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Diffstat (limited to 'decoder/csplit.cc')
| -rw-r--r-- | decoder/csplit.cc | 173 |
1 files changed, 173 insertions, 0 deletions
diff --git a/decoder/csplit.cc b/decoder/csplit.cc new file mode 100644 index 00000000..b1a30fb0 --- /dev/null +++ b/decoder/csplit.cc @@ -0,0 +1,173 @@ +#include "csplit.h" + +#include <iostream> + +#include "filelib.h" +#include "stringlib.h" +#include "hg.h" +#include "tdict.h" +#include "grammar.h" +#include "sentence_metadata.h" + +using namespace std; + +struct CompoundSplitImpl { + CompoundSplitImpl(const boost::program_options::variables_map& conf) : + fugen_elements_(true), // TODO configure + min_size_(3), + kXCAT(TD::Convert("X")*-1), + kWORDBREAK_RULE(new TRule("[X] ||| # ||| #")), + kTEMPLATE_RULE(new TRule("[X] ||| [X,1] ? ||| [1] ?")), + kGOAL_RULE(new TRule("[Goal] ||| [X,1] ||| [1]")), + kFUGEN_S(FD::Convert("FugS")), + kFUGEN_N(FD::Convert("FugN")) {} + + void PasteTogetherStrings(const vector<string>& chars, + const int i, + const int j, + string* yield) { + int size = 0; + for (int k=i; k<j; ++k) + size += chars[k].size(); + yield->resize(size); + int cur = 0; + for (int k=i; k<j; ++k) { + const string& cs = chars[k]; + for (int l = 0; l < cs.size(); ++l) + (*yield)[cur++] = cs[l]; + } + } + + void BuildTrellis(const vector<string>& chars, + Hypergraph* forest) { + vector<int> nodes(chars.size()+1, -1); + nodes[0] = forest->AddNode(kXCAT)->id_; // source + const int left_rule = forest->AddEdge(kWORDBREAK_RULE, Hypergraph::TailNodeVector())->id_; + forest->ConnectEdgeToHeadNode(left_rule, nodes[0]); + + const int max_split_ = max(static_cast<int>(chars.size()) - min_size_ + 1, 1); + cerr << "max: " << max_split_ << " " << " min: " << min_size_ << endl; + for (int i = min_size_; i < max_split_; ++i) + nodes[i] = forest->AddNode(kXCAT)->id_; + assert(nodes.back() == -1); + nodes.back() = forest->AddNode(kXCAT)->id_; // sink + + for (int i = 0; i < max_split_; ++i) { + if (nodes[i] < 0) continue; + const int start = min(i + min_size_, static_cast<int>(chars.size())); + for (int j = start; j <= chars.size(); ++j) { + if (nodes[j] < 0) continue; + string yield; + PasteTogetherStrings(chars, i, j, &yield); + // cerr << "[" << i << "," << j << "] " << yield << endl; + TRulePtr rule = TRulePtr(new TRule(*kTEMPLATE_RULE)); + rule->e_[1] = rule->f_[1] = TD::Convert(yield); + // cerr << rule->AsString() << endl; + int edge = forest->AddEdge( + rule, + Hypergraph::TailNodeVector(1, nodes[i]))->id_; + forest->ConnectEdgeToHeadNode(edge, nodes[j]); + forest->edges_[edge].i_ = i; + forest->edges_[edge].j_ = j; + + // handle "fugenelemente" here + // don't delete "fugenelemente" at the end of words + if (fugen_elements_ && j != chars.size()) { + const int len = yield.size(); + string alt; + int fid = 0; + if (len > (min_size_ + 2) && yield[len-1] == 's' && yield[len-2] == 'e') { + alt = yield.substr(0, len - 2); + fid = kFUGEN_S; + } else if (len > (min_size_ + 1) && yield[len-1] == 's') { + alt = yield.substr(0, len - 1); + fid = kFUGEN_S; + } else if (len > (min_size_ + 2) && yield[len-2] == 'e' && yield[len-1] == 'n') { + alt = yield.substr(0, len - 1); + fid = kFUGEN_N; + } + if (alt.size()) { + TRulePtr altrule = TRulePtr(new TRule(*rule)); + altrule->e_[1] = TD::Convert(alt); + // cerr << altrule->AsString() << endl; + int edge = forest->AddEdge( + altrule, + Hypergraph::TailNodeVector(1, nodes[i]))->id_; + forest->ConnectEdgeToHeadNode(edge, nodes[j]); + forest->edges_[edge].feature_values_.set_value(fid, 1.0); + forest->edges_[edge].i_ = i; + forest->edges_[edge].j_ = j; + } + } + } + } + + // add goal rule + Hypergraph::TailNodeVector tail(1, forest->nodes_.size() - 1); + Hypergraph::Node* goal = forest->AddNode(TD::Convert("Goal")*-1); + Hypergraph::Edge* hg_edge = forest->AddEdge(kGOAL_RULE, tail); + forest->ConnectEdgeToHeadNode(hg_edge, goal); + } + private: + const bool fugen_elements_; + const int min_size_; + const WordID kXCAT; + const TRulePtr kWORDBREAK_RULE; + const TRulePtr kTEMPLATE_RULE; + const TRulePtr kGOAL_RULE; + const int kFUGEN_S; + const int kFUGEN_N; +}; + +CompoundSplit::CompoundSplit(const boost::program_options::variables_map& conf) : + pimpl_(new CompoundSplitImpl(conf)) {} + +static void SplitUTF8String(const string& in, vector<string>* out) { + out->resize(in.size()); + int i = 0; + int c = 0; + while (i < in.size()) { + const int len = UTF8Len(in[i]); + assert(len); + (*out)[c] = in.substr(i, len); + ++c; + i += len; + } + out->resize(c); +} + +bool CompoundSplit::TranslateImpl(const string& input, + SentenceMetadata* smeta, + const vector<double>& weights, + Hypergraph* forest) { + if (input.find(" ") != string::npos) { + cerr << " BAD INPUT: " << input << "\n CompoundSplit expects single words\n"; + abort(); + } + vector<string> in; + SplitUTF8String(input, &in); + smeta->SetSourceLength(in.size()); // TODO do utf8 or somethign + for (int i = 0; i < in.size(); ++i) + smeta->src_lattice_.push_back(vector<LatticeArc>(1, LatticeArc(TD::Convert(in[i]), 0.0, 1))); + pimpl_->BuildTrellis(in, forest); + forest->Reweight(weights); + return true; +} + +int CompoundSplit::GetFullWordEdgeIndex(const Hypergraph& forest) { + assert(forest.nodes_.size() > 0); + const vector<int> out_edges = forest.nodes_[0].out_edges_; + int max_edge = -1; + int max_j = -1; + for (int i = 0; i < out_edges.size(); ++i) { + const int j = forest.edges_[out_edges[i]].j_; + if (j > max_j) { + max_j = j; + max_edge = out_edges[i]; + } + } + assert(max_edge >= 0); + assert(max_edge < forest.edges_.size()); + return max_edge; +} + |