tmpltrhs.c

NASA 开发使用的一个专家系统

   /*******************************************************/
   /*      "C" Language Integrated Production System      */
   /*                                                     */
   /*             CLIPS Version 6.05  04/09/97            */
   /*                                                     */
   /*          DEFTEMPLATE RHS PARSING HEADER FILE        */
   /*******************************************************/

/*************************************************************/
/* Purpose: Parses deftemplate fact patterns used with the   */
/*   assert function.                                        */
/*                                                           */
/* Principal Programmer(s):                                  */
/*      Gary D. Riley                                        */
/*                                                           */
/* Contributing Programmer(s):                               */
/*                                                           */
/* Revision History:                                         */
/*                                                           */
/*************************************************************/

#define _TMPLTRHS_SOURCE_

#include "setup.h"

#if DEFTEMPLATE_CONSTRUCT

#include <stdio.h>
#define _CLIPS_STDIO_

#include "clipsmem.h"
#include "prntutil.h"
#include "router.h"
#include "tmpltfun.h"
#include "tmpltdef.h"
#include "factrhs.h"
#include "extnfunc.h"
#include "modulutl.h"
#include "default.h"
#include "tmpltutl.h"
#include "tmpltlhs.h"

#include "tmpltrhs.h"

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

#if ANSI_COMPILER
   static struct expr            *ParseAssertSlotValues(char *,struct token *,struct templateSlot *,int *,int);
   static struct expr            *ReorderAssertSlotValues(struct templateSlot *,struct expr *,int *);
   static struct expr            *GetSlotAssertValues(struct templateSlot *,struct expr *,int *);
   static struct expr            *FindAssertSlotItem(struct templateSlot *,struct expr *);
   static struct templateSlot    *ParseSlotLabel(char *,struct token *,struct deftemplate *,int *,int);
#else
   static struct expr            *ParseAssertSlotValues();
   static struct expr            *ReorderAssertSlotValues();
   static struct expr            *GetSlotAssertValues();
   static struct expr            *FindAssertSlotItem();
   static struct templateSlot    *ParseSlotLabel();
#endif

/******************************************************************/
/* ParseAssertTemplate: Parses and builds the list of values that */
/*   are used for an assert of a fact with a deftemplate.         */
/******************************************************************/
globle struct expr *ParseAssertTemplate(readSource,theToken,error,endType,
                                        constantsOnly,theDeftemplate)
  char *readSource;
  struct token *theToken;
  int *error;
  int endType, constantsOnly;
  struct deftemplate *theDeftemplate;
  {
   struct expr *firstSlot, *lastSlot, *nextSlot;
   struct expr *firstArg, *tempSlot;
   struct templateSlot *slotPtr;

   firstSlot = NULL;
   lastSlot = NULL;

   /*==============================================*/
   /* Parse each of the slot fields in the assert. */
   /*==============================================*/

   while ((slotPtr = ParseSlotLabel(readSource,theToken,theDeftemplate,error,endType)) != NULL)
     {
      /*========================================================*/
      /* Check to see that the slot hasn't already been parsed. */
      /*========================================================*/
      
      for (tempSlot = firstSlot; 
           tempSlot != NULL;
           tempSlot = tempSlot->nextArg)
        {
         if (tempSlot->value == (VOID *) slotPtr->slotName)
           {        
            AlreadyParsedErrorMessage("slot ",ValueToString(slotPtr->slotName));
            *error = CLIPS_TRUE;
            ReturnExpression(firstSlot);
            return(NULL);
           }
        }
        
      /*============================================*/
      /* Parse the values to be stored in the slot. */
      /*============================================*/
      
      nextSlot = ParseAssertSlotValues(readSource,theToken,
                                       slotPtr,error,constantsOnly);

      if (*error)
        {
         ReturnExpression(firstSlot);
         return(NULL);
        }

      /*============================================*/
      /* Check to see if the values to be stored in */
      /* the slot violate the slot's constraints.   */
      /*============================================*/
      
      if (CheckRHSSlotTypes(nextSlot->argList,slotPtr,"assert") == 0)
        {
         *error = CLIPS_TRUE;
         ReturnExpression(firstSlot);
         ReturnExpression(nextSlot);
         return(NULL);
        }

      /*===================================================*/
      /* Add the slot to the list of slots already parsed. */
      /*===================================================*/
      
      if (lastSlot == NULL)
        { firstSlot = nextSlot; }
      else
        { lastSlot->nextArg = nextSlot; }
        
      lastSlot = nextSlot;
     }

   /*=================================================*/
   /* Return if an error occured parsing a slot name. */
   /*=================================================*/
   
   if (*error)
     {
      ReturnExpression(firstSlot);
      return(NULL);
     }

   /*=============================================================*/
   /* Reorder the arguments to the order used by the deftemplate. */
   /*=============================================================*/

   firstArg = ReorderAssertSlotValues(theDeftemplate->slotList,firstSlot,error);
   ReturnExpression(firstSlot);

   /*==============================*/
   /* Return the assert arguments. */
   /*==============================*/

   return(firstArg);
  }
     
/****************************************************************/
/* ParseSlotLabel: Parses the beginning of a slot definition.   */
/*   Checks for opening left parenthesis and a valid slot name. */
/****************************************************************/
static struct templateSlot *ParseSlotLabel(inputSource,tempToken,theDeftemplate,error,endType)
  char *inputSource;
  struct token *tempToken;
  struct deftemplate *theDeftemplate;
  int *error;
  int endType;
  {
   struct templateSlot *slotPtr;
   int position;

   /*========================*/
   /* Initialize error flag. */
   /*========================*/

   *error = CLIPS_FALSE;

   /*============================================*/
   /* If token is a right parenthesis, then fact */
   /* template definition is complete.           */
   /*============================================*/

   GetToken(inputSource,tempToken);
   if (tempToken->type == endType)
     { return(NULL); }

   /*=======================================*/
   /* Put a space between the template name */
   /* and the first slot definition.        */
   /*=======================================*/

   PPBackup();
   SavePPBuffer(" ");
   SavePPBuffer(tempToken->printForm);

   /*=======================================================*/
   /* Slot definition begins with opening left parenthesis. */
   /*=======================================================*/

   if (tempToken->type != LPAREN)
     {
      SyntaxErrorMessage("deftemplate pattern");
      *error = CLIPS_TRUE;
      return(NULL);
     }

   /*=============================*/
   /* Slot name must be a symbol. */
   /*=============================*/

   GetToken(inputSource,tempToken);
   if (tempToken->type != SYMBOL)
     {
      SyntaxErrorMessage("deftemplate pattern");
      *error = CLIPS_TRUE;
      return(NULL);
     }

   /*======================================================*/
   /* Check that the slot name is valid for this template. */
   /*======================================================*/

   if ((slotPtr = FindSlot(theDeftemplate,tempToken->value,&position)) == NULL)
     {
      InvalidDeftemplateSlotMessage(ValueToString(tempToken->value),
                                    ValueToString(theDeftemplate->header.name));
      *error = CLIPS_TRUE;
      return(NULL);
     }

   /*====================================*/
   /* Return a pointer to the slot name. */
   /*====================================*/

   return(slotPtr);
  }

/**************************************************************************/
/* ParseAssertSlotValues: Gets a single assert slot value for a template. */
/**************************************************************************/
static struct expr *ParseAssertSlotValues(inputSource,tempToken,
                                          slotPtr,error,constantsOnly)
  char *inputSource;
  struct token *tempToken;
  struct templateSlot *slotPtr;
  int *error;
  int constantsOnly;
  {
   struct expr *nextSlot;
   struct expr *newField, *valueList, *lastValue;
   int printError;

   /*=============================*/
   /* Handle a single field slot. */
   /*=============================*/

   if (slotPtr->multislot == CLIPS_FALSE)
     {
      /*=====================*/
      /* Get the slot value. */
      /*=====================*/
      
      SavePPBuffer(" ");
      
      newField = GetAssertArgument(inputSource,tempToken,
                                   error,RPAREN,constantsOnly,&printError);
      if (*error)
        {
         if (printError) SyntaxErrorMessage("deftemplate pattern");
         return(NULL);
        }

      /*=================================================*/
      /* A single field slot value must contain a value. */
      /* Only a multifield slot can be empty.            */