1// fstrmepsilon.cc
2
3// Licensed under the Apache License, Version 2.0 (the "License");
4// you may not use this file except in compliance with the License.
5// You may obtain a copy of the License at
6//
7//     http://www.apache.org/licenses/LICENSE-2.0
8//
9// Unless required by applicable law or agreed to in writing, software
10// distributed under the License is distributed on an "AS IS" BASIS,
11// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12// See the License for the specific language governing permissions and
13// limitations under the License.
14//
15// Copyright 2005-2010 Google, Inc.
16// Author: riley@google.com (Michael Riley)
17// Modified: jpr@google.com (Jake Ratkiewicz) to use FstClass
18//
19// \file
20// Removes epsilons from an FST.
21//
22
23#include <fst/script/rmepsilon.h>
24
25DEFINE_bool(connect, true, "Trim output");
26DEFINE_double(delta, fst::kDelta, "Comparison/quantization delta");
27DEFINE_int64(nstate, fst::kNoStateId, "State number threshold");
28DEFINE_bool(reverse, false, "Perform in the reverse direction");
29DEFINE_string(weight, "", "Weight threshold");
30DEFINE_string(queue_type, "auto", "Queue type: one of: \"auto\", "
31              "\"fifo\", \"lifo\", \"shortest\", \"state\", \"top\"");
32
33int main(int argc, char **argv) {
34  namespace s = fst::script;
35  using fst::script::FstClass;
36  using fst::script::MutableFstClass;
37  using fst::script::VectorFstClass;
38  using fst::script::WeightClass;
39
40  string usage = "Removes epsilons from an FST.\n\n  Usage: ";
41  usage += argv[0];
42  usage += " [in.fst [out.fst]]\n";
43
44  std::set_new_handler(FailedNewHandler);
45  SET_FLAGS(usage.c_str(), &argc, &argv, true);
46  if (argc > 3) {
47    ShowUsage();
48    return 1;
49  }
50
51  string in_fname = (argc > 1 && strcmp(argv[1], "-") != 0) ? argv[1] : "";
52  string out_fname = argc > 2 ? argv[2] : "";
53
54  FstClass *ifst = FstClass::Read(in_fname);
55  if (!ifst) return 1;
56
57  WeightClass weight_threshold = FLAGS_weight.empty() ?
58      WeightClass::Zero() :
59      WeightClass(ifst->WeightType(), FLAGS_weight);
60
61  fst::QueueType qt;
62
63  if (FLAGS_queue_type == "auto") {
64    qt = fst::AUTO_QUEUE;
65  } else if (FLAGS_queue_type == "fifo") {
66    qt = fst::FIFO_QUEUE;
67  } else if (FLAGS_queue_type == "lifo") {
68    qt = fst::LIFO_QUEUE;
69  } else if (FLAGS_queue_type == "shortest") {
70    qt = fst::SHORTEST_FIRST_QUEUE;
71  } else if (FLAGS_queue_type == "state") {
72    qt = fst::STATE_ORDER_QUEUE;
73  } else if (FLAGS_queue_type == "top") {
74    qt = fst::TOP_ORDER_QUEUE;
75  } else {
76    LOG(ERROR) << "Unknown or unsupported queue type: " << FLAGS_queue_type;
77    return 1;
78  }
79
80  s::RmEpsilonOptions opts(qt, FLAGS_delta, FLAGS_connect,
81                           weight_threshold, FLAGS_nstate);
82
83  MutableFstClass *ofst = new VectorFstClass(ifst->ArcType());
84  s::RmEpsilon(*ifst, ofst, FLAGS_reverse, opts);
85
86  ofst->Write(out_fname);
87
88  return 0;
89}
90