pdftops/Lexer.h

   1 //========================================================================
   2 //
   3 // Lexer.h
   4 //
   5 // Copyright 1996 Derek B. Noonburg
   6 //
   7 //========================================================================
   8
   9 #ifndef LEXER_H
  10 #define LEXER_H
  11
  12 #ifdef __GNUC__
  13 #pragma interface
  14 #endif
  15
  16 #include "Object.h"
  17 #include "Stream.h"
  18
  19 class XRef;
  20
  21 #define tokBufSize 128          // size of token buffer
  22
  23 //------------------------------------------------------------------------
  24 // Lexer
  25 //------------------------------------------------------------------------
  26
  27 class Lexer {
  28 public:
  29
  30   // Construct a lexer for a single stream.  Deletes the stream when
  31   // lexer is deleted.
  32   Lexer(XRef *xref, Stream *str);
  33
  34   // Construct a lexer for a stream or array of streams (assumes obj
  35   // is either a stream or array of streams).
  36   Lexer(XRef *xref, Object *obj);
  37
  38   // Destructor.
  39   ~Lexer();
  40
  41   // Get the next object from the input stream.
  42   Object *getObj(Object *obj);
  43
  44   // Skip to the beginning of the next line in the input stream.
  45   void skipToNextLine();
  46
  47   // Skip over one character.
  48   void skipChar() { getChar(); }
  49
  50   // Get stream.
  51   Stream *getStream()
  52     { return curStr.isNone() ? (Stream *)NULL : curStr.getStream(); }
  53
  54   // Get current position in file.
  55   int getPos()
  56     { return curStr.isNone() ? -1 : curStr.streamGetPos(); }
  57
  58   // Set position in file.
  59   void setPos(int pos)
  60     { if (!curStr.isNone()) curStr.streamSetPos(pos); }
  61
  62 private:
  63
  64   int getChar();
  65   int lookChar();
  66
  67   Array *streams;               // array of input streams
  68   int strPtr;                   // index of current stream
  69   Object curStr;                // current stream
  70   GBool freeArray;              // should lexer free the streams array?
  71   char tokBuf[tokBufSize];      // temporary token buffer
  72 };
  73
  74 #endif