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_PRUNE_H_
18 #define FST_SCRIPT_PRUNE_H_
19
20 #include <vector>
21 using std::vector;
22
23 #include <fst/script/arg-packs.h>
24 #include <fst/script/fst-class.h>
25 #include <fst/script/weight-class.h>
26 #include <fst/prune.h>
27 #include <fst/arcfilter.h>
28
29 namespace fst {
30 namespace script {
31
32 struct PruneOptions {
33 WeightClass weight_threshold;
34 int64 state_threshold;
35 const vector<WeightClass> *distance;
36 float delta;
37
38 explicit PruneOptions(const WeightClass& w, int64 s,
39 vector<WeightClass> *d = 0, float e = kDelta)
weight_thresholdPruneOptions40 : weight_threshold(w),
41 state_threshold(s),
42 distance(d),
43 delta(e) {}
44 private:
45 PruneOptions(); // disallow
46 };
47
48 // converts a script::PruneOptions into a fst::PruneOptions.
49 // Notes:
50 // If the original opts.distance is not NULL, a new distance will be
51 // created with new; it's the client's responsibility to delete this.
52
53 template<class A>
ConvertPruneOptions(const PruneOptions & opts)54 fst::PruneOptions<A, AnyArcFilter<A> > ConvertPruneOptions(
55 const PruneOptions &opts) {
56 typedef typename A::Weight Weight;
57 typedef typename A::StateId StateId;
58
59 Weight weight_threshold = *(opts.weight_threshold.GetWeight<Weight>());
60 StateId state_threshold = opts.state_threshold;
61 vector<Weight> *distance = 0;
62
63 if (opts.distance) {
64 distance = new vector<Weight>(opts.distance->size());
65 for (unsigned i = 0; i < opts.distance->size(); ++i) {
66 (*distance)[i] = *((*opts.distance)[i].GetWeight<Weight>());
67 }
68 }
69
70 return fst::PruneOptions<A, AnyArcFilter<A> >(
71 weight_threshold, state_threshold, AnyArcFilter<A>(), distance,
72 opts.delta);
73 }
74
75 // 1
76 typedef args::Package<MutableFstClass *, const PruneOptions &> PruneArgs1;
77
78 template<class Arc>
Prune(PruneArgs1 * args)79 void Prune(PruneArgs1 *args) {
80 MutableFst<Arc> *ofst = args->arg1->GetMutableFst<Arc>();
81
82 typedef typename Arc::Weight Weight;
83 typedef typename Arc::StateId StateId;
84
85 fst::PruneOptions<Arc, AnyArcFilter<Arc> > opts =
86 ConvertPruneOptions<Arc>(args->arg2);
87 Prune(ofst, opts);
88 delete opts.distance;
89 }
90
91 // 2
92 typedef args::Package<const FstClass &, MutableFstClass *,
93 const PruneOptions &> PruneArgs2;
94
95 template<class Arc>
Prune(PruneArgs2 * args)96 void Prune(PruneArgs2 *args) {
97 const Fst<Arc>& ifst = *(args->arg1.GetFst<Arc>());
98 MutableFst<Arc> *ofst = args->arg2->GetMutableFst<Arc>();
99
100 fst::PruneOptions<Arc, AnyArcFilter<Arc> > opts =
101 ConvertPruneOptions<Arc>(args->arg3);
102 Prune(ifst, ofst, opts);
103 delete opts.distance;
104 }
105
106 // 3
107 typedef args::Package<const FstClass &,
108 MutableFstClass *,
109 const WeightClass &, int64, float> PruneArgs3;
110
111 template<class Arc>
Prune(PruneArgs3 * args)112 void Prune(PruneArgs3 *args) {
113 const Fst<Arc>& ifst = *(args->arg1.GetFst<Arc>());
114 MutableFst<Arc> *ofst = args->arg2->GetMutableFst<Arc>();
115 typename Arc::Weight w = *(args->arg3.GetWeight<typename Arc::Weight>());
116
117 Prune(ifst, ofst, w, args->arg4, args->arg5);
118 }
119
120 // 4
121 typedef args::Package<MutableFstClass *, const WeightClass&,
122 int64, float> PruneArgs4;
123 template<class Arc>
Prune(PruneArgs4 * args)124 void Prune(PruneArgs4 *args) {
125 MutableFst<Arc> *fst = args->arg1->GetMutableFst<Arc>();
126 typename Arc::Weight w = *(args->arg2.GetWeight<typename Arc::Weight>());
127 Prune(fst, w, args->arg3, args->arg4);
128 }
129
130
131 // 1
132 void Prune(MutableFstClass *fst, const PruneOptions &opts);
133
134 // 2
135 void Prune(const FstClass &ifst, MutableFstClass *fst,
136 const PruneOptions &opts);
137
138 // 3
139 void Prune(const FstClass &ifst, MutableFstClass *ofst,
140 const WeightClass &weight_threshold,
141 int64 state_threshold = kNoStateId,
142 float delta = kDelta);
143
144 // 4
145 void Prune(MutableFstClass *fst, const WeightClass& weight_threshold,
146 int64 state_threshold, float delta);
147
148 } // namespace script
149 } // namespace fst
150
151
152
153 #endif // FST_SCRIPT_PRUNE_H_
154