// Reader - CSV record reader for S3Select.
type Reader struct {
	args         *ReaderArgs
	readCloser   io.ReadCloser    // raw input
	buf          *bufio.Reader    // input to the splitter
	columnNames  []string         // names of columns
	nameIndexMap map[string]int64 // name to column index
	current      [][]string       // current block of results to be returned
	recordsRead  int              // number of records read in current slice

// OpenReader returns the reader with an ErrInsecurePath error.
// A future version of Go may introduce this behavior by default.
// Programs that want to accept non-local names can ignore
// the ErrInsecurePath error and use the returned reader.
func OpenReader(name string) (*ReadCloser, error) {
	f, err := os.Open(name)
	if err != nil {
		return nil, err
	}
	fi, err := f.Stat()

// Next returns the header with an [ErrInsecurePath] error.
// A future version of Go may introduce this behavior by default.
// Programs that want to accept non-local names can ignore
// the [ErrInsecurePath] error and use the returned header.
func (tr *Reader) Next() (*Header, error) {
	if tr.err != nil {
		return nil, tr.err
	}
	hdr, err := tr.next()
	tr.err = err