core/fpdfapi/parser/cpdf_simple_parser.h

// Copyright 2016 The PDFium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

// Original code copyright 2014 Foxit Software Inc. http://www.foxitsoftware.com

#ifndef CORE_FPDFAPI_PARSER_CPDF_SIMPLE_PARSER_H_
#define CORE_FPDFAPI_PARSER_CPDF_SIMPLE_PARSER_H_

#include <stdint.h>

#include <optional>

#include "core/fxcrt/bytestring.h"
#include "core/fxcrt/span.h"

class CPDF_SimpleParser {
 public:
  explicit CPDF_SimpleParser(pdfium::span<const uint8_t> input);
  ~CPDF_SimpleParser();

  ByteStringView GetWord();

  void SetCurrentPosition(uint32_t position) { cur_position_ = position; }
  uint32_t GetCurrentPosition() const { return cur_position_; }

 private:
  // Returns the ByteStringView of the subspan of `data_` from `start_position`
  // to `cur_position_`.
  ByteStringView GetDataToCurrentPosition(uint32_t start_position) const;

  // Skips whitespace and comment lines. Returns the first parseable character
  // if `data_` can still be parsed, nullopt otherwise.
  std::optional<uint8_t> SkipSpacesAndComments();

  ByteStringView HandleName();
  ByteStringView HandleBeginAngleBracket();
  ByteStringView HandleEndAngleBracket();
  ByteStringView HandleParentheses();
  ByteStringView HandleNonDelimiter();

  const pdfium::span<const uint8_t> data_;

  // The current unread position.
  uint32_t cur_position_ = 0;
};

#endif  // CORE_FPDFAPI_PARSER_CPDF_SIMPLE_PARSER_H_