scanner.h

用于词法分析的词法分析器

/*
  $Id: Scanner.h,v 1.4 1997/02/02 01:30:59 matt Exp $

  Scanner base class.

  (c) Apr 96 Matt Phillips.
  */

#ifndef _SCANNER_H
#define _SCANNER_H

#include "BufferedInputStream.h"
#include "ErrorMessage.h"

class Scanner
{
public:

  enum {SymEOF = -1};

  Scanner (BufferedInputStream &i, ErrorMessageList &e)
    : input (i), errors (e) {symLine = symCol = 0;}

  int eof () const {return symbol == SymEOF;}

  void getNext () {}
  string getFilename () const {return input.getFilename ();}
  int getSymbol () const {return symbol;}
  int getSymbolLine () const {return symLine;}
  int getSymbolColumn () const {return symCol;}
  int getLine () const {return input.getLine ();}
  int getColumn () const {return input.getColumn ();}
  const string &getText () const {return input.getBuffer ();}
  char getText (int pos) const {return input.getBuffer (pos);}
  int getTextLen () const {return input.getBufferSize ();}

  BufferedInputStream &getInput () {return input;}

protected:

  int symbol;
  int symLine, symCol;
  BufferedInputStream &input;
  ErrorMessageList &errors;

  void error (const char *msg)
  {
    errors.error (string (msg), input.getFilename (),
		  symLine, symCol);
  }

  void warning (const char *msg)
  {
    errors.warning (string (msg), input.getFilename (),
		    symLine, symCol);
  }   
};

#endif