1 // fstshortestdistance.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: allauzen@google.com (Cyril Allauzen)
17 // Modified: jpr@google.com (Jake Ratkiewicz) to use FstClass
18 //
19 // \file
20 // Find shortest distances in an FST.
21
22 #include <string>
23 #include <vector>
24 using std::vector;
25
26 #include <fst/script/shortest-distance.h>
27 #include <fst/script/text-io.h>
28
29 DEFINE_bool(reverse, false, "Perform in the reverse direction");
30 DEFINE_double(delta, fst::kDelta, "Comparison/quantization delta");
31 DEFINE_int64(nstate, fst::kNoStateId, "State number threhold");
32 DEFINE_string(queue_type, "auto", "Queue type: one of: \"auto\", "
33 "\"fifo\", \"lifo\", \"shortest\", \"state\", \"top\"");
34
main(int argc,char ** argv)35 int main(int argc, char **argv) {
36 namespace s = fst::script;
37 using fst::script::FstClass;
38
39 string usage = "Finds shortest distance(s) in an FST.\n\n Usage: ";
40 usage += argv[0];
41 usage += " [in.fst [distance.txt]]\n";
42
43 std::set_new_handler(FailedNewHandler);
44 SET_FLAGS(usage.c_str(), &argc, &argv, true);
45 if (argc > 3) {
46 ShowUsage();
47 return 1;
48 }
49
50 string in_fname = (argc > 1 && (strcmp(argv[1], "-") != 0)) ? argv[1] : "";
51 string out_fname = argc > 2 ? argv[2] : "";
52
53 FstClass *ifst = FstClass::Read(in_fname);
54 if (!ifst) return 1;
55
56 vector<s::WeightClass> distance;
57
58 fst::QueueType qt;
59
60 if (FLAGS_queue_type == "auto") {
61 qt = fst::AUTO_QUEUE;
62 } else if (FLAGS_queue_type == "fifo") {
63 qt = fst::FIFO_QUEUE;
64 } else if (FLAGS_queue_type == "lifo") {
65 qt = fst::LIFO_QUEUE;
66 } else if (FLAGS_queue_type == "shortest") {
67 qt = fst::SHORTEST_FIRST_QUEUE;
68 } else if (FLAGS_queue_type == "state") {
69 qt = fst::STATE_ORDER_QUEUE;
70 } else if (FLAGS_queue_type == "top") {
71 qt = fst::TOP_ORDER_QUEUE;
72 } else {
73 LOG(ERROR) << "Unknown or unsupported queue type: " << FLAGS_queue_type;
74 return 1;
75 }
76
77 if (FLAGS_reverse && qt != fst::AUTO_QUEUE) {
78 LOG(ERROR) << "Specifying a non-default queue with reverse not supported.";
79 return 1;
80 }
81
82 if (FLAGS_reverse) {
83 s::ShortestDistance(*ifst, &distance, FLAGS_reverse, FLAGS_delta);
84 } else {
85 s::ShortestDistanceOptions opts(qt, s::ANY_ARC_FILTER,
86 FLAGS_nstate, FLAGS_delta);
87 s::ShortestDistance(*ifst, &distance, opts);
88 }
89
90 s::WritePotentials(out_fname, distance);
91
92 return 0;
93 }
94