xlnt/source/detail/serialization/serialisation_helpers.hpp

#ifndef XLNT_DETAIL_SERIALISATION_HELPERS_HPP
#define XLNT_DETAIL_SERIALISATION_HELPERS_HPP

#include <xlnt/cell/cell_type.hpp>
#include <xlnt/cell/index_types.hpp>
#include <string>

namespace xlnt {
namespace detail {

/// parsing assumptions used by the following functions
/// - on entry, the start element for the element has been consumed by parser->next
/// - on exit, the closing element has been consumed by parser->next
/// using these assumptions, the following functions DO NOT use parser->peek (SLOW!!!)
/// probable further gains from not building an attribute map and using the attribute events instead as the impl just iterates the map

/// 'r' == cell reference e.g. 'A1'
/// https://docs.microsoft.com/en-us/openspecs/office_standards/ms-oe376/db11a912-b1cb-4dff-b46d-9bedfd10cef0
///
/// a lightweight version of xlnt::cell_reference with no extre functionality (absolute/relative, ...)
/// many thousands are created during (de)serialisation, so even minor overhead is noticable
struct Cell_Reference
{
    // the obvious ctor
    explicit Cell_Reference(xlnt::row_t row_arg, xlnt::column_t::index_t column_arg) noexcept
        : row(row_arg), column(column_arg)
    {
    }

    // the common case. row # is already known during parsing (from parent <row> element)
    // just need to evaluate the column
    explicit Cell_Reference(xlnt::row_t row_arg, const std::string &reference) noexcept
        : row(row_arg)
    {
        // only three characters allowed for the column
        // assumption:
        // - regex pattern match: [A-Z]{1,3}\d{1,7}
        const char *iter = reference.c_str();
        int temp = *iter - 'A' + 1; // 'A' == 1
        ++iter;
        if (*iter >= 'A') // second char
        {
            temp *= 26; // LHS values are more significant
            temp += *iter - 'A' + 1; // 'A' == 1
            ++iter;
            if (*iter >= 'A') // third char
            {
                temp *= 26; // LHS values are more significant
                temp += *iter - 'A' + 1; // 'A' == 1
            }
        }
        column = static_cast<xlnt::column_t::index_t>(temp);
    }

    // for sorting purposes
    bool operator<(const Cell_Reference &rhs)
    {
        // row first, serialisation is done by row then column
        if (row < rhs.row)
        {
            return true;
        }
        else if (rhs.row < row)
        {
            return false;
        }
        // same row, column comparison
        return column < rhs.column;
    }

    xlnt::row_t row; // range:[1, 1048576]
    xlnt::column_t::index_t column; // range:["A", "ZZZ"] -> [1, 26^3] -> [1, 17576]
};

// <c> inside <row> element
// https://docs.microsoft.com/en-us/dotnet/api/documentformat.openxml.spreadsheet.cell?view=openxml-2.8.1
struct Cell
{
    // sort cells by location, row first
    bool operator<(const Cell &rhs)
    {
        return ref < rhs.ref;
    }

    bool is_phonetic = false; // 'ph'
    xlnt::cell_type type = xlnt::cell_type::number; // 't'
    int cell_metatdata_idx = -1; // 'cm'
    int style_index = -1; // 's'
    Cell_Reference ref{0, 0}; // 'r'
    std::string value; // <v> OR <is>
    std::string formula_string; // <f>
};

} // namespace detail
} // namespace xlnt
#endif