read_next()

std::optional< Kakshya::CompositeArray > MayaFlux::IO::DelimitedTextReader::read_next ( size_t  max_elements )

overridevirtual

Consume a bounded number of records.

Parameters

max_elements

Maximum records to return; zero returns an empty array without advancing.

Returns

Owning array, empty at end of file, or nullopt on failure.

Implements MayaFlux::IO::CompositeReader.

Definition at line 344 of file DelimitedTextReader.cpp.

{
    if (!is_open() || !m_layout) {
        m_last_error = "No delimited text file is open";
        return std::nullopt;
    }
 
    Kakshya::CompositeArray result(*m_layout);
    std::vector<ParsedField> fields;
 
    while (result.size() < max_elements && !m_at_end) {
        bool at_end = false;
 
        if (!read_record(fields, at_end))
            return std::nullopt;
 
        if (at_end) {
            m_at_end = true;
            break;
        }
 
        if (!append_record(result, fields))
            return std::nullopt;
 
        ++m_row_position;
    }
 
    m_last_error.clear();
    return result;
}

References append_record(), is_open(), m_at_end, MayaFlux::IO::CompositeReader::m_last_error, m_layout, m_row_position, read_record(), and MayaFlux::Kakshya::CompositeArray::size().

Referenced by read_composite().

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