strngfun.c

clips源代码

   if (EnvArgTypeCheck(theEnv,"eval",1,SYMBOL_OR_STRING,&theArg) == FALSE)
     {
      SetpType(returnValue,SYMBOL);
      SetpValue(returnValue,EnvFalseSymbol(theEnv));
      return;
     }

   /*======================*/
   /* Evaluate the string. */
   /*======================*/

   EnvEval(theEnv,DOToString(theArg),returnValue);
  }

/*****************************/
/* EnvEval: C access routine */
/*   for the eval function.  */
/*****************************/
globle int EnvEval(
  void *theEnv,
  char *theString,
  DATA_OBJECT_PTR returnValue)
  {
   struct expr *top;
   int ov;
   static int depth = 0;
   char logicalNameBuffer[20];
   struct BindInfo *oldBinds;

   /*======================================================*/
   /* Evaluate the string. Create a different logical name */
   /* for use each time the eval function is called.       */
   /*======================================================*/

   depth++;
   gensprintf(logicalNameBuffer,"Eval-%d",depth);
   if (OpenStringSource(theEnv,logicalNameBuffer,theString,0) == 0)
     {
      SetpType(returnValue,SYMBOL);
      SetpValue(returnValue,EnvFalseSymbol(theEnv));
      depth--;
      return(FALSE);
     }

   /*================================================*/
   /* Save the current parsing state before routines */
   /* are called to parse the eval string.           */
   /*================================================*/

   ov = GetPPBufferStatus(theEnv);
   SetPPBufferStatus(theEnv,FALSE);
   oldBinds = GetParsedBindNames(theEnv);
   SetParsedBindNames(theEnv,NULL);

   /*========================================================*/
   /* Parse the string argument passed to the eval function. */
   /*========================================================*/

   top = ParseAtomOrExpression(theEnv,logicalNameBuffer,NULL);

   /*============================*/
   /* Restore the parsing state. */
   /*============================*/

   SetPPBufferStatus(theEnv,ov);
   ClearParsedBindNames(theEnv);
   SetParsedBindNames(theEnv,oldBinds);

   /*===========================================*/
   /* Return if an error occured while parsing. */
   /*===========================================*/

   if (top == NULL)
     {
      SetEvaluationError(theEnv,TRUE);
      CloseStringSource(theEnv,logicalNameBuffer);
      SetpType(returnValue,SYMBOL);
      SetpValue(returnValue,EnvFalseSymbol(theEnv));
      depth--;
      return(FALSE);
     }

   /*==============================================*/
   /* The sequence expansion operator must be used */
   /* within the argument list of a function call. */
   /*==============================================*/

   if ((top->type == MF_GBL_VARIABLE) || (top->type == MF_VARIABLE))
     {
      PrintErrorID(theEnv,"MISCFUN",1,FALSE);
      EnvPrintRouter(theEnv,WERROR,"expand$ must be used in the argument list of a function call.\n");
      SetEvaluationError(theEnv,TRUE);
      CloseStringSource(theEnv,logicalNameBuffer);
      SetpType(returnValue,SYMBOL);
      SetpValue(returnValue,EnvFalseSymbol(theEnv));
      ReturnExpression(theEnv,top);
      depth--;
      return(FALSE);
     }

   /*=======================================*/
   /* The expression to be evaluated cannot */
   /* contain any local variables.          */
   /*=======================================*/

   if (ExpressionContainsVariables(top,FALSE))
     {
      PrintErrorID(theEnv,"STRNGFUN",2,FALSE);
      EnvPrintRouter(theEnv,WERROR,"Some variables could not be accessed by the eval function.\n");
      SetEvaluationError(theEnv,TRUE);
      CloseStringSource(theEnv,logicalNameBuffer);
      SetpType(returnValue,SYMBOL);
      SetpValue(returnValue,EnvFalseSymbol(theEnv));
      ReturnExpression(theEnv,top);
      depth--;
      return(FALSE);
     }

   /*====================================*/
   /* Evaluate the expression and return */
   /* the memory used to parse it.       */
   /*====================================*/

   ExpressionInstall(theEnv,top);
   EvaluateExpression(theEnv,top,returnValue);
   ExpressionDeinstall(theEnv,top);

   depth--;
   ReturnExpression(theEnv,top);
   CloseStringSource(theEnv,logicalNameBuffer);

   /*==========================================*/
   /* Perform periodic cleanup if the eval was */
   /* issued from an embedded controller.      */
   /*==========================================*/

   if ((EvaluationData(theEnv)->CurrentEvaluationDepth == 0) && (! CommandLineData(theEnv)->EvaluatingTopLevelCommand) &&
       (EvaluationData(theEnv)->CurrentExpression == NULL))
     { 
      ValueInstall(theEnv,returnValue);
      PeriodicCleanup(theEnv,TRUE,FALSE); 
      ValueDeinstall(theEnv,returnValue);
     }

   if (GetEvaluationError(theEnv)) return(FALSE);
   return(TRUE);
  }

#else

/*************************************************/
/* EvalFunction: This is the non-functional stub */
/*   provided for use with a run-time version.   */
/*************************************************/
globle void EvalFunction(
  void *theEnv,
  DATA_OBJECT_PTR returnValue)
  {
   PrintErrorID(theEnv,"STRNGFUN",1,FALSE);
   EnvPrintRouter(theEnv,WERROR,"Function eval does not work in run time modules.\n");
   SetpType(returnValue,SYMBOL);
   SetpValue(returnValue,EnvFalseSymbol(theEnv));
  }

/*****************************************************/
/* EnvEval: This is the non-functional stub provided */
/*   for use with a run-time version.                */
/*****************************************************/
globle int EnvEval(
  void *theEnv,
  char *theString,
  DATA_OBJECT_PTR returnValue)
  {
#if (MAC_MCW || IBM_MCW) && (RUN_TIME || BLOAD_ONLY)
#pragma unused(theString)
#endif

   PrintErrorID(theEnv,"STRNGFUN",1,FALSE);
   EnvPrintRouter(theEnv,WERROR,"Function eval does not work in run time modules.\n");
   SetpType(returnValue,SYMBOL);
   SetpValue(returnValue,EnvFalseSymbol(theEnv));
   return(FALSE);
  }

#endif

#if (! RUN_TIME) && (! BLOAD_ONLY)
/***************************************/
/* BuildFunction: H/L access routine   */
/*   for the build function.           */
/***************************************/
globle int BuildFunction(
  void *theEnv)
  {
   DATA_OBJECT theArg;

   /*==============================================*/
   /* Function build expects exactly one argument. */
   /*==============================================*/

   if (EnvArgCountCheck(theEnv,"build",EXACTLY,1) == -1) return(FALSE);

   /*==================================================*/
   /* The argument should be of type SYMBOL or STRING. */
   /*==================================================*/

   if (EnvArgTypeCheck(theEnv,"build",1,SYMBOL_OR_STRING,&theArg) == FALSE)
     { return(FALSE); }

   /*======================*/
   /* Build the construct. */
   /*======================*/

   return(EnvBuild(theEnv,DOToString(theArg)));
  }

/******************************/
/* EnvBuild: C access routine */
/*   for the build function.  */
/******************************/
globle int EnvBuild(
  void *theEnv,
  char *theString)
  {
   char *constructType;
   struct token theToken;
   int errorFlag;

   /*====================================================*/
   /* No additions during defrule join network activity. */
   /*====================================================*/

#if DEFRULE_CONSTRUCT
   if (EngineData(theEnv)->JoinOperationInProgress) return(FALSE);
#endif

   /*===========================================*/
   /* Create a string source router so that the */
   /* string can be used as an input source.    */
   /*===========================================*/

   if (OpenStringSource(theEnv,"build",theString,0) == 0)
     { return(FALSE); }

   /*================================*/
   /* The first token of a construct */
   /* must be a left parenthesis.    */
   /*================================*/

   GetToken(theEnv,"build",&theToken);

   if (theToken.type != LPAREN)
     {
      CloseStringSource(theEnv,"build");
      return(FALSE);
     }

   /*==============================================*/
   /* The next token should be the construct type. */
   /*==============================================*/

   GetToken(theEnv,"build",&theToken);
   if (theToken.type != SYMBOL)
     {
      CloseStringSource(theEnv,"build");
      return(FALSE);
     }

   constructType = ValueToString(theToken.value);

   /*======================*/
   /* Parse the construct. */
   /*======================*/
   
   errorFlag = ParseConstruct(theEnv,constructType,"build");

   /*=================================*/
   /* Close the string source router. */
   /*=================================*/

   CloseStringSource(theEnv,"build");

   /*=========================================*/
   /* If an error occured while parsing the   */
   /* construct, then print an error message. */
   /*=========================================*/

   if (errorFlag == 1)
     {
      EnvPrintRouter(theEnv,WERROR,"\nERROR:\n");
      PrintInChunks(theEnv,WERROR,GetPPBuffer(theEnv));
      EnvPrintRouter(theEnv,WERROR,"\n");
     }

   DestroyPPBuffer(theEnv);

   /*===========================================*/
   /* Perform periodic cleanup if the build was */
   /* issued from an embedded controller.       */
   /*===========================================*/

   if ((EvaluationData(theEnv)->CurrentEvaluationDepth == 0) && (! CommandLineData(theEnv)->EvaluatingTopLevelCommand) &&
       (EvaluationData(theEnv)->CurrentExpression == NULL))
     { PeriodicCleanup(theEnv,TRUE,FALSE); }

   /*===============================================*/
   /* Return TRUE if the construct was successfully */
   /* parsed, otherwise return FALSE.               */
   /*===============================================*/

   if (errorFlag == 0) return(TRUE);

   return(FALSE);
  }
#else
/**************************************************/
/* BuildFunction: This is the non-functional stub */
/*   provided for use with a run-time version.    */
/**************************************************/
globle int BuildFunction(
  void *theEnv)
  {
   PrintErrorID(theEnv,"STRNGFUN",1,FALSE);
   EnvPrintRouter(theEnv,WERROR,"Function build does not work in run time modules.\n");
   return(FALSE);
  }

/******************************************************/
/* EnvBuild: This is the non-functional stub provided */
/*   for use with a run-time version.                 */
/******************************************************/
globle int EnvBuild(
  void *theEnv,
  char *theString)
  { 
#if (MAC_MCW || IBM_MCW) && (RUN_TIME || BLOAD_ONLY)
#pragma unused(theString)
#endif

   PrintErrorID(theEnv,"STRNGFUN",1,FALSE);
   EnvPrintRouter(theEnv,WERROR,"Function build does not work in run time modules.\n");
   return(FALSE);
  }
#endif /* (! RUN_TIME) && (! BLOAD_ONLY) */

#endif /* STRING_FUNCTIONS */