pdftops/Lexer.h

   1 //========================================================================
   2 //
   3 // Lexer.h
   4 //
   5 // Copyright 1996-2003 Glyph & Cog, LLC
   6 //
   7 //========================================================================
   8
   9 #ifndef LEXER_H
  10 #define LEXER_H
  11
  12 #include <config.h>
  13
  14 #ifdef USE_GCC_PRAGMAS
  15 #pragma interface
  16 #endif
  17
  18 #include "Object.h"
  19 #include "Stream.h"
  20
  21 class XRef;
  22
  23 #define tokBufSize 128          // size of token buffer
  24
  25 //------------------------------------------------------------------------
  26 // Lexer
  27 //------------------------------------------------------------------------
  28
  29 class Lexer {
  30 public:
  31
  32   // Construct a lexer for a single stream.  Deletes the stream when
  33   // lexer is deleted.
  34   Lexer(XRef *xref, Stream *str);
  35
  36   // Construct a lexer for a stream or array of streams (assumes obj
  37   // is either a stream or array of streams).
  38   Lexer(XRef *xref, Object *obj);
  39
  40   // Destructor.
  41   ~Lexer();
  42
  43   // Get the next object from the input stream.
  44   Object *getObj(Object *obj);
  45
  46   // Skip to the beginning of the next line in the input stream.
  47   void skipToNextLine();
  48
  49   // Skip over one character.
  50   void skipChar() { getChar(); }
  51
  52   // Get stream.
  53   Stream *getStream()
  54     { return curStr.isNone() ? (Stream *)NULL : curStr.getStream(); }
  55
  56   // Get current position in file.  This is only used for error
  57   // messages, so it returns an int instead of a Guint.
  58   int getPos()
  59     { return curStr.isNone() ? -1 : (int)curStr.streamGetPos(); }
  60
  61   // Set position in file.
  62   void setPos(Guint pos, int dir = 0)
  63     { if (!curStr.isNone()) curStr.streamSetPos(pos, dir); }
  64
  65   // Returns true if <c> is a whitespace character.
  66   static GBool isSpace(int c);
  67
  68 private:
  69
  70   int getChar();
  71   int lookChar();
  72
  73   Array *streams;               // array of input streams
  74   int strPtr;                   // index of current stream
  75   Object curStr;                // current stream
  76   GBool freeArray;              // should lexer free the streams array?
  77   char tokBuf[tokBufSize];      // temporary token buffer
  78 };
  79
  80 #endif