1 files changed, 141 insertions, 0 deletions
diff --git a/src/phrasetable_fst.cc b/src/phrasetable_fst.cc
new file mode 100644
index 00000000..f421e941
--- /dev/null
+++ b/src/phrasetable_fst.cc
@@ -0,0 +1,141 @@
+#include "phrasetable_fst.h"
+
+#include <cassert>
+#include <iostream>
+#include <map>
+
+#include <boost/shared_ptr.hpp>
+
+#include "filelib.h"
+#include "tdict.h"
+
+using boost::shared_ptr;
+using namespace std;
+
+TargetPhraseSet::~TargetPhraseSet() {}
+FSTNode::~FSTNode() {}
+
+class TextTargetPhraseSet : public TargetPhraseSet {
+ public:
+  void AddRule(TRulePtr rule) {
+    rules_.push_back(rule);
+  }
+  const vector<TRulePtr>& GetRules() const {
+    return rules_;
+  }
+
+ private:
+  // all rules must have arity 0
+  vector<TRulePtr> rules_;
+};
+
+class TextFSTNode : public FSTNode {
+ public:
+  const TargetPhraseSet* GetTranslations() const { return data.get(); }
+  bool HasData() const { return (bool)data; }
+  bool HasOutgoingNonEpsilonEdges() const { return !ptr.empty(); } 
+  const FSTNode* Extend(const WordID& t) const {
+    map<WordID, TextFSTNode>::const_iterator it = ptr.find(t);
+    if (it == ptr.end()) return NULL;
+    return &it->second;
+  }
+
+  void AddPhrase(const string& phrase);
+
+  void AddPassThroughTranslation(const WordID& w, const SparseVector<double>& feats);
+  void ClearPassThroughTranslations();
+ private:
+  vector<WordID> passthroughs;
+  shared_ptr<TargetPhraseSet> data;
+  map<WordID, TextFSTNode> ptr;
+};
+
+#ifdef DEBUG_CHART_PARSER
+static string TrimRule(const string& r) {
+  size_t start = r.find(" |||") + 5;
+  size_t end = r.rfind(" |||");
+  return r.substr(start, end - start);
+}
+#endif
+
+void TextFSTNode::AddPhrase(const string& phrase) {
+  vector<WordID> words;
+  TRulePtr rule(TRule::CreateRulePhrasetable(phrase));
+  if (!rule) {
+    static int err = 0;
+    ++err;
+    if (err > 2) { cerr << "TOO MANY PHRASETABLE ERRORS\n"; exit(1); }
+    return;
+  }
+
+  TextFSTNode* fsa = this;
+  for (int i = 0; i < rule->FLength(); ++i)
+    fsa = &fsa->ptr[rule->f_[i]];
+
+  if (!fsa->data)
+    fsa->data.reset(new TextTargetPhraseSet);
+  static_cast<TextTargetPhraseSet*>(fsa->data.get())->AddRule(rule);
+}
+
+void TextFSTNode::AddPassThroughTranslation(const WordID& w, const SparseVector<double>& feats) {
+  TextFSTNode* next = &ptr[w];
+  // current, rules are only added if the symbol is completely missing as a
+  // word starting the phrase.  As a result, it is possible that some sentences
+  // won't parse.  If this becomes a problem, fix it here.
+  if (!next->data) {
+    TextTargetPhraseSet* tps = new TextTargetPhraseSet;
+    next->data.reset(tps);
+    TRule* rule = new TRule;
+    rule->e_.resize(1, w);
+    rule->f_.resize(1, w);
+    rule->lhs_ = TD::Convert("___PHRASE") * -1;
+    rule->scores_ = feats;
+    rule->arity_ = 0;
+    tps->AddRule(TRulePtr(rule));
+    passthroughs.push_back(w); 
+  }
+}
+
+void TextFSTNode::ClearPassThroughTranslations() {
+  for (int i = 0; i < passthroughs.size(); ++i)
+    ptr.erase(passthroughs[i]);
+  passthroughs.clear();
+}
+
+static void AddPhrasetableToFST(istream* in, TextFSTNode* fst) {
+  int lc = 0;
+  bool flag = false;
+  while(*in) {
+    string line;
+    getline(*in, line);
+    if (line.empty()) continue;
+    ++lc;
+    fst->AddPhrase(line);
+    if (lc % 10000 == 0) { flag = true; cerr << '.' << flush; }
+    if (lc % 500000 == 0) { flag = false; cerr << " [" << lc << ']' << endl << flush; }
+  }
+  if (flag) cerr << endl;
+  cerr << "Loaded " << lc << " source phrases\n";
+}
+
+FSTNode* LoadTextPhrasetable(istream* in) {
+  TextFSTNode *fst = new TextFSTNode;
+  AddPhrasetableToFST(in, fst);
+  return fst;
+}
+
+FSTNode* LoadTextPhrasetable(const vector<string>& filenames) {
+  TextFSTNode* fst = new TextFSTNode;
+  for (int i = 0; i < filenames.size(); ++i) {
+    ReadFile rf(filenames[i]);
+    cerr << "Reading phrase from " << filenames[i] << endl;
+    AddPhrasetableToFST(rf.stream(), fst);
+  }
+  return fst;
+}
+
+FSTNode* LoadBinaryPhrasetable(const string& fname_prefix) {
+  (void) fname_prefix;
+  assert(!"not implemented yet");
+}
+