Lexer.h

//========================================================================
//
// Lexer.h
//
// Copyright 1996-2002 Glyph & Cog, LLC
//
//========================================================================
 
#ifndef LEXER_H
#define LEXER_H
 
#include <aconf.h>
 
#ifdef USE_GCC_PRAGMAS
#pragma interface
#endif
 
#include "Object.h"
#include "Stream.h"
 
class XRef;
 
#define tokBufSize 128      // size of token buffer
 
//------------------------------------------------------------------------
// Lexer
//------------------------------------------------------------------------
 
class Lexer {
public:
 
  // Construct a lexer for a single stream.  Deletes the stream when
  // lexer is deleted.
  Lexer(XRef *xref, Stream *str);
 
  // Construct a lexer for a stream or array of streams (assumes obj
  // is either a stream or array of streams).
  Lexer(XRef *xref, Object *obj);
 
  // Destructor.
  ~Lexer();
 
  // Get the next object from the input stream.
  Object *getObj(Object *obj);
 
  // Skip to the beginning of the next line in the input stream.
  void skipToNextLine();
 
  // Skip over one character.
  void skipChar() { getChar(); }
 
  // Get stream.
  Stream *getStream()
    { return curStr.isNone() ? (Stream *)NULL : curStr.getStream(); }
 
  // Get current position in file.  This is only used for error
  // messages, so it returns an int instead of a Guint.
  int getPos()
    { return curStr.isNone() ? -1 : (int)curStr.streamGetPos(); }
 
  // Set position in file.
  void setPos(Guint pos, int dir = 0)
    { if (!curStr.isNone()) curStr.streamSetPos(pos, dir); }
 
private:
 
  int getChar();
  int lookChar();
 
  Array *streams;       // array of input streams
  int strPtr;           // index of current stream
  Object curStr;        // current stream
  GBool freeArray;      // should lexer free the streams array?
  char tokBuf[tokBufSize];  // temporary token buffer
};
 
#endif