Class CSVReader

libs/coding/csv_reader.hpp:14–94

namespace coding
{
class CSVReader
{
public:
  using Row = std::vector<std::string>;
  using Rows = std::vector<Row>;

  explicit CSVReader(std::string const & filename, bool hasHeader = false, char delimiter = ',');
  explicit CSVReader(std::istream & stream, bool hasHeader = false, char delimiter = ',');
  explicit CSVReader(Reader const & reader, bool hasHeader = false, char delimiter = ',');

  bool HasHeader() const;
  char GetDelimiter() const;

  Row const & GetHeader() const;
  std::optional<Row> ReadRow();
  Rows ReadAll();

  template <typename Fn>
  void ForEachRow(Fn && fn)
  {
    while (auto const optRow = ReadRow())
      fn(*optRow);
  }

  // The total number of lines read including the header. Count starts at 0.
  size_t GetCurrentLineNumber() const;

private:
  class ReaderInterface
  {
  public:
    virtual ~ReaderInterface() = default;

    virtual std::optional<std::string> ReadLine() = 0;
  };

  class IstreamWrapper : public ReaderInterface
  {
  public:
    explicit IstreamWrapper(std::istream & stream);

    // ReaderInterface overrides:
    std::optional<std::string> ReadLine() override;

  private:
    std::istream & m_stream;
  };

  class ReaderWrapper : public ReaderInterface
  {
  public:
    explicit ReaderWrapper(Reader const & reader);

    // ReaderInterface overrides:
    std::optional<std::string> ReadLine() override;

  private:
    size_t m_pos = 0;