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Diffstat (limited to 'src/include/fst/script/rmepsilon.h')
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diff --git a/src/include/fst/script/rmepsilon.h b/src/include/fst/script/rmepsilon.h new file mode 100644 index 0000000..62fed03 --- /dev/null +++ b/src/include/fst/script/rmepsilon.h @@ -0,0 +1,211 @@ + +// Licensed under the Apache License, Version 2.0 (the "License"); +// you may not use this file except in compliance with the License. +// You may obtain a copy of the License at +// +// http://www.apache.org/licenses/LICENSE-2.0 +// +// Unless required by applicable law or agreed to in writing, software +// distributed under the License is distributed on an "AS IS" BASIS, +// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +// See the License for the specific language governing permissions and +// limitations under the License. +// +// Copyright 2005-2010 Google, Inc. +// Author: jpr@google.com (Jake Ratkiewicz) + +#ifndef FST_SCRIPT_RMEPSILON_H_ +#define FST_SCRIPT_RMEPSILON_H_ + +#include <vector> +using std::vector; + +#include <fst/script/arg-packs.h> +#include <fst/script/fst-class.h> +#include <fst/script/weight-class.h> +#include <fst/script/shortest-distance.h> // for ShortestDistanceOptions +#include <fst/rmepsilon.h> +#include <fst/queue.h> + +// the following is necessary, or SWIG complains mightily about +// shortestdistanceoptions not being defined before being used as a base. +#ifdef SWIG +%include "nlp/fst/script/shortest-distance.h" +#endif + + +namespace fst { +namespace script { + +// +// OPTIONS +// + +struct RmEpsilonOptions : public fst::script::ShortestDistanceOptions { + bool connect; + WeightClass weight_threshold; + int64 state_threshold; + + RmEpsilonOptions(QueueType qt = AUTO_QUEUE, float d = kDelta, bool c = true, + WeightClass w = fst::script::WeightClass::Zero(), + int64 n = kNoStateId) + : ShortestDistanceOptions(qt, EPSILON_ARC_FILTER, + kNoStateId, d), + connect(c), weight_threshold(w), state_threshold(n) { } +}; + + +// +// TEMPLATES +// + +// this function takes care of transforming a script-land RmEpsilonOptions +// into a lib-land RmEpsilonOptions +template<class Arc> +void RmEpsilonHelper(MutableFst<Arc> *fst, + vector<typename Arc::Weight> *distance, + const RmEpsilonOptions &opts) { + typedef typename Arc::StateId StateId; + typedef typename Arc::Weight Weight; + + typename Arc::Weight weight_thresh = + *(opts.weight_threshold.GetWeight<Weight>()); + + switch (opts.queue_type) { + case AUTO_QUEUE: { + AutoQueue<StateId> queue(*fst, distance, EpsilonArcFilter<Arc>()); + fst::RmEpsilonOptions<Arc, AutoQueue<StateId> > ropts( + &queue, opts.delta, opts.connect, weight_thresh, + opts.state_threshold); + RmEpsilon(fst, distance, ropts); + break; + } + case FIFO_QUEUE: { + FifoQueue<StateId> queue; + fst::RmEpsilonOptions<Arc, FifoQueue<StateId> > ropts( + &queue, opts.delta, opts.connect, weight_thresh, + opts.state_threshold); + RmEpsilon(fst, distance, ropts); + break; + } + case LIFO_QUEUE: { + LifoQueue<StateId> queue; + fst::RmEpsilonOptions<Arc, LifoQueue<StateId> > ropts( + &queue, opts.delta, opts.connect, weight_thresh, + opts.state_threshold); + RmEpsilon(fst, distance, ropts); + break; + } + case SHORTEST_FIRST_QUEUE: { + NaturalShortestFirstQueue<StateId, Weight> queue(*distance); + fst::RmEpsilonOptions<Arc, NaturalShortestFirstQueue<StateId, + Weight> > ropts( + &queue, opts.delta, opts.connect, weight_thresh, + opts.state_threshold); + RmEpsilon(fst, distance, ropts); + break; + } + case STATE_ORDER_QUEUE: { + StateOrderQueue<StateId> queue; + fst::RmEpsilonOptions<Arc, StateOrderQueue<StateId> > ropts( + &queue, opts.delta, opts.connect, weight_thresh, + opts.state_threshold); + RmEpsilon(fst, distance, ropts); + break; + } + case TOP_ORDER_QUEUE: { + TopOrderQueue<StateId> queue(*fst, EpsilonArcFilter<Arc>()); + fst::RmEpsilonOptions<Arc, TopOrderQueue<StateId> > ropts( + &queue, opts.delta, opts.connect, weight_thresh, + opts.state_threshold); + RmEpsilon(fst, distance, ropts); + break; + } + default: + FSTERROR() << "Unknown or unsupported queue type: " << opts.queue_type; + fst->SetProperties(kError, kError); + } +} + +// 1 +typedef args::Package<const FstClass &, MutableFstClass *, + bool, const RmEpsilonOptions &> RmEpsilonArgs1; + +template<class Arc> +void RmEpsilon(RmEpsilonArgs1 *args) { + const Fst<Arc> &ifst = *(args->arg1.GetFst<Arc>()); + MutableFst<Arc> *ofst = args->arg2->GetMutableFst<Arc>(); + vector<typename Arc::Weight> distance; + bool reverse = args->arg3; + + if (reverse) { + VectorFst<Arc> rfst; + Reverse(ifst, &rfst); + RmEpsilonHelper(&rfst, &distance, args->arg4); + Reverse(rfst, ofst); + } else { + *ofst = ifst; + } + RmEpsilonHelper(ofst, &distance, args->arg4); +} + +// 2 +typedef args::Package<MutableFstClass *, bool, + const WeightClass, int64, + float> RmEpsilonArgs2; + +template<class Arc> +void RmEpsilon(RmEpsilonArgs2 *args) { + MutableFst<Arc> *fst = args->arg1->GetMutableFst<Arc>(); + typename Arc::Weight w = *(args->arg3.GetWeight<typename Arc::Weight>()); + + RmEpsilon(fst, args->arg2, w, args->arg4, args->arg5); +} + +// 3 +typedef args::Package<MutableFstClass *, vector<WeightClass> *, + const RmEpsilonOptions &> RmEpsilonArgs3; + +template<class Arc> +void RmEpsilon(RmEpsilonArgs3 *args) { + MutableFst<Arc> *fst = args->arg1->GetMutableFst<Arc>(); + const RmEpsilonOptions &opts = args->arg3; + + vector<typename Arc::Weight> weights; + + RmEpsilonHelper(fst, &weights, opts); + + // Copy the weights back + args->arg2->resize(weights.size()); + for (unsigned i = 0; i < weights.size(); ++i) { + (*args->arg2)[i] = WeightClass(weights[i]); + } +} + +// +// PROTOTYPES +// + +// 1 +void RmEpsilon(const FstClass &ifst, MutableFstClass *ofst, + bool reverse = false, + const RmEpsilonOptions& opts = + fst::script::RmEpsilonOptions()); + +// 2 +void RmEpsilon(MutableFstClass *arc, bool connect = true, + const WeightClass &weight_threshold = + fst::script::WeightClass::Zero(), + int64 state_threshold = fst::kNoStateId, + float delta = fst::kDelta); + +// 3 +void RmEpsilon(MutableFstClass *fst, vector<WeightClass> *distance, + const RmEpsilonOptions &opts); + + +} // namespace script +} // namespace fst + + +#endif // FST_SCRIPT_RMEPSILON_H_ |