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//========================================================================
//
// Lexer.h
//
// Copyright 1996-2003 Glyph & Cog, LLC
//
//========================================================================
//========================================================================
//
// Modified under the Poppler project - http://poppler.freedesktop.org
//
// All changes made under the Poppler project to this file are licensed
// under GPL version 2 or later
//
// Copyright (C) 2006, 2007, 2010, 2013, 2017-2019 Albert Astals Cid <aacid@kde.org>
// Copyright (C) 2006 Krzysztof Kowalczyk <kkowalczyk@gmail.com>
// Copyright (C) 2013 Adrian Johnson <ajohnson@redneon.com>
// Copyright (C) 2013 Thomas Freitag <Thomas.Freitag@alfa.de>
// Copyright (C) 2019 Adam Reichold <adam.reichold@t-online.de>
//
// To see a description of the changes please see the Changelog file that
// came with your tarball or type make ChangeLog if you are building from git
//
//========================================================================
#ifndef LEXER_H
#define LEXER_H
#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 *xrefA, Stream *str);
// Construct a lexer for a stream or array of streams (assumes obj
// is either a stream or array of streams).
Lexer(XRef *xrefA, Object *obj);
// Destructor.
~Lexer();
Lexer(const Lexer &) = delete;
Lexer &operator=(const Lexer &) = delete;
// Get the next object from the input stream.
Object getObj(int objNum = -1);
Object getObj(const char *cmdA, int objNum);
template<typename T>
Object getObj(T) = delete;
// 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.isStream() ? curStr.getStream() : nullptr; }
// Get current position in file. This is only used for error
// messages.
Goffset getPos() const { return curStr.isStream() ? curStr.getStream()->getPos() : -1; }
// Set position in file.
void setPos(Goffset pos)
{
if (curStr.isStream())
curStr.getStream()->setPos(pos);
}
// Returns true if <c> is a whitespace character.
static bool isSpace(int c);
// often (e.g. ~30% on PDF Refernce 1.6 pdf file from Adobe site) getChar
// is called right after lookChar. In order to avoid expensive re-doing
// getChar() of underlying stream, we cache the last value found by
// lookChar() in lookCharLastValueCached. A special value
// LOOK_VALUE_NOT_CACHED that should never be part of stream indicates
// that no value was cached
static const int LOOK_VALUE_NOT_CACHED = -3;
int lookCharLastValueCached;
XRef *getXRef() const { return xref; }
bool hasXRef() const { return xref != nullptr; }
private:
int getChar(bool comesFromLook = false);
int lookChar();
Array *streams; // array of input streams
int strPtr; // index of current stream
Object curStr; // current stream
bool freeArray; // should lexer free the streams array?
char tokBuf[tokBufSize]; // temporary token buffer
XRef *xref;
};
#endif
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