1
2// Licensed under the Apache License, Version 2.0 (the "License");
3// you may not use this file except in compliance with the License.
4// You may obtain a copy of the License at
5//
6//     http://www.apache.org/licenses/LICENSE-2.0
7//
8// Unless required by applicable law or agreed to in writing, software
9// distributed under the License is distributed on an "AS IS" BASIS,
10// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
11// See the License for the specific language governing permissions and
12// limitations under the License.
13//
14// Copyright 2005-2010 Google, Inc.
15// Author: jpr@google.com (Jake Ratkiewicz)
16
17#ifndef FST_SCRIPT_RANDGEN_H_
18#define FST_SCRIPT_RANDGEN_H_
19
20#include <fst/script/arg-packs.h>
21#include <fst/script/fst-class.h>
22#include <fst/randgen.h>
23
24namespace fst {
25namespace script {
26
27enum RandArcSelection {
28  UNIFORM_ARC_SELECTOR,
29  LOG_PROB_ARC_SELECTOR,
30  FAST_LOG_PROB_ARC_SELECTOR
31};
32
33typedef args::Package<const FstClass &, MutableFstClass*, int32,
34                      const RandGenOptions<RandArcSelection> &> RandGenArgs;
35
36template<class Arc>
37void RandGen(RandGenArgs *args) {
38  const Fst<Arc> &ifst = *(args->arg1.GetFst<Arc>());
39  MutableFst<Arc> *ofst = args->arg2->GetMutableFst<Arc>();
40  int32 seed = args->arg3;
41  const RandGenOptions<RandArcSelection> &opts = args->arg4;
42
43  if (opts.arc_selector == UNIFORM_ARC_SELECTOR) {
44    UniformArcSelector<Arc> arc_selector(seed);
45    RandGenOptions< UniformArcSelector<Arc> >
46        ropts(arc_selector, opts.max_length,
47              opts.npath, opts.weighted);
48    RandGen(ifst, ofst, ropts);
49  } else if (opts.arc_selector == FAST_LOG_PROB_ARC_SELECTOR) {
50    FastLogProbArcSelector<Arc> arc_selector(seed);
51    RandGenOptions< FastLogProbArcSelector<Arc> >
52        ropts(arc_selector, opts.max_length,
53              opts.npath, opts.weighted);
54    RandGen(ifst, ofst, ropts);
55  } else {
56    LogProbArcSelector<Arc> arc_selector(seed);
57    RandGenOptions< LogProbArcSelector<Arc> >
58        ropts(arc_selector, opts.max_length,
59              opts.npath, opts.weighted);
60    RandGen(ifst, ofst, ropts);
61  }
62}
63
64
65// Client-facing prototype
66void RandGen(const FstClass &ifst, MutableFstClass *ofst, int32 seed = time(0),
67             const RandGenOptions<RandArcSelection> &opts =
68             fst::RandGenOptions<fst::script::RandArcSelection>(
69                 fst::script::UNIFORM_ARC_SELECTOR));
70
71}  // namespace script
72}  // namespace fst
73
74
75
76#endif  // FST_SCRIPT_RANDGEN_H_
77