print-impl.h
4.13 KB
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
// See www.openfst.org for extensive documentation on this weighted
// finite-state transducer library.
//
// Stand-alone class to print out binary FSTs in the AT&T format, a helper
// class for fstprint.cc.
#ifndef FST_SCRIPT_PRINT_IMPL_H_
#define FST_SCRIPT_PRINT_IMPL_H_
#include <ostream>
#include <sstream>
#include <string>
#include <fst/fstlib.h>
#include <fst/util.h>
DECLARE_string(fst_field_separator);
namespace fst {
// Print a binary FST in textual format (helper class for fstprint.cc).
// WARNING: Stand-alone use of this class not recommended, most code should
// read/write using the binary format which is much more efficient.
template <class Arc>
class FstPrinter {
public:
using StateId = typename Arc::StateId;
using Label = typename Arc::Label;
using Weight = typename Arc::Weight;
FstPrinter(const Fst<Arc> &fst, const SymbolTable *isyms,
const SymbolTable *osyms, const SymbolTable *ssyms, bool accep,
bool show_weight_one, const string &field_separator,
const string &missing_symbol = "")
: fst_(fst),
isyms_(isyms),
osyms_(osyms),
ssyms_(ssyms),
accep_(accep && fst.Properties(kAcceptor, true)),
ostrm_(nullptr),
show_weight_one_(show_weight_one),
sep_(field_separator),
missing_symbol_(missing_symbol) {}
// Prints FST to an output stream.
void Print(std::ostream *ostrm, const string &dest) {
ostrm_ = ostrm;
dest_ = dest;
const auto start = fst_.Start();
if (start == kNoStateId) return;
// Initial state first.
PrintState(start);
for (StateIterator<Fst<Arc>> siter(fst_); !siter.Done(); siter.Next()) {
const auto s = siter.Value();
if (s != start) PrintState(s);
}
}
private:
void PrintId(StateId id, const SymbolTable *syms, const char *name) const {
if (syms) {
string symbol = syms->Find(id);
if (symbol.empty()) {
if (missing_symbol_.empty()) {
FSTERROR() << "FstPrinter: Integer " << id
<< " is not mapped to any textual symbol"
<< ", symbol table = " << syms->Name()
<< ", destination = " << dest_;
symbol = "?";
} else {
symbol = missing_symbol_;
}
}
*ostrm_ << symbol;
} else {
*ostrm_ << id;
}
}
void PrintStateId(StateId s) const { PrintId(s, ssyms_, "state ID"); }
void PrintILabel(Label l) const { PrintId(l, isyms_, "arc input label"); }
void PrintOLabel(Label l) const { PrintId(l, osyms_, "arc output label"); }
void PrintState(StateId s) const {
bool output = false;
for (ArcIterator<Fst<Arc>> aiter(fst_, s); !aiter.Done(); aiter.Next()) {
const auto &arc = aiter.Value();
PrintStateId(s);
*ostrm_ << sep_;
PrintStateId(arc.nextstate);
*ostrm_ << sep_;
PrintILabel(arc.ilabel);
if (!accep_) {
*ostrm_ << sep_;
PrintOLabel(arc.olabel);
}
if (show_weight_one_ || arc.weight != Weight::One())
*ostrm_ << sep_ << arc.weight;
*ostrm_ << "\n";
output = true;
}
const auto weight = fst_.Final(s);
if (weight != Weight::Zero() || !output) {
PrintStateId(s);
if (show_weight_one_ || weight != Weight::One()) {
*ostrm_ << sep_ << weight;
}
*ostrm_ << "\n";
}
}
const Fst<Arc> &fst_;
const SymbolTable *isyms_; // ilabel symbol table.
const SymbolTable *osyms_; // olabel symbol table.
const SymbolTable *ssyms_; // slabel symbol table.
bool accep_; // Print as acceptor when possible?
std::ostream *ostrm_; // Text FST destination.
string dest_; // Text FST destination name.
bool show_weight_one_; // Print weights equal to Weight::One()?
string sep_; // Separator character between fields.
string missing_symbol_; // Symbol to print when lookup fails (default
// "" means raise error).
//
FstPrinter(const FstPrinter &) = delete;
FstPrinter &operator=(const FstPrinter &) = delete;
};
} // namespace fst
#endif // FST_SCRIPT_PRINT_IMPL_H_