// See www.openfst.org for extensive documentation on this weighted
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// finite-state transducer library.
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//
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// These classes are only recommended for use in high-level scripting
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// applications. Most users should use the lower-level templated versions
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// corresponding to these classes.
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#include <istream>
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#include <fst/log.h>
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#include <fst/equal.h>
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#include <fst/fst-decl.h>
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#include <fst/reverse.h>
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#include <fst/union.h>
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#include <fst/script/fst-class.h>
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#include <fst/script/register.h>
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namespace fst {
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namespace script {
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// Registration.
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REGISTER_FST_CLASSES(StdArc);
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REGISTER_FST_CLASSES(LogArc);
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REGISTER_FST_CLASSES(Log64Arc);
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// Helper functions.
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namespace {
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template <class F>
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F *ReadFstClass(std::istream &istrm, const string &fname) {
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if (!istrm) {
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LOG(ERROR) << "ReadFstClass: Can't open file: " << fname;
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return nullptr;
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}
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FstHeader hdr;
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if (!hdr.Read(istrm, fname)) return nullptr;
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const FstReadOptions read_options(fname, &hdr);
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const auto &arc_type = hdr.ArcType();
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static const auto *io_register = IORegistration<F>::Register::GetRegister();
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const auto reader = io_register->GetReader(arc_type);
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if (!reader) {
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LOG(ERROR) << "ReadFstClass: Unknown arc type: " << arc_type;
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return nullptr;
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}
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return reader(istrm, read_options);
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}
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template <class F>
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FstClassImplBase *CreateFstClass(const string &arc_type) {
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static const auto *io_register =
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IORegistration<F>::Register::GetRegister();
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auto creator = io_register->GetCreator(arc_type);
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if (!creator) {
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FSTERROR() << "CreateFstClass: Unknown arc type: " << arc_type;
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return nullptr;
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}
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return creator();
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}
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template <class F>
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FstClassImplBase *ConvertFstClass(const FstClass &other) {
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static const auto *io_register =
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IORegistration<F>::Register::GetRegister();
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auto converter = io_register->GetConverter(other.ArcType());
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if (!converter) {
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FSTERROR() << "ConvertFstClass: Unknown arc type: " << other.ArcType();
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return nullptr;
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}
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return converter(other);
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}
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} // namespace
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// FstClass methods.
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FstClass *FstClass::Read(const string &fname) {
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if (!fname.empty()) {
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std::ifstream istrm(fname, std::ios_base::in | std::ios_base::binary);
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return ReadFstClass<FstClass>(istrm, fname);
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} else {
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return ReadFstClass<FstClass>(std::cin, "standard input");
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}
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}
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FstClass *FstClass::Read(std::istream &istrm, const string &source) {
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return ReadFstClass<FstClass>(istrm, source);
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}
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bool FstClass::WeightTypesMatch(const WeightClass &weight,
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const string &op_name) const {
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if (WeightType() != weight.Type()) {
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FSTERROR() << "FST and weight with non-matching weight types passed to "
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<< op_name << ": " << WeightType() << " and " << weight.Type();
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return false;
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}
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return true;
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}
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// MutableFstClass methods.
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MutableFstClass *MutableFstClass::Read(const string &fname, bool convert) {
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if (convert == false) {
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if (!fname.empty()) {
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std::ifstream in(fname, std::ios_base::in | std::ios_base::binary);
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return ReadFstClass<MutableFstClass>(in, fname);
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} else {
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return ReadFstClass<MutableFstClass>(std::cin, "standard input");
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}
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} else { // Converts to VectorFstClass if not mutable.
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std::unique_ptr<FstClass> ifst(FstClass::Read(fname));
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if (!ifst) return nullptr;
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if (ifst->Properties(kMutable, false) == kMutable) {
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return static_cast<MutableFstClass *>(ifst.release());
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} else {
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return new VectorFstClass(*ifst.release());
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}
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}
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}
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// VectorFstClass methods.
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VectorFstClass *VectorFstClass::Read(const string &fname) {
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if (!fname.empty()) {
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std::ifstream in(fname, std::ios_base::in | std::ios_base::binary);
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return ReadFstClass<VectorFstClass>(in, fname);
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} else {
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return ReadFstClass<VectorFstClass>(std::cin, "standard input");
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}
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}
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VectorFstClass::VectorFstClass(const string &arc_type)
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: MutableFstClass(CreateFstClass<VectorFstClass>(arc_type)) {}
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VectorFstClass::VectorFstClass(const FstClass &other)
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: MutableFstClass(ConvertFstClass<VectorFstClass>(other)) {}
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} // namespace script
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} // namespace fst
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