modulutl.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 6.20  01/31/02            */
   /*                                                     */
   /*              DEFMODULE UTILITY MODULE               */
   /*******************************************************/

/*************************************************************/
/* Purpose: Provides routines for parsing module/construct   */
/*   names and searching through modules for specific        */
/*   constructs.                                             */
/*                                                           */
/* Principal Programmer(s):                                  */
/*      Gary D. Riley                                        */
/*                                                           */
/* Contributing Programmer(s):                               */
/*      Brian L. Donnell                                     */
/*                                                           */
/* Revision History:                                         */
/*                                                           */
/*************************************************************/

#define _MODULUTL_SOURCE_

#include "setup.h"

#include "memalloc.h"
#include "router.h"
#include "envrnmnt.h"

#include "modulpsr.h"
#include "modulutl.h"

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

   static void                      *SearchImportedConstructModules(void *,struct symbolHashNode *,
                                              struct defmodule *,
                                              struct moduleItem *,struct symbolHashNode *,
                                              int *,int,struct defmodule *);

/********************************************************************/
/* FindModuleSeparator: Finds the :: separator which delineates the */
/*   boundary between a module name and a construct name. The value */
/*   zero is returned if the separator is not found, otherwise the  */
/*   position of the second colon within the string is returned.    */
/********************************************************************/
globle unsigned FindModuleSeparator(
  char *theString)
  {
   unsigned i, foundColon;

   for (i = 0, foundColon = FALSE; theString[i] != EOS; i++)
     {
      if (theString[i] == ':')
        {
         if (foundColon) return(i);
         foundColon = TRUE;
        }
      else
        { foundColon = FALSE; }
     }

   return(FALSE);
  }

/*******************************************************************/
/* ExtractModuleName: Given the position of the :: separator and a */
/*   module/construct name joined using the separator, returns a   */
/*   symbol reference to the module name (or NULL if a module name */
/*   cannot be extracted).                                         */
/*******************************************************************/
globle SYMBOL_HN *ExtractModuleName(
  void *theEnv,
  unsigned thePosition,
  char *theString)
  {
   char *newString;
   SYMBOL_HN *returnValue;

   /*=============================================*/
   /* Return NULL if the :: is in a position such */
   /* that a module name can't be extracted.      */
   /*=============================================*/

   if (thePosition <= 1) return(NULL);

   /*==========================================*/
   /* Allocate storage for a temporary string. */
   /*==========================================*/

   newString = (char *) gm2(theEnv,thePosition);

   /*======================================================*/
   /* Copy the entire module/construct name to the string. */
   /*======================================================*/

   strncpy(newString,theString,
           (STD_SIZE) thePosition - 1);

   /*========================================================*/
   /* Place an end of string marker where the :: is located. */
   /*========================================================*/

   newString[thePosition-1] = EOS;

   /*=====================================================*/
   /* Add the module name (the truncated module/construct */
   /* name) to the symbol table.                          */
   /*=====================================================*/

   returnValue = (SYMBOL_HN *) EnvAddSymbol(theEnv,newString);

   /*=============================================*/
   /* Return the storage of the temporary string. */
   /*=============================================*/

   rm(theEnv,newString,thePosition);

   /*=============================================*/
   /* Return a pointer to the module name symbol. */
   /*=============================================*/

   return(returnValue);
  }

/********************************************************************/
/* ExtractConstructName: Given the position of the :: separator and */
/*   a module/construct name joined using the separator, returns a  */
/*   symbol reference to the construct name (or NULL if a construct */
/*   name cannot be extracted).                                     */
/********************************************************************/
globle SYMBOL_HN *ExtractConstructName(
  void *theEnv,
  unsigned thePosition,
  char *theString)
  {
   size_t theLength;
   char *newString;
   SYMBOL_HN *returnValue;

   /*======================================*/
   /* Just return the string if it doesn't */
   /* contain the :: symbol.               */
   /*======================================*/

   if (thePosition == 0) return((SYMBOL_HN *) EnvAddSymbol(theEnv,theString));

   /*=====================================*/
   /* Determine the length of the string. */
   /*=====================================*/

   theLength = strlen(theString);

   /*=================================================*/
   /* Return NULL if the :: is at the very end of the */
   /* string (and thus there is no construct name).   */
   /*=================================================*/

   if (theLength <= (thePosition + 1)) return(NULL);

   /*====================================*/
   /* Allocate a temporary string large  */
   /* enough to hold the construct name. */
   /*====================================*/

   newString = (char *) gm2(theEnv,theLength - thePosition);

   /*================================================*/
   /* Copy the construct name portion of the         */
   /* module/construct name to the temporary string. */
   /*================================================*/

   strncpy(newString,&theString[thePosition+1],
           (STD_SIZE) theLength - thePosition);

   /*=============================================*/
   /* Add the construct name to the symbol table. */
   /*=============================================*/

   returnValue = (SYMBOL_HN *) EnvAddSymbol(theEnv,newString);

   /*=============================================*/
   /* Return the storage of the temporary string. */
   /*=============================================*/

   rm(theEnv,newString,theLength - thePosition);

   /*================================================*/
   /* Return a pointer to the construct name symbol. */
   /*================================================*/

   return(returnValue);
  }

/****************************************************/
/* ExtractModuleAndConstructName: Extracts both the */
/*   module and construct name from a string. Sets  */
/*   the current module to the specified module.    */
/****************************************************/
globle char *ExtractModuleAndConstructName(
  void *theEnv,
  char *theName)
  {
   unsigned separatorPosition;
   SYMBOL_HN *moduleName, *shortName;
   struct defmodule *theModule;

   /*========================*/
   /* Find the :: separator. */
   /*========================*/

   separatorPosition = FindModuleSeparator(theName);
   if (! separatorPosition) return(theName);

   /*==========================*/
   /* Extract the module name. */
   /*==========================*/

   moduleName = ExtractModuleName(theEnv,separatorPosition,theName);
   if (moduleName == NULL) return(NULL);

   /*====================================*/
   /* Check to see if the module exists. */
   /*====================================*/

   theModule = (struct defmodule *) EnvFindDefmodule(theEnv,ValueToString(moduleName));
   if (theModule == NULL) return(NULL);

   /*============================*/
   /* Change the current module. */
   /*============================*/

   EnvSetCurrentModule(theEnv,(void *) theModule);

   /*=============================*/
   /* Extract the construct name. */
   /*=============================*/

   shortName = ExtractConstructName(theEnv,separatorPosition,theName);
   return(ValueToString(shortName));
  }

/************************************************************/
/* FindImportedConstruct: High level routine which searches */
/*   a module and other modules from which it imports       */
/*   constructs for a specified construct.                  */
/************************************************************/
globle void *FindImportedConstruct(
  void *theEnv,
  char *constructName,
  struct defmodule *matchModule,
  char *findName,
  int *count,
  int searchCurrent,
  struct defmodule *notYetDefinedInModule)
  {
   void *rv;
   struct moduleItem *theModuleItem;

   /*=============================================*/
   /* Set the number of references found to zero. */
   /*=============================================*/

   *count = 0;

   /*===============================*/
   /* The :: should not be included */
   /* in the construct's name.      */
   /*===============================*/

   if (FindModuleSeparator(findName)) return(NULL);

   /*=============================================*/
   /* Remember the current module since we'll be  */
   /* changing it during the search and will want */
   /* to restore it once the search is completed. */
   /*=============================================*/

   SaveCurrentModule(theEnv);

   /*==========================================*/
   /* Find the module related access functions */
   /* for the construct type being sought.     */
   /*==========================================*/

   if ((theModuleItem = FindModuleItem(theEnv,constructName)) == NULL)
     {
      RestoreCurrentModule(theEnv);
      return(NULL);
     }

   /*===========================================*/
   /* If the construct type doesn't have a find */
   /* function, then we can't look for it.      */
   /*===========================================*/

   if (theModuleItem->findFunction == NULL)
     {
      RestoreCurrentModule(theEnv);
      return(NULL);
     }

   /*==================================*/
   /* Initialize the search by marking */
   /* all modules as unvisited.        */
   /*==================================*/

   MarkModulesAsUnvisited(theEnv);

   /*===========================*/
   /* Search for the construct. */
   /*===========================*/

   rv = SearchImportedConstructModules(theEnv,(SYMBOL_HN *) EnvAddSymbol(theEnv,constructName),
                                       matchModule,theModuleItem,
                                       (SYMBOL_HN *) EnvAddSymbol(theEnv,findName),count,
                                       searchCurrent,notYetDefinedInModule);

   /*=============================*/
   /* Restore the current module. */
   /*=============================*/

   RestoreCurrentModule(theEnv);

   /*====================================*/
   /* Return a pointer to the construct. */
   /*====================================*/

   return(rv);
  }

/*********************************************************/
/* AmbiguousReferenceErrorMessage: Error message printed */
/*   when a reference to a specific construct can be     */
/*   imported from more than one module.                 */
/*********************************************************/
globle void AmbiguousReferenceErrorMessage(
  void *theEnv,