Function map

test-app/runtime/src/main/cpp/ada/ada.cpp:2826–2868

Map the characters according to IDNA, returning the empty string on error.

// Map the characters according to IDNA, returning the empty string on error.
std::u32string map(std::u32string_view input) {
  //  [Map](https://www.unicode.org/reports/tr46/#ProcessingStepMap).
  //  For each code point in the domain_name string, look up the status
  //  value in Section 5, [IDNA Mapping
  //  Table](https://www.unicode.org/reports/tr46/#IDNA_Mapping_Table),
  //  and take the following actions:
  //    * disallowed: Leave the code point unchanged in the string, and
  //    record that there was an error.
  //    * ignored: Remove the code point from the string. This is
  //    equivalent to mapping the code point to an empty string.
  //    * mapped: Replace the code point in the string by the value for
  //    the mapping in Section 5, [IDNA Mapping
  //    Table](https://www.unicode.org/reports/tr46/#IDNA_Mapping_Table).
  //    * valid: Leave the code point unchanged in the string.
  static std::u32string error = U"";
  std::u32string answer;
  answer.reserve(input.size());
  for (char32_t x : input) {
    size_t index = find_range_index(x);
    uint32_t descriptor = table[index][1];
    uint8_t code = uint8_t(descriptor);
    switch (code) {
      case 0:
        break;  // nothing to do, ignored
      case 1:
        answer.push_back(x);  // valid, we just copy it to output
        break;
      case 2:
        return error;  // disallowed
      // case 3 :
      default:
        // We have a mapping
        {
          size_t char_count = (descriptor >> 24);
          uint16_t char_index = uint16_t(descriptor >> 8);
          for (size_t idx = char_index; idx < char_index + char_count; idx++) {
            answer.push_back(mappings[idx]);
          }
        }
    }
  }
  return answer;
}
}  // namespace ada::idna
/* end file src/mapping.cpp */
/* begin file src/normalization.cpp */