// See www.openfst.org for extensive documentation on this weighted
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// finite-state transducer library.
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#ifndef FST_EXTENSIONS_SPECIAL_RHO_FST_H_
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#define FST_EXTENSIONS_SPECIAL_RHO_FST_H_
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#include <memory>
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#include <string>
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#include <fst/const-fst.h>
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#include <fst/matcher-fst.h>
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#include <fst/matcher.h>
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DECLARE_int64(rho_fst_rho_label);
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DECLARE_string(rho_fst_rewrite_mode);
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namespace fst {
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namespace internal {
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template <class Label>
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class RhoFstMatcherData {
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public:
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explicit RhoFstMatcherData(
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Label rho_label = FLAGS_rho_fst_rho_label,
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MatcherRewriteMode rewrite_mode = RewriteMode(FLAGS_rho_fst_rewrite_mode))
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: rho_label_(rho_label), rewrite_mode_(rewrite_mode) {}
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RhoFstMatcherData(const RhoFstMatcherData &data)
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: rho_label_(data.rho_label_), rewrite_mode_(data.rewrite_mode_) {}
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static RhoFstMatcherData<Label> *Read(std::istream &istrm,
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const FstReadOptions &read) {
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auto *data = new RhoFstMatcherData<Label>();
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ReadType(istrm, &data->rho_label_);
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int32 rewrite_mode;
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ReadType(istrm, &rewrite_mode);
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data->rewrite_mode_ = static_cast<MatcherRewriteMode>(rewrite_mode);
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return data;
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}
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bool Write(std::ostream &ostrm, const FstWriteOptions &opts) const {
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WriteType(ostrm, rho_label_);
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WriteType(ostrm, static_cast<int32>(rewrite_mode_));
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return !ostrm ? false : true;
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}
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Label RhoLabel() const { return rho_label_; }
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MatcherRewriteMode RewriteMode() const { return rewrite_mode_; }
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private:
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static MatcherRewriteMode RewriteMode(const string &mode) {
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if (mode == "auto") return MATCHER_REWRITE_AUTO;
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if (mode == "always") return MATCHER_REWRITE_ALWAYS;
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if (mode == "never") return MATCHER_REWRITE_NEVER;
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LOG(WARNING) << "RhoFst: Unknown rewrite mode: " << mode << ". "
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<< "Defaulting to auto.";
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return MATCHER_REWRITE_AUTO;
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}
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Label rho_label_;
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MatcherRewriteMode rewrite_mode_;
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};
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} // namespace internal
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constexpr uint8 kRhoFstMatchInput = 0x01; // Input matcher is RhoMatcher.
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constexpr uint8 kRhoFstMatchOutput = 0x02; // Output matcher is RhoMatcher.
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template <class M, uint8 flags = kRhoFstMatchInput | kRhoFstMatchOutput>
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class RhoFstMatcher : public RhoMatcher<M> {
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public:
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using FST = typename M::FST;
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using Arc = typename M::Arc;
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using StateId = typename Arc::StateId;
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using Label = typename Arc::Label;
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using Weight = typename Arc::Weight;
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using MatcherData = internal::RhoFstMatcherData<Label>;
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enum : uint8 { kFlags = flags };
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// This makes a copy of the FST.
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RhoFstMatcher(
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const FST &fst, MatchType match_type,
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std::shared_ptr<MatcherData> data = std::make_shared<MatcherData>())
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: RhoMatcher<M>(fst, match_type,
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RhoLabel(match_type, data ? data->RhoLabel()
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: MatcherData().RhoLabel()),
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data ? data->RewriteMode() : MatcherData().RewriteMode()),
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data_(data) {}
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// This doesn't copy the FST.
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RhoFstMatcher(
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const FST *fst, MatchType match_type,
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std::shared_ptr<MatcherData> data = std::make_shared<MatcherData>())
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: RhoMatcher<M>(fst, match_type,
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RhoLabel(match_type, data ? data->RhoLabel()
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: MatcherData().RhoLabel()),
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data ? data->RewriteMode() : MatcherData().RewriteMode()),
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data_(data) {}
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// This makes a copy of the FST.
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RhoFstMatcher(const RhoFstMatcher<M, flags> &matcher, bool safe = false)
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: RhoMatcher<M>(matcher, safe), data_(matcher.data_) {}
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RhoFstMatcher<M, flags> *Copy(bool safe = false) const override {
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return new RhoFstMatcher<M, flags>(*this, safe);
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}
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const MatcherData *GetData() const { return data_.get(); }
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std::shared_ptr<MatcherData> GetSharedData() const { return data_; }
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private:
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static Label RhoLabel(MatchType match_type, Label label) {
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if (match_type == MATCH_INPUT && flags & kRhoFstMatchInput) return label;
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if (match_type == MATCH_OUTPUT && flags & kRhoFstMatchOutput) return label;
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return kNoLabel;
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}
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std::shared_ptr<MatcherData> data_;
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};
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extern const char rho_fst_type[];
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extern const char input_rho_fst_type[];
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extern const char output_rho_fst_type[];
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using StdRhoFst =
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MatcherFst<ConstFst<StdArc>, RhoFstMatcher<SortedMatcher<ConstFst<StdArc>>>,
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rho_fst_type>;
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using LogRhoFst =
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MatcherFst<ConstFst<LogArc>, RhoFstMatcher<SortedMatcher<ConstFst<LogArc>>>,
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rho_fst_type>;
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using Log64RhoFst = MatcherFst<ConstFst<Log64Arc>,
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RhoFstMatcher<SortedMatcher<ConstFst<Log64Arc>>>,
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input_rho_fst_type>;
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using StdInputRhoFst =
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MatcherFst<ConstFst<StdArc>, RhoFstMatcher<SortedMatcher<ConstFst<StdArc>>,
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kRhoFstMatchInput>,
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input_rho_fst_type>;
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using LogInputRhoFst =
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MatcherFst<ConstFst<LogArc>, RhoFstMatcher<SortedMatcher<ConstFst<LogArc>>,
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kRhoFstMatchInput>,
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input_rho_fst_type>;
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using Log64InputRhoFst = MatcherFst<
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ConstFst<Log64Arc>,
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RhoFstMatcher<SortedMatcher<ConstFst<Log64Arc>>, kRhoFstMatchInput>,
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input_rho_fst_type>;
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using StdOutputRhoFst =
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MatcherFst<ConstFst<StdArc>, RhoFstMatcher<SortedMatcher<ConstFst<StdArc>>,
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kRhoFstMatchOutput>,
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output_rho_fst_type>;
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using LogOutputRhoFst =
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MatcherFst<ConstFst<LogArc>, RhoFstMatcher<SortedMatcher<ConstFst<LogArc>>,
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kRhoFstMatchOutput>,
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output_rho_fst_type>;
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using Log64OutputRhoFst = MatcherFst<
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ConstFst<Log64Arc>,
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RhoFstMatcher<SortedMatcher<ConstFst<Log64Arc>>, kRhoFstMatchOutput>,
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output_rho_fst_type>;
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} // namespace fst
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#endif // FST_EXTENSIONS_SPECIAL_RHO_FST_H_
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