// See www.openfst.org for extensive documentation on this weighted
  // finite-state transducer library.
  //
  // Encode transducer labels and/or weights.
  
  #include <cstring>
  
  #include <memory>
  #include <string>
  
  #include <fst/flags.h>
  #include <fst/script/decode.h>
  #include <fst/script/encode.h>
  #include <fst/script/getters.h>
  
  DECLARE_bool(encode_labels);
  DECLARE_bool(encode_weights);
  DECLARE_bool(encode_reuse);
  DECLARE_bool(decode);
  
  int fstencode_main(int argc, char **argv) {
    namespace s = fst::script;
    using fst::script::FstClass;
    using fst::script::MutableFstClass;
  
    string usage = "Encodes transducer labels and/or weights.
  
    Usage: ";
    usage += argv[0];
    usage += " in.fst codex [out.fst]
  ";
  
    std::set_new_handler(FailedNewHandler);
    SET_FLAGS(usage.c_str(), &argc, &argv, true);
    if (argc < 3 || argc > 4) {
      ShowUsage();
      return 1;
    }
  
    const string in_name = (strcmp(argv[1], "-") != 0) ? argv[1] : "";
    const string codex_name = argv[2];
    const string out_name = argc > 3 ? argv[3] : "";
  
    std::unique_ptr<MutableFstClass> fst(MutableFstClass::Read(in_name, true));
    if (!fst) return 1;
  
    if (FLAGS_decode) {
      s::Decode(fst.get(), codex_name);
      return !fst->Write(out_name);
    } else {
      const auto flags =
          s::GetEncodeFlags(FLAGS_encode_labels, FLAGS_encode_weights);
      s::Encode(fst.get(), flags, FLAGS_encode_reuse, codex_name);
      return !fst->Write(out_name);
    }
  }