Function parse_header

lite/example/cpp_example/npy.h:338–378

}  // namespace pyparse

inline void parse_header(std::string header, std::string& descr) {
    /*
       The first 6 bytes are a magic string: exactly "x93NUMPY".
       The next 1 byte is an unsigned byte: the major version number of the file
       format, e.g. x01. The next 1 byte is an unsigned byte: the minor version
       number of the file format, e.g. x00. Note: the version of the file format
       is not tied to the version of the numpy package. The next 2 bytes form a
       little-endian unsigned short int: the length of the header data
       HEADER_LEN. The next HEADER_LEN bytes form the header data describing the
       array's format. It is an ASCII string which contains a Python literal
       expression of a dictionary. It is terminated by a newline ('n') and
       padded with spaces
       ('x20') to make the total length of the magic string + 4 + HEADER_LEN be
       evenly divisible by 16 for alignment purposes. The dictionary contains
       three keys:

       "descr" : dtype.descr
       An object that can be passed as an argument to the numpy.dtype()
       constructor to create the array's dtype. For repeatability and
       readability, this dictionary is formatted using pprint.pformat() so the
       keys are in alphabetic order.
     */

    // remove trailing newline
    if (header.back() != '\n')
        fprintf(stderr, "invalid header");
    header.pop_back();

    // parse the dictionary
    std::vector<std::string> keys{"descr"};
    auto dict_map = npy::pyparse::parse_dict(header, keys);

    if (dict_map.size() == 0)
        fprintf(stderr, "invalid dictionary in header");

    std::string descr_s = dict_map["descr"];
    parse_typestring(descr_s);
    // remove
    descr = npy::pyparse::parse_str(descr_s);
    return;
}

inline void parse_header(
        std::string header, std::string& descr, bool& fortran_order,