initial checkin

git-svn-id: https://ws10smt.googlecode.com/svn/trunk@2 ec762483-ff6d-05da-a07a-a48fb63a330f

1 files changed, 302 insertions, 0 deletions

diff --git a/decoder/bottom_up_parser.cc b/decoder/bottom_up_parser.cc
new file mode 100644
index 00000000..dd54a606
--- /dev/null
+++ b/decoder/bottom_up_parser.cc
@@ -0,0 +1,302 @@
+#include "bottom_up_parser.h"
+
+#include <iostream>
+#include <map>
+
+#include "hg.h"
+#include "array2d.h"
+#include "tdict.h"
+
+using namespace std;
+
+struct ParserStats {
+  ParserStats() : active_items(), passive_items() {}
+  void Reset() { active_items=0; passive_items=0; }
+  void Report() {
+    cerr << "  ACTIVE ITEMS: " << active_items << "\tPASSIVE ITEMS: " << passive_items << endl;
+  }
+  int active_items;
+  int passive_items;
+  void NotifyActive(int i, int j) { ++active_items; }
+  void NotifyPassive(int i, int j) { ++passive_items; }
+};
+
+ParserStats stats;
+
+class ActiveChart;
+class PassiveChart {
+ public:
+  PassiveChart(const string& goal,
+               const vector<GrammarPtr>& grammars,
+               const Lattice& input,
+               Hypergraph* forest);
+  ~PassiveChart();
+
+  inline const vector<int>& operator()(int i, int j) const { return chart_(i,j); }
+  bool Parse();
+  inline int size() const { return chart_.width(); }
+  inline bool GoalFound() const { return goal_idx_ >= 0; }
+  inline int GetGoalIndex() const { return goal_idx_; }
+
+ private:
+  void ApplyRules(const int i,
+                  const int j,
+                  const RuleBin* rules,
+                  const Hypergraph::TailNodeVector& tail,
+                  const float lattice_cost);
+
+  void ApplyRule(const int i,
+                 const int j,
+                 const TRulePtr& r,
+                 const Hypergraph::TailNodeVector& ant_nodes,
+                 const float lattice_cost);
+
+  void ApplyUnaryRules(const int i, const int j);
+
+  const vector<GrammarPtr>& grammars_;
+  const Lattice& input_;
+  Hypergraph* forest_;
+  Array2D<vector<int> > chart_;   // chart_(i,j) is the list of nodes derived spanning i,j
+  typedef map<int, int> Cat2NodeMap;
+  Array2D<Cat2NodeMap> nodemap_;
+  vector<ActiveChart*> act_chart_;
+  const WordID goal_cat_;    // category that is being searched for at [0,n]
+  TRulePtr goal_rule_;
+  int goal_idx_;             // index of goal node, if found
+  const int lc_fid_;
+
+  static WordID kGOAL;       // [Goal]
+};
+
+WordID PassiveChart::kGOAL = 0;
+
+class ActiveChart {
+ public:
+  ActiveChart(const Hypergraph* hg, const PassiveChart& psv_chart) :
+    hg_(hg),
+    act_chart_(psv_chart.size(), psv_chart.size()), psv_chart_(psv_chart) {}
+
+  struct ActiveItem {
+    ActiveItem(const GrammarIter* g, const Hypergraph::TailNodeVector& a, float lcost) :
+      gptr_(g), ant_nodes_(a), lattice_cost(lcost) {}
+    explicit ActiveItem(const GrammarIter* g) :
+      gptr_(g), ant_nodes_(), lattice_cost(0.0) {}
+
+    void ExtendTerminal(int symbol, float src_cost, vector<ActiveItem>* out_cell) const {
+      const GrammarIter* ni = gptr_->Extend(symbol);
+      if (ni) {
+        stats.NotifyActive(-1,-1);  // TRACKING STATS
+        out_cell->push_back(ActiveItem(ni, ant_nodes_, lattice_cost + src_cost));
+      }
+    }
+    void ExtendNonTerminal(const Hypergraph* hg, int node_index, vector<ActiveItem>* out_cell) const {
+      int symbol = hg->nodes_[node_index].cat_;
+      const GrammarIter* ni = gptr_->Extend(symbol);
+      if (!ni) return;
+      stats.NotifyActive(-1,-1);  // TRACKING STATS
+      Hypergraph::TailNodeVector na(ant_nodes_.size() + 1);
+      for (int i = 0; i < ant_nodes_.size(); ++i)
+        na[i] = ant_nodes_[i];
+      na[ant_nodes_.size()] = node_index;
+      out_cell->push_back(ActiveItem(ni, na, lattice_cost));
+    }
+
+    const GrammarIter* gptr_;
+    Hypergraph::TailNodeVector ant_nodes_;
+    float lattice_cost;  // TODO? use SparseVector<double>
+  };
+
+  inline const vector<ActiveItem>& operator()(int i, int j) const { return act_chart_(i,j); }
+  void SeedActiveChart(const Grammar& g) {
+    int size = act_chart_.width();
+    for (int i = 0; i < size; ++i)
+      if (g.HasRuleForSpan(i,i,0))
+        act_chart_(i,i).push_back(ActiveItem(g.GetRoot()));
+  }
+
+  void ExtendActiveItems(int i, int k, int j) {
+    //cerr << "  LOOK(" << i << "," << k << ") for completed items in (" << k << "," << j << ")\n";
+    vector<ActiveItem>& cell = act_chart_(i,j);
+    const vector<ActiveItem>& icell = act_chart_(i,k);
+    const vector<int>& idxs = psv_chart_(k, j);
+    //if (!idxs.empty()) { cerr << "FOUND IN (" << k << "," << j << ")\n"; }
+    for (vector<ActiveItem>::const_iterator di = icell.begin(); di != icell.end(); ++di) {
+      for (vector<int>::const_iterator ni = idxs.begin(); ni != idxs.end(); ++ni) {
+         di->ExtendNonTerminal(hg_, *ni, &cell);
+      }
+    }
+  }
+
+  void AdvanceDotsForAllItemsInCell(int i, int j, const vector<vector<LatticeArc> >& input) {
+    //cerr << "ADVANCE(" << i << "," << j << ")\n";
+    for (int k=i+1; k < j; ++k)
+      ExtendActiveItems(i, k, j);
+
+    const vector<LatticeArc>& out_arcs = input[j-1];
+    for (vector<LatticeArc>::const_iterator ai = out_arcs.begin();
+         ai != out_arcs.end(); ++ai) {
+      const WordID& f = ai->label;
+      const double& c = ai->cost;
+      const int& len = ai->dist2next;
+      //VLOG(1) << "F: " << TD::Convert(f) << endl;
+      const vector<ActiveItem>& ec = act_chart_(i, j-1);
+      for (vector<ActiveItem>::const_iterator di = ec.begin(); di != ec.end(); ++di)
+        di->ExtendTerminal(f, c, &act_chart_(i, j + len - 1));
+    }
+  }
+
+ private:
+  const Hypergraph* hg_;
+  Array2D<vector<ActiveItem> > act_chart_;
+  const PassiveChart& psv_chart_; 
+};
+
+PassiveChart::PassiveChart(const string& goal,
+                           const vector<GrammarPtr>& grammars,
+                           const Lattice& input,
+                           Hypergraph* forest) :
+    grammars_(grammars),
+    input_(input),
+    forest_(forest),
+    chart_(input.size()+1, input.size()+1),
+    nodemap_(input.size()+1, input.size()+1),
+    goal_cat_(TD::Convert(goal) * -1),
+    goal_rule_(new TRule("[Goal] ||| [" + goal + ",1] ||| [" + goal + ",1]")),
+    goal_idx_(-1),
+    lc_fid_(FD::Convert("LatticeCost")) {
+  act_chart_.resize(grammars_.size());
+  for (int i = 0; i < grammars_.size(); ++i)
+    act_chart_[i] = new ActiveChart(forest, *this);
+  if (!kGOAL) kGOAL = TD::Convert("Goal") * -1;
+  cerr << "  Goal category: [" << goal << ']' << endl;
+}
+
+void PassiveChart::ApplyRule(const int i,
+                             const int j,
+                             const TRulePtr& r,
+                             const Hypergraph::TailNodeVector& ant_nodes,
+                             const float lattice_cost) {
+  stats.NotifyPassive(i,j);  // TRACKING STATS
+  Hypergraph::Edge* new_edge = forest_->AddEdge(r, ant_nodes);
+  new_edge->prev_i_ = r->prev_i;
+  new_edge->prev_j_ = r->prev_j;
+  new_edge->i_ = i;
+  new_edge->j_ = j;
+  new_edge->feature_values_ = r->GetFeatureValues();
+  if (lattice_cost)
+    new_edge->feature_values_.set_value(lc_fid_, lattice_cost);
+  Cat2NodeMap& c2n = nodemap_(i,j);
+  const bool is_goal = (r->GetLHS() == kGOAL);
+  const Cat2NodeMap::iterator ni = c2n.find(r->GetLHS());
+  Hypergraph::Node* node = NULL;
+  if (ni == c2n.end()) {
+    node = forest_->AddNode(r->GetLHS());
+    c2n[r->GetLHS()] = node->id_;
+    if (is_goal) {
+      assert(goal_idx_ == -1);
+      goal_idx_ = node->id_;
+    } else {
+      chart_(i,j).push_back(node->id_);
+    }
+  } else {
+    node = &forest_->nodes_[ni->second];
+  }
+  forest_->ConnectEdgeToHeadNode(new_edge, node);
+}
+
+void PassiveChart::ApplyRules(const int i,
+                       const int j,
+                       const RuleBin* rules,
+                       const Hypergraph::TailNodeVector& tail,
+                       const float lattice_cost) {
+  const int n = rules->GetNumRules();
+  for (int k = 0; k < n; ++k)
+    ApplyRule(i, j, rules->GetIthRule(k), tail, lattice_cost);
+}
+
+void PassiveChart::ApplyUnaryRules(const int i, const int j) {
+  const vector<int>& nodes = chart_(i,j);  // reference is important!
+  for (int gi = 0; gi < grammars_.size(); ++gi) {
+    if (!grammars_[gi]->HasRuleForSpan(i,j,input_.Distance(i,j))) continue;
+    for (int di = 0; di < nodes.size(); ++di) {
+      const WordID& cat = forest_->nodes_[nodes[di]].cat_;
+      const vector<TRulePtr>& unaries = grammars_[gi]->GetUnaryRulesForRHS(cat);
+      for (int ri = 0; ri < unaries.size(); ++ri) {
+        // cerr << "At (" << i << "," << j << "): applying " << unaries[ri]->AsString() << endl;
+        const Hypergraph::TailNodeVector ant(1, nodes[di]);
+        ApplyRule(i, j, unaries[ri], ant, 0);  // may update nodes
+      }
+    }
+  }
+}
+
+bool PassiveChart::Parse() {
+  forest_->nodes_.reserve(input_.size() * input_.size() * 2);
+  forest_->edges_.reserve(input_.size() * input_.size() * 1000);  // TODO: reservation??
+  goal_idx_ = -1;
+  for (int gi = 0; gi < grammars_.size(); ++gi)
+    act_chart_[gi]->SeedActiveChart(*grammars_[gi]);
+
+  cerr << "    ";
+  for (int l=1; l<input_.size()+1; ++l) {
+    cerr << '.';
+    for (int i=0; i<input_.size() + 1 - l; ++i) {
+      int j = i + l;
+      for (int gi = 0; gi < grammars_.size(); ++gi) {
+        const Grammar& g = *grammars_[gi];
+        if (g.HasRuleForSpan(i, j, input_.Distance(i, j))) {
+          act_chart_[gi]->AdvanceDotsForAllItemsInCell(i, j, input_);
+
+          const vector<ActiveChart::ActiveItem>& cell = (*act_chart_[gi])(i,j);
+          for (vector<ActiveChart::ActiveItem>::const_iterator ai = cell.begin();
+               ai != cell.end(); ++ai) {
+            const RuleBin* rules = (ai->gptr_->GetRules());
+            if (!rules) continue;
+            ApplyRules(i, j, rules, ai->ant_nodes_, ai->lattice_cost);
+          }
+        }
+      }
+      ApplyUnaryRules(i,j);
+
+      for (int gi = 0; gi < grammars_.size(); ++gi) {
+        const Grammar& g = *grammars_[gi];
+          // deal with non-terminals that were just proved
+          if (g.HasRuleForSpan(i, j, input_.Distance(i,j)))
+            act_chart_[gi]->ExtendActiveItems(i, i, j);
+      }
+    }
+    const vector<int>& dh = chart_(0, input_.size());
+    for (int di = 0; di < dh.size(); ++di) {
+      const Hypergraph::Node& node = forest_->nodes_[dh[di]];
+      if (node.cat_ == goal_cat_) {
+        Hypergraph::TailNodeVector ant(1, node.id_);
+        ApplyRule(0, input_.size(), goal_rule_, ant, 0);
+      }
+    }
+  }
+  cerr << endl;
+
+  if (GoalFound())
+    forest_->PruneUnreachable(forest_->nodes_.size() - 1);
+  return GoalFound();
+}
+
+PassiveChart::~PassiveChart() {
+  for (int i = 0; i < act_chart_.size(); ++i)
+    delete act_chart_[i];
+}
+
+ExhaustiveBottomUpParser::ExhaustiveBottomUpParser(
+    const string& goal_sym,
+    const vector<GrammarPtr>& grammars) :
+  goal_sym_(goal_sym),
+  grammars_(grammars) {}
+
+bool ExhaustiveBottomUpParser::Parse(const Lattice& input,
+                                     Hypergraph* forest) const {
+  stats.Reset();
+  PassiveChart chart(goal_sym_, grammars_, input, forest);
+  const bool result = chart.Parse();
+  stats.Report();
+  return result;
+}