jsonl_iterator.h

#ifndef SOURCEMETA_CORE_JSONL_ITERATOR_H_
#define SOURCEMETA_CORE_JSONL_ITERATOR_H_
 
#ifndef SOURCEMETA_CORE_JSONL_EXPORT
#include <sourcemeta/core/jsonl_export.h>
#endif
 
#include <sourcemeta/core/json_value.h>
 
#include <cstddef>  // std::ptrdiff_t
#include <cstdint>  // std::uint64_t
#include <istream>  // std::basic_istream
#include <iterator> // std::forward_iterator_tag
#include <memory>   // std::unique_ptr
 
namespace sourcemeta::core {

enum class JSONLFraming : std::uint8_t {
  LineFeed,
  RecordSeparator
};

class SOURCEMETA_CORE_JSONL_EXPORT ConstJSONLIterator {
public:
  ConstJSONLIterator(std::basic_istream<JSON::Char, JSON::CharTraits> *stream,
                     JSONLFraming framing = JSONLFraming::LineFeed);
  ~ConstJSONLIterator();
  using iterator_category = std::forward_iterator_tag;
  using difference_type = std::ptrdiff_t;
  using value_type = JSON;
  using pointer = const value_type *;
  using reference = const value_type &;
 
  auto operator*() const -> reference;
  auto operator->() const -> pointer;
  auto operator++() -> ConstJSONLIterator &;
 
  SOURCEMETA_CORE_JSONL_EXPORT friend auto
  operator==(const ConstJSONLIterator &left, const ConstJSONLIterator &right)
      -> bool;
 
private:
  std::uint64_t line_{0};
  std::uint64_t column_{0};
  JSONLFraming framing_{JSONLFraming::LineFeed};
  bool at_sequence_start_{true};
  auto parse_next() -> JSON;
  auto parse_next_line() -> JSON;
  auto parse_next_record() -> JSON;
  std::basic_istream<JSON::Char, JSON::CharTraits> *data_{};
 
// Exporting symbols that depends on the standard C++ library is considered
// safe.
// https://learn.microsoft.com/en-us/cpp/error-messages/compiler-warnings/compiler-warning-level-2-c4275?view=msvc-170&redirectedfrom=MSDN
#if defined(_MSC_VER)
#pragma warning(push)
#pragma warning(disable : 4251)
#endif
  // Use PIMPL idiom to hide internal details, mainly
  // templated members, which are tricky to DLL-export.
  struct Internal;
  std::unique_ptr<Internal> internal_{};
#if defined(_MSC_VER)
#pragma warning(pop)
#endif
};
 
} // namespace sourcemeta::core
 
#endif