globlpsr.c

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   /*******************************************************/
   /*      "C" Language Integrated Production System      */
   /*                                                     */
   /*             CLIPS Version 6.05  04/09/97            */
   /*                                                     */
   /*              DEFGLOBAL PARSER MODULE                */
   /*******************************************************/

/*************************************************************/
/* Purpose: Parses the defglobal construct.                  */
/*                                                           */
/* Principal Programmer(s):                                  */
/*      Gary D. Riley                                        */
/*                                                           */
/* Contributing Programmer(s):                               */
/*      Brian L. Donnell                                     */
/*                                                           */
/* Revision History:                                         */
/*                                                           */
/*************************************************************/

#define _GLOBLPSR_SOURCE_

#include "setup.h"

#if DEFGLOBAL_CONSTRUCT

#include <string.h>

#include "pprint.h"
#include "router.h"
#include "clipsmem.h"
#include "scanner.h"
#include "evaluatn.h"
#include "exprnpsr.h"
#include "constrct.h"
#include "multifld.h"
#include "watch.h"
#include "modulutl.h"
#include "modulpsr.h"
#include "cstrcpsr.h"
#include "globldef.h"
#include "globlbsc.h"

#if BLOAD || BLOAD_ONLY || BLOAD_AND_BSAVE
#include "bload.h"
#endif

#include "globlpsr.h"

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

#if (! RUN_TIME) && (! BLOAD_ONLY)
#if ANSI_COMPILER
   static BOOLEAN                 GetVariableDefinition(char *,int *,int,struct token *);
   static VOID                    AddDefglobal(SYMBOL_HN *,DATA_OBJECT_PTR,struct expr *);
#else
   static BOOLEAN                 GetVariableDefinition();
   static VOID                    AddDefglobal();
#endif
#endif

/*********************************************************************/
/* ParseDefglobal: Coordinates all actions necessary for the parsing */
/*   and creation of a defglobal into the current environment.       */
/*********************************************************************/
globle BOOLEAN ParseDefglobal(readSource)
  char *readSource;
  {
   int defglobalError = CLIPS_FALSE;
#if (MAC_MPW || MAC_MCW) && (RUN_TIME || BLOAD_ONLY)
#pragma unused(readSource)
#endif
   
#if (! RUN_TIME) && (! BLOAD_ONLY)

   struct token theToken;
   int tokenRead = CLIPS_TRUE;
   struct defmodule *theModule;

   /*=====================================*/
   /* Pretty print buffer initialization. */
   /*=====================================*/
   
   SetPPBufferStatus(ON);
   FlushPPBuffer();
   SetIndentDepth(3);
   SavePPBuffer("(defglobal ");

   /*=================================================*/
   /* Individual defglobal constructs can't be parsed */
   /* while a binary load is in effect.               */
   /*=================================================*/
   
#if BLOAD || BLOAD_ONLY || BLOAD_AND_BSAVE
   if (Bloaded() == CLIPS_TRUE)
     {
      CannotLoadWithBloadMessage("defglobal");
      return(CLIPS_TRUE);
     }
#endif

   /*===========================*/
   /* Look for the module name. */
   /*===========================*/
   
   GetToken(readSource,&theToken);
   if (theToken.type == SYMBOL)
     {
      /*=================================================*/
      /* The optional module name can't contain a module */
      /* separator like other constructs. For example,   */
      /* (defrule X::foo is OK for rules, but the right  */
      /* syntax for defglobals is (defglobal X ?*foo*.   */
      /*=================================================*/
      
      tokenRead = CLIPS_FALSE;
      if (FindModuleSeparator(ValueToString(theToken.value)))
        {
         SyntaxErrorMessage("defglobal");
         return(CLIPS_TRUE);
        }      
      
      /*=================================*/
      /* Determine if the module exists. */
      /*=================================*/
      
      theModule = (struct defmodule *) FindDefmodule(ValueToString(theToken.value));
      if (theModule == NULL)
        {
         CantFindItemErrorMessage("defmodule",ValueToString(theToken.value));
         return(CLIPS_TRUE);
        }
        
      /*=========================================*/
      /* If the module name was OK, then set the */
      /* current module to the specified module. */
      /*=========================================*/
      
      SavePPBuffer(" ");
      SetCurrentModule((VOID *) theModule);
     }
     
   /*===========================================*/
   /* If the module name wasn't specified, then */
   /* use the current module's name in the      */
   /* defglobal's pretty print representation.  */
   /*===========================================*/
   
   else
     { 
      PPBackup();
      SavePPBuffer(GetDefmoduleName(((struct defmodule *) GetCurrentModule())));
      SavePPBuffer(" ");
      SavePPBuffer(theToken.printForm);
     }

   /*======================*/
   /* Parse the variables. */
   /*======================*/

   while (GetVariableDefinition(readSource,&defglobalError,tokenRead,&theToken))
     { 
      tokenRead = CLIPS_FALSE;
      
      FlushPPBuffer();
      SavePPBuffer("(defglobal ");
      SavePPBuffer(GetDefmoduleName(((struct defmodule *) GetCurrentModule())));
      SavePPBuffer(" ");
     }

#endif

   /*==================================*/
   /* Return the parsing error status. */
   /*==================================*/
   
   return(defglobalError);
  }

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

/***************************************************************/
/* GetVariableDefinition: Parses and evaluates a single global */
/*   variable in a defglobal construct. Returns TRUE if the    */
/*   variable was successfully parsed and FALSE if a right     */
/*   parenthesis is encountered (signifying the end of the     */
/*   defglobal construct) or an error occurs. The error status */
/*   flag is also set if an error occurs.                      */
/***************************************************************/
static BOOLEAN GetVariableDefinition(readSource,defglobalError,tokenRead,theToken)
  char *readSource;
  int *defglobalError;
  int tokenRead;
  struct token *theToken;
  {
   SYMBOL_HN *variableName;
   struct expr *assignPtr;
   DATA_OBJECT assignValue;

   /*========================================*/
   /* Get next token, which should either be */
   /* a closing parenthesis or a variable.   */
   /*========================================*/

   if (! tokenRead) GetToken(readSource,theToken);
   if (theToken->type == RPAREN) return(CLIPS_FALSE);

   if (theToken->type == SF_VARIABLE)
     {
      SyntaxErrorMessage("defglobal");
      *defglobalError = CLIPS_TRUE;
      return(CLIPS_FALSE);
     }
   else if (theToken->type != GBL_VARIABLE)
     {
      SyntaxErrorMessage("defglobal");
      *defglobalError = CLIPS_TRUE;
      return(CLIPS_FALSE);
     }

   variableName = (SYMBOL_HN *) theToken->value;

   SavePPBuffer(" ");

   /*================================*/
   /* Print out compilation message. */
   /*================================*/

#if DEBUGGING_FUNCTIONS
   if ((GetWatchItem("compilations") == ON) && GetPrintWhileLoading())
     {
      if (QFindDefglobal(variableName) != NULL) PrintCLIPS(WDIALOG,"Redefining defglobal: ?");
      else PrintCLIPS(WDIALOG,"Defining defglobal: ");
      PrintCLIPS(WDIALOG,ValueToString(variableName));
      PrintCLIPS(WDIALOG,"\n");
     }
   else 
#endif
     { if (GetPrintWhileLoading()) PrintCLIPS(WDIALOG,":"); }
     
   /*==================================================================*/