1 // fstdifference.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 // Subtracts an unweighted DFA from an FSA.
21 //
22
23 #include <fst/script/difference.h>
24 #include <fst/script/connect.h>
25
26 DEFINE_string(compose_filter, "auto",
27 "Composition filter, one of: \"alt_sequence\", \"auto\","
28 " \"match\", \"sequence\"");
29 DEFINE_bool(connect, true, "Trim output");
30
main(int argc,char ** argv)31 int main(int argc, char **argv) {
32 namespace s = fst::script;
33 using fst::script::FstClass;
34 using fst::script::MutableFstClass;
35 using fst::script::VectorFstClass;
36
37 string usage = "Subtracts an unweighted DFA from an FSA.\n\n Usage: ";
38 usage += argv[0];
39 usage += " in1.fst in2.fst [out.fst]\n";
40
41 std::set_new_handler(FailedNewHandler);
42 SetFlags(usage.c_str(), &argc, &argv, true);
43 if (argc < 3 || argc > 4) {
44 ShowUsage();
45 return 1;
46 }
47
48 string in1_name = strcmp(argv[1], "-") == 0 ? "" : argv[1];
49 string in2_name = strcmp(argv[2], "-") == 0 ? "" : argv[2];
50 string out_name = argc > 3 ? argv[3] : "";
51
52 if (in1_name.empty() && in2_name.empty()) {
53 LOG(ERROR) << argv[0] << ": Can't take both inputs from standard input.";
54 return 1;
55 }
56
57 FstClass *ifst1 = FstClass::Read(in1_name);
58 if (!ifst1) return 1;
59 FstClass *ifst2 = FstClass::Read(in2_name);
60 if (!ifst2) return 1;
61
62 VectorFstClass ofst(ifst1->ArcType());
63
64 fst::ComposeFilter cf;
65
66 if (FLAGS_compose_filter == "auto") {
67 cf = fst::AUTO_FILTER;
68 } else if (FLAGS_compose_filter == "sequence") {
69 cf = fst::SEQUENCE_FILTER;
70 } else if (FLAGS_compose_filter == "alt_sequence") {
71 cf = fst::ALT_SEQUENCE_FILTER;
72 } else if (FLAGS_compose_filter == "match") {
73 cf = fst::MATCH_FILTER;
74 } else {
75 LOG(ERROR) << argv[0] << ": Bad filter type \""
76 << FLAGS_compose_filter << "\"";
77 return 1;
78 }
79
80 fst::DifferenceOptions opts(FLAGS_connect, cf);
81
82 s::Difference(*ifst1, *ifst2, &ofst, opts);
83
84 ofst.Write(out_name);
85
86 return 0;
87 }
88