1 files changed, 148 insertions, 0 deletions
diff --git a/decoder/grammar.cc b/decoder/grammar.cc
new file mode 100644
index 00000000..5eb7887d
--- /dev/null
+++ b/decoder/grammar.cc
@@ -0,0 +1,148 @@
+#include "grammar.h"
+
+#include <algorithm>
+#include <utility>
+#include <map>
+
+#include "rule_lexer.h"
+#include "filelib.h"
+#include "tdict.h"
+
+using namespace std;
+
+const vector<TRulePtr> Grammar::NO_RULES;
+
+RuleBin::~RuleBin() {}
+GrammarIter::~GrammarIter() {}
+Grammar::~Grammar() {}
+
+bool Grammar::HasRuleForSpan(int i, int j, int distance) const {
+  (void) i;
+  (void) j;
+  (void) distance;
+  return true;  // always true by default
+}
+
+struct TextRuleBin : public RuleBin {
+  int GetNumRules() const {
+    return rules_.size();
+  }
+  TRulePtr GetIthRule(int i) const {
+    return rules_[i];
+  }
+  void AddRule(TRulePtr t) {
+    rules_.push_back(t);
+  }
+  int Arity() const {
+    return rules_.front()->Arity();
+  }
+  void Dump() const {
+    for (int i = 0; i < rules_.size(); ++i)
+      cerr << rules_[i]->AsString() << endl;
+  }
+ private:
+  vector<TRulePtr> rules_;
+};
+
+struct TextGrammarNode : public GrammarIter {
+  TextGrammarNode() : rb_(NULL) {}
+  ~TextGrammarNode() {
+    delete rb_;
+  }
+  const GrammarIter* Extend(int symbol) const {
+    map<WordID, TextGrammarNode>::const_iterator i = tree_.find(symbol);
+    if (i == tree_.end()) return NULL;
+    return &i->second;
+  }
+
+  const RuleBin* GetRules() const {
+    if (rb_) {
+      //rb_->Dump();
+    }
+    return rb_;
+  }
+
+  map<WordID, TextGrammarNode> tree_;
+  TextRuleBin* rb_;
+};
+
+struct TGImpl {
+  TextGrammarNode root_;
+};
+
+TextGrammar::TextGrammar() : max_span_(10), pimpl_(new TGImpl) {}
+TextGrammar::TextGrammar(const string& file) : 
+    max_span_(10),
+    pimpl_(new TGImpl) {
+  ReadFromFile(file);
+}
+
+const GrammarIter* TextGrammar::GetRoot() const {
+  return &pimpl_->root_;
+}
+
+void TextGrammar::AddRule(const TRulePtr& rule) {
+  if (rule->IsUnary()) {
+    rhs2unaries_[rule->f().front()].push_back(rule);
+    unaries_.push_back(rule);
+  } else {
+    TextGrammarNode* cur = &pimpl_->root_;
+    for (int i = 0; i < rule->f_.size(); ++i)
+      cur = &cur->tree_[rule->f_[i]];
+    if (cur->rb_ == NULL)
+      cur->rb_ = new TextRuleBin;
+    cur->rb_->AddRule(rule);
+  }
+}
+
+static void AddRuleHelper(const TRulePtr& new_rule, void* extra) {
+  static_cast<TextGrammar*>(extra)->AddRule(new_rule);
+}
+
+void TextGrammar::ReadFromFile(const string& filename) {
+  ReadFile in(filename);
+  RuleLexer::ReadRules(in.stream(), &AddRuleHelper, this);
+}
+
+bool TextGrammar::HasRuleForSpan(int i, int j, int distance) const {
+  return (max_span_ >= distance);
+}
+
+GlueGrammar::GlueGrammar(const string& file) : TextGrammar(file) {}
+
+GlueGrammar::GlueGrammar(const string& goal_nt, const string& default_nt) {
+  TRulePtr stop_glue(new TRule("[" + goal_nt + "] ||| [" + default_nt + ",1] ||| [" + default_nt + ",1]"));
+  TRulePtr glue(new TRule("[" + goal_nt + "] ||| [" + goal_nt + ",1] ["
+    + default_nt + ",2] ||| [" + goal_nt + ",1] [" + default_nt + ",2] ||| Glue=1"));
+
+  AddRule(stop_glue);
+  AddRule(glue);
+  //cerr << "GLUE: " << stop_glue->AsString() << endl;
+  //cerr << "GLUE: " << glue->AsString() << endl;
+}
+
+bool GlueGrammar::HasRuleForSpan(int i, int j, int distance) const {
+  (void) j;
+  return (i == 0);
+}
+
+PassThroughGrammar::PassThroughGrammar(const Lattice& input, const string& cat) :
+    has_rule_(input.size() + 1) {
+  for (int i = 0; i < input.size(); ++i) {
+    const vector<LatticeArc>& alts = input[i];
+    for (int k = 0; k < alts.size(); ++k) {
+      const int j = alts[k].dist2next + i;
+      has_rule_[i].insert(j);
+      const string& src = TD::Convert(alts[k].label);
+      TRulePtr pt(new TRule("[" + cat + "] ||| " + src + " ||| " + src + " ||| PassThrough=1"));
+      AddRule(pt);
+//      cerr << "PT: " << pt->AsString() << endl;
+    }
+  }
+}
+
+bool PassThroughGrammar::HasRuleForSpan(int i, int j, int distance) const {
+  const set<int>& hr = has_rule_[i];
+  if (i == j) { return !hr.empty(); }
+  return (hr.find(j) != hr.end());
+}