Method parse

lib/po/argument_parser.cpp:13–114

namespace PO {

cxx20::expected<bool, Error> ArgumentParser::SubCommandDescriptor::parse(
    std::FILE *Out, Span<const char *> ProgramNamePrefix, int Argc,
    const char *Argv[], int ArgP, const bool &VersionOpt) noexcept {
  ProgramNames.reserve(ProgramNamePrefix.size() + 1);
  ProgramNames.assign(ProgramNamePrefix.begin(), ProgramNamePrefix.end());
  if (ArgP < Argc) {
    ProgramNames.push_back(Argv[ArgP]);
  }
  ArgumentDescriptor *CurrentDesc = nullptr;
  bool FirstNonOption = true;
  bool Escaped = false;
  auto PositionalIter = PositionalList.cbegin();
  for (int ArgI = ArgP + 1; ArgI < Argc; ++ArgI) {
    std::string_view Arg = Argv[ArgI];
    if (!Escaped && Arg.size() >= 2 && Arg[0] == '-') {
      if (Arg[1] == '-') {
        if (Arg.size() == 2) {
          Escaped = true;
        } else {
          // long option
          if (CurrentDesc && CurrentDesc->nargs() == 0) {
            CurrentDesc->default_value();
          }
          if (auto Res = consume_long_option_with_argument(Arg); !Res) {
            return cxx20::unexpected(Res.error());
          } else {
            CurrentDesc = *Res;
          }
        }
      } else {
        // short options
        if (CurrentDesc && CurrentDesc->nargs() == 0) {
          CurrentDesc->default_value();
        }
        if (auto Res = consume_short_options(Arg); !Res) {
          return cxx20::unexpected(Res.error());
        } else {
          CurrentDesc = *Res;
        }
      }
    } else if (!Escaped && CurrentDesc) {
      if (auto Res = consume_argument(*CurrentDesc, Arg); !Res) {
        return cxx20::unexpected(Res.error());
      }
      CurrentDesc = nullptr;
    } else {
      // no more options
      if (FirstNonOption) {
        FirstNonOption = false;
        if (!SubCommandMap.empty()) {
          if (auto Iter = SubCommandMap.find(Arg);
              Iter != SubCommandMap.end()) {
            auto &Child = this[Iter->second];
            Child.SC->select();
            return Child.parse(Out, ProgramNames, Argc, Argv, ArgI, VersionOpt);
          }
        }
      }