rulecstr.c

clips源代码

   /*******************************************************/
   /*      "C" Language Integrated Production System      */
   /*                                                     */
   /*             CLIPS Version 6.24  06/05/06            */
   /*                                                     */
   /*              RULE CONSTRAINTS MODULE                */
   /*******************************************************/

/*************************************************************/
/* Purpose: Provides routines for detecting constraint       */
/*   conflicts in the LHS and RHS of rules.                  */
/*                                                           */
/* Principal Programmer(s):                                  */
/*      Gary D. Riley                                        */
/*                                                           */
/* Contributing Programmer(s):                               */
/*                                                           */
/* Revision History:                                         */
/*                                                           */
/*      6.24: Renamed BOOLEAN macro type to intBool.         */
/*                                                           */
/*************************************************************/

#define _RULECSTR_SOURCE_

#include "setup.h"

#if (! RUN_TIME) && (! BLOAD_ONLY) && DEFRULE_CONSTRUCT

#include <stdio.h>
#define _STDIO_INCLUDED_

#include "analysis.h"
#include "cstrnchk.h"
#include "cstrnops.h"
#include "cstrnutl.h"
#include "envrnmnt.h"
#include "extnfunc.h"
#include "prcdrpsr.h"
#include "reorder.h"
#include "router.h"
#include "rulepsr.h"

#include "rulecstr.h"

/***************************************/
/* LOCAL INTERNAL FUNCTION DEFINITIONS */
/***************************************/

   static intBool                 CheckForUnmatchableConstraints(void *,struct lhsParseNode *,int);
   static intBool                 MultifieldCardinalityViolation(void *,struct lhsParseNode *);
   static struct lhsParseNode    *UnionVariableConstraints(void *,struct lhsParseNode *,
                                                     struct lhsParseNode *);
   static struct lhsParseNode    *AddToVariableConstraints(void *,struct lhsParseNode *,
                                                    struct lhsParseNode *);
   static void                    ConstraintConflictMessage(void *,struct symbolHashNode *,
                                                            int,int,struct symbolHashNode *);
   static intBool                 CheckArgumentForConstraintError(void *,struct expr *,struct expr*,
                                                                  int,struct FunctionDefinition *,
                                                                  struct lhsParseNode *);

/***********************************************************/
/* CheckForUnmatchableConstraints: Determines if a LHS CE  */
/*   node contains unmatchable constraints. Return TRUE if */
/*   there are unmatchable constraints, otherwise FALSE.   */
/***********************************************************/
static intBool CheckForUnmatchableConstraints(
  void *theEnv,
  struct lhsParseNode *theNode,
  int whichCE)
  {
   if (EnvGetStaticConstraintChecking(theEnv) == FALSE) return(FALSE);

   if (UnmatchableConstraint(theNode->constraints))
     {
      ConstraintConflictMessage(theEnv,(SYMBOL_HN *) theNode->value,whichCE,
                                theNode->index,theNode->slot);
      return(TRUE);
     }

   return(FALSE);
  }

/******************************************************/
/* ConstraintConflictMessage: Error message used when */
/*   a constraint restriction for a slot prevents any */
/*   value from matching the pattern constraint.      */
/******************************************************/
static void ConstraintConflictMessage(
  void *theEnv,
  struct symbolHashNode *variableName,
  int thePattern,
  int theField,
  struct symbolHashNode *theSlot)
  {
   /*=========================*/
   /* Print the error header. */
   /*=========================*/

   PrintErrorID(theEnv,"RULECSTR",1,TRUE);

   /*======================================================*/
   /* Print the variable name (if available) and CE number */
   /* for which the constraint violation occurred.         */
   /*======================================================*/

   if (variableName != NULL)
     {
      EnvPrintRouter(theEnv,WERROR,"Variable ?");
      EnvPrintRouter(theEnv,WERROR,ValueToString(variableName));
      EnvPrintRouter(theEnv,WERROR," in CE #");
      PrintLongInteger(theEnv,WERROR,(long int) thePattern);
     }
   else
     {
      EnvPrintRouter(theEnv,WERROR,"Pattern #");
      PrintLongInteger(theEnv,WERROR,(long int) thePattern);
     }

   /*=======================================*/
   /* Print the slot name or field position */
   /* in which the violation occurred.      */
   /*=======================================*/

   if (theSlot == NULL)
     {
      EnvPrintRouter(theEnv,WERROR," field #");
      PrintLongInteger(theEnv,WERROR,(long int) theField);
     }
   else
     {
      EnvPrintRouter(theEnv,WERROR," slot ");
      EnvPrintRouter(theEnv,WERROR,ValueToString(theSlot));
     }

   /*======================================*/
   /* Print the rest of the error message. */
   /*======================================*/

   EnvPrintRouter(theEnv,WERROR,"\nhas constraint conflicts which make the pattern unmatchable.\n");
  }

/***************************************************************/
/* MultifieldCardinalityViolation: Determines if a cardinality */
/*   violation has occurred for a LHS CE node.                 */
/***************************************************************/
static intBool MultifieldCardinalityViolation(
  void *theEnv,
  struct lhsParseNode *theNode)
  {
   struct lhsParseNode *tmpNode;
   struct expr *tmpMax;
   long minFields = 0;
   long maxFields = 0;
   int posInfinity = FALSE;
   CONSTRAINT_RECORD *newConstraint, *tempConstraint;

   /*================================*/
   /* A single field slot can't have */
   /* a cardinality violation.       */
   /*================================*/

   if (theNode->multifieldSlot == FALSE) return(FALSE);

   /*=============================================*/
   /* Determine the minimum and maximum number of */
   /* fields the slot could contain based on the  */
   /* slot constraints found in the pattern.      */
   /*=============================================*/

   for (tmpNode = theNode->bottom;
        tmpNode != NULL;
        tmpNode = tmpNode->right)
     {
      /*====================================================*/
      /* A single field variable increases both the minimum */
      /* and maximum number of fields by one.               */
      /*====================================================*/

      if ((tmpNode->type == SF_VARIABLE) ||
          (tmpNode->type == SF_WILDCARD))
        {
         minFields++;
         maxFields++;
        }

      /*=================================================*/
      /* Otherwise a multifield wildcard or variable has */
      /* been encountered. If it is constrained then use */
      /* minimum and maximum number of fields constraint */
      /* associated with this LHS node.                  */
      /*=================================================*/

      else if (tmpNode->constraints != NULL)
        {
         /*=======================================*/
         /* The lowest minimum of all the min/max */
         /* pairs will be the first in the list.  */
         /*=======================================*/

         if (tmpNode->constraints->minFields->value != SymbolData(theEnv)->NegativeInfinity)
           { minFields += (long) ValueToLong(tmpNode->constraints->minFields->value); }

         /*=========================================*/
         /* The greatest maximum of all the min/max */
         /* pairs will be the last in the list.     */
         /*=========================================*/

         tmpMax = tmpNode->constraints->maxFields;
         while (tmpMax->nextArg != NULL) tmpMax = tmpMax->nextArg;
         if (tmpMax->value == SymbolData(theEnv)->PositiveInfinity)
           { posInfinity = TRUE; }
         else
           { maxFields += (long) ValueToLong(tmpMax->value); }
        }

      /*================================================*/
      /* Otherwise an unconstrained multifield wildcard */
      /* or variable increases the maximum number of    */
      /* fields to positive infinity.                   */
      /*================================================*/

      else
        { posInfinity = TRUE; }
     }

   /*==================================================================*/
   /* Create a constraint record for the cardinality of the sum of the */
   /* cardinalities of the restrictions inside the multifield slot.    */
   /*==================================================================*/

   if (theNode->constraints == NULL) tempConstraint = GetConstraintRecord(theEnv);
   else tempConstraint = CopyConstraintRecord(theEnv,theNode->constraints);
   ReturnExpression(theEnv,tempConstraint->minFields);
   ReturnExpression(theEnv,tempConstraint->maxFields);
   tempConstraint->minFields = GenConstant(theEnv,INTEGER,EnvAddLong(theEnv,(long long) minFields));
   if (posInfinity) tempConstraint->maxFields = GenConstant(theEnv,SYMBOL,SymbolData(theEnv)->PositiveInfinity);
   else tempConstraint->maxFields = GenConstant(theEnv,INTEGER,EnvAddLong(theEnv,(long long) maxFields));

   /*================================================================*/
   /* Determine the final cardinality for the multifield slot by     */
   /* intersecting the cardinality sum of the restrictions within    */
   /* the multifield slot with the original cardinality of the slot. */
   /*================================================================*/

   newConstraint = IntersectConstraints(theEnv,theNode->constraints,tempConstraint);
   if (theNode->derivedConstraints) RemoveConstraint(theEnv,theNode->constraints);
   RemoveConstraint(theEnv,tempConstraint);
   theNode->constraints = newConstraint;
   theNode->derivedConstraints = TRUE;

   /*===================================================================*/
   /* Determine if the final cardinality for the slot can be satisfied. */
   /*===================================================================*/

   if (EnvGetStaticConstraintChecking(theEnv) == FALSE) return(FALSE);
   if (UnmatchableConstraint(newConstraint)) return(TRUE);

   return(FALSE);
  }

/***************************************************/
/* ProcessConnectedConstraints: Examines a single  */
/*   connected constraint searching for constraint */
/*   violations.                                   */
/***************************************************/
globle intBool ProcessConnectedConstraints(
  void *theEnv,
  struct lhsParseNode *theNode,
  struct lhsParseNode *multifieldHeader,
  struct lhsParseNode *patternHead)
  {
   struct constraintRecord *orConstraints = NULL, *andConstraints;
   struct constraintRecord *tmpConstraints, *rvConstraints;
   struct lhsParseNode *orNode, *andNode;
   struct expr *tmpExpr;

   /*============================================*/
   /* Loop through all of the or (|) constraints */
   /* found in the connected constraint.         */
   /*============================================*/

   for (orNode = theNode->bottom; orNode != NULL; orNode = orNode->bottom)
     {
      /*=================================================*/
      /* Intersect all of the &'ed constraints together. */
      /*=================================================*/