reorder.c

VC嵌入式CLips专家系统,实现战场环境的目标识别

   /*******************************************************/
   /*      "C" Language Integrated Production System      */
   /*                                                     */
   /*             CLIPS Version 6.21  06/15/03            */
   /*                                                     */
   /*                    REORDER MODULE                   */
   /*******************************************************/

/*************************************************************/
/* Purpose: Provides routines necessary for converting the   */
/*   the LHS of a rule into an appropriate form suitable for */
/*   the KB Rete topology. This includes transforming the    */
/*   LHS so there is at most one "or" CE (and this is the    */
/*   first CE of the LHS if it is used), adding initial      */
/*   patterns to the LHS (if no LHS is specified or a "test" */
/*   or "not" CE is the first pattern within an "and" CE),   */
/*   removing redundant CEs, and determining appropriate     */
/*   information on nesting for implementing joins from the  */
/*   right.                                                  */
/*                                                           */
/* Principal Programmer(s):                                  */
/*      Gary D. Riley                                        */
/*                                                           */
/* Contributing Programmer(s):                               */
/*                                                           */
/* Revision History:                                         */
/*                                                           */
/*************************************************************/

#define _REORDER_SOURCE_

#include "setup.h"

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

#include <stdio.h>
#define _STDIO_INCLUDED_

#include "cstrnutl.h"
#include "envrnmnt.h"
#include "extnfunc.h"
#include "memalloc.h"
#include "pattern.h"
#include "prntutil.h"
#include "router.h"
#include "rulelhs.h"

#include "reorder.h"

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

   static struct lhsParseNode    *ReverseAndOr(void *,struct lhsParseNode *,struct lhsParseNode *,int);
   static struct lhsParseNode    *PerformReorder1(void *,struct lhsParseNode *,int *);
   static struct lhsParseNode    *PerformReorder2(void *,struct lhsParseNode *,int *);
   static struct lhsParseNode    *CompressCEs(void *,struct lhsParseNode *,int *);
   static void                    IncrementNandDepth(void *,struct lhsParseNode *,int);
   static struct lhsParseNode    *CreateInitialPattern(void *,struct patternParser *);
   static struct lhsParseNode    *ReorderDriver(void *,struct lhsParseNode *,int *,int);
   static void                    AddRemainingInitialPatterns(void *,struct lhsParseNode *,struct patternParser *);
   static void                    PrintNodes(void *,char *,struct lhsParseNode *);
   static struct lhsParseNode    *AssignPatternIndices(struct lhsParseNode *,short);
   static void                    PropagateIndexSlotPatternValues(struct lhsParseNode *,
                                                                  short,short,
                                                                  struct symbolHashNode *,
                                                                  short);

/********************************************/
/* ReorderPatterns: Reorders a group of CEs */
/*   to accommodate KB Rete topology.       */
/********************************************/
globle struct lhsParseNode *ReorderPatterns(
  void *theEnv,
  struct lhsParseNode *theLHS,
  int *anyChange)
  {
   struct lhsParseNode *newLHS, *patternPtr, *tempLHS, *lastLHS;
   unsigned int whichCE;

   /*===========================================================*/
   /* The LHS of a rule is enclosed within an implied "and" CE. */
   /*===========================================================*/

   newLHS = GetLHSParseNode(theEnv);
   newLHS->type = AND_CE;

   /*=============================================*/
   /* If the LHS of the rule was left unspecified */
   /* (e.g., (defrule x => ...)), then add an     */
   /* initial fact or instance pattern to the LHS */
   /* of the rule. Otherwise, attach the user     */
   /* specified LHS to the implied "and" Ce.      */
   /*=============================================*/

   if (theLHS == NULL) newLHS->right = CreateInitialPattern(theEnv,NULL);
   else newLHS->right = theLHS;

   /*=======================================================*/
   /* Reorder the patterns to support the KB Rete topology. */
   /*=======================================================*/

   newLHS = ReorderDriver(theEnv,newLHS,anyChange,1);
   newLHS = ReorderDriver(theEnv,newLHS,anyChange,2);

   /*===========================================*/
   /* The top level and CE may have disappeared */
   /* as a result of pattern compression.       */
   /*===========================================*/

   if (newLHS->type == OR_CE)
     {
      for (tempLHS = newLHS->right, lastLHS = NULL;
           tempLHS != NULL;
           lastLHS = tempLHS, tempLHS = tempLHS->bottom)
        {
         if (tempLHS->type != AND_CE)
           {
            theLHS = GetLHSParseNode(theEnv);
            theLHS->type = AND_CE;
            theLHS->right = tempLHS;
            theLHS->bottom = tempLHS->bottom;
            tempLHS->bottom = NULL;
            if (lastLHS == NULL)
              { newLHS->right = theLHS; }
            else
              { lastLHS->bottom = theLHS; }
            tempLHS = theLHS;
           }
        }
     }
   else if (newLHS->type != AND_CE)
     {
      theLHS = newLHS;
      newLHS = GetLHSParseNode(theEnv);
      newLHS->type = AND_CE;
      newLHS->right = theLHS;
     }

   /*=====================================================*/
   /* Add initial patterns where needed (such as before a */
   /* "test" CE or "not" CE which is the first CE within  */
   /* an "and" CE).                                       */
   /*=====================================================*/

   AddInitialPatterns(theEnv,newLHS);

   /*===========================================================*/
   /* Number the user specified patterns. Patterns added while  */
   /* analyzing the rule (such as placing initial-fact patterns */
   /* before not CEs) are not numbered so that there is no      */
   /* confusion when an error message refers to a CE. Also      */
   /* propagate field and slot values throughout each pattern.  */
   /*===========================================================*/

   if (newLHS->type == OR_CE) theLHS = newLHS->right;
   else theLHS = newLHS;

   for (;
        theLHS != NULL;
        theLHS = theLHS->bottom)
     {
      whichCE = 1;
      for (patternPtr = theLHS->right;
           patternPtr != NULL;
           patternPtr = patternPtr->bottom)
        { if (patternPtr->userCE) patternPtr->whichCE = whichCE++; }

      AssignPatternIndices(theLHS->right,1);
     }

   /*===========================*/
   /* Return the processed LHS. */
   /*===========================*/

   return(newLHS);
  }

/******************************************/
/* ReorderDriver: Reorders a group of CEs */
/*   to accommodate KB Rete topology.     */
/******************************************/
static struct lhsParseNode *ReorderDriver(
  void *theEnv,
  struct lhsParseNode *theLHS,
  int *anyChange,
  int pass)
  {
   struct lhsParseNode *argPtr;
   struct lhsParseNode *before, *save;
   int change, newChange;
   *anyChange = FALSE;

   /*===================================*/
   /* Continue processing the LHS until */
   /* no more changes have been made.   */
   /*===================================*/

   change = TRUE;
   while (change)
     {
      /*==================================*/
      /* No change yet on this iteration. */
      /*==================================*/

      change = FALSE;

      /*=======================================*/
      /* Reorder the current level of the LHS. */
      /*=======================================*/

      if ((theLHS->type == AND_CE) ||
          (theLHS->type == NOT_CE) ||
          (theLHS->type == OR_CE))
        {
         if (pass == 1) theLHS = PerformReorder1(theEnv,theLHS,&newChange);
         else theLHS = PerformReorder2(theEnv,theLHS,&newChange);

         if (newChange)
           {
            *anyChange = TRUE;
            change = TRUE;
           }

         theLHS = CompressCEs(theEnv,theLHS,&newChange);

         if (newChange)
           {
            *anyChange = TRUE;
            change = TRUE;
           }
        }

      /*=====================================================*/
      /* Recursively reorder CEs at lower levels in the LHS. */
      /*=====================================================*/

      before = NULL;
      argPtr = theLHS->right;

      while (argPtr != NULL)
        {
         /*==================================*/
         /* Remember the next CE to reorder. */
         /*==================================*/

         save = argPtr->bottom;

         /*============================================*/
         /* Reorder the current CE at the lower level. */
         /*============================================*/

         if ((argPtr->type == AND_CE) ||
             (argPtr->type == NOT_CE) ||
             (argPtr->type == OR_CE))
           {
            if (before == NULL)
              {
               argPtr->bottom = NULL;
               theLHS->right = ReorderDriver(theEnv,argPtr,&newChange,pass);
               theLHS->right->bottom = save;
               before = theLHS->right;
              }
            else
              {
               argPtr->bottom = NULL;
               before->bottom = ReorderDriver(theEnv,argPtr,&newChange,pass);
               before->bottom->bottom = save;
               before = before->bottom;
              }

            if (newChange)
              {
               *anyChange = TRUE;
               change = TRUE;
              }
           }
         else
           { before = argPtr; }

         /*====================================*/
         /* Move on to the next CE to reorder. */
         /*====================================*/

         argPtr = save;
        }
     }

   /*===========================*/
   /* Return the reordered LHS. */
   /*===========================*/

   return(theLHS);
  }

/****************************************************************/
/* AddInitialPatterns: Add initial patterns to CEs where needed */
/*   (such as before a "test" CE or "not" CE which is the first */
/*   CE within an "and" CE).                                    */
/****************************************************************/
globle void AddInitialPatterns(
  void *theEnv,
  struct lhsParseNode *theLHS)
  {
   struct lhsParseNode *thePattern;
   struct patternParser *lastType;

   /*====================================================*/
   /* If there are multiple disjuncts for the rule, then */
   /* add initial patterns to each disjunct separately.  */
   /*====================================================*/

   if (theLHS->type == OR_CE)
     {
      for (thePattern = theLHS->right;
           thePattern != NULL;
           thePattern = thePattern->bottom)
        { AddInitialPatterns(theEnv,thePattern); }

      return;
     }

   /*======================================================*/
   /* Determine what the default pattern type for the rule */
   /* should be (in case the rule begins with a test CE).  */
   /* The default pattern type is the type of the data     */
   /* entity associated with the first pattern CE found in */
   /* the LHS of the rule.                                 */
   /*======================================================*/

   for (lastType = NULL, thePattern = theLHS->right;
        thePattern != NULL;
        thePattern = thePattern->bottom)
     {
      if (thePattern->type == PATTERN_CE)
        {
         lastType = thePattern->patternType;
         break;
        }
     }

   /*===================================================*/
   /* Add an initial pattern to the first CE of a rule  */
   /* if the CE is a "test" CE, "not" CE or a join from */
   /* the right.                                        */
   /*===================================================*/

   if ((theLHS->right->negated) ||
       (theLHS->right->type == TEST_CE) ||
       (theLHS->right->beginNandDepth > 1))
     {
      thePattern = CreateInitialPattern(theEnv,lastType);

      thePattern->logical = (theLHS->logical || theLHS->right->logical);
      thePattern->bottom = theLHS->right;
      theLHS->right = thePattern;
     }

   /*================================*/
   /* Handle the remaining patterns. */
   /*================================*/

   AddRemainingInitialPatterns(theEnv,theLHS->right,lastType);
  }

/***********************************************************/
/* PerformReorder1: Reorders a group of CEs to accommodate */
/*   KB Rete topology. The first pass of this function     */
/*   transforms or CEs into equivalent forms.              */
/***********************************************************/
static struct lhsParseNode *PerformReorder1(
  void *theEnv,
  struct lhsParseNode *theLHS,
  int *newChange)
  {
   struct lhsParseNode *argPtr, *lastArg, *nextArg;
   struct lhsParseNode *tempArg, *newNode;
   int count;
   int change;

   /*======================================================*/
   /* Loop through the CEs as long as changes can be made. */
   /*======================================================*/

   change = TRUE;
   *newChange = FALSE;

   while (change)
     {
      change = FALSE;
      count = 1;
      lastArg = NULL;

      for (argPtr = theLHS->right;