1 files changed, 334 insertions, 0 deletions
diff --git a/src/grammar.hh b/src/grammar.hh
new file mode 100644
index 0000000..c489ec5
--- /dev/null
+++ b/src/grammar.hh
@@ -0,0 +1,334 @@
+#pragma once
+
+#include <iostream>
+#include <fstream>
+#include <map>
+#include <sstream>
+#include <string>
+#include <vector>
+#include <set>
+
+#include <msgpack.hpp>
+
+#include "sparse_vector.hh"
+#include "util.hh"
+
+using namespace std;
+
+namespace G {
+
+enum item_type {
+  UNDEFINED,
+  TERMINAL,
+  NON_TERMINAL
+};
+
+struct Item {
+  virtual size_t index() const { return 0; }
+  virtual symbol_t symbol() const { return ""; }
+  virtual item_type type() const { return UNDEFINED; }
+
+  virtual ostream& repr(ostream& os) const { return os << "Item<>"; }
+  virtual ostream& escaped(ostream& os) const { return os << ""; }
+
+  friend ostream&
+  operator<<(ostream& os, const Item& i)
+  {
+    return i.repr(os);
+  };
+};
+
+struct NT : public Item {
+  symbol_t symbol_;
+    size_t index_;
+
+  NT() {}
+
+  NT(string const& s)
+  {
+    index_ = 0; // default
+    string t(s);
+    t.erase(0, 1); t.pop_back(); // remove '[' and ']'
+    istringstream ss(t);
+    if (ss >> index_) { // [i]
+      symbol_ = "";
+      index_ = stoi(s);
+      return;
+    } else {
+      ss.clear();
+      string buf;
+      size_t j = 0;
+      while (ss.good() && getline(ss, buf, ',')) {
+        if (j == 0) {
+          symbol_ = buf;
+        } else {
+          index_ = stoi(buf);
+        }
+        j++;
+      }
+    }
+  }
+
+  virtual size_t index() const { return index_; }
+  virtual symbol_t symbol() const { return symbol_; }
+  virtual item_type type() const { return NON_TERMINAL; }
+
+  virtual ostream&
+  repr(ostream& os) const
+  {
+    return os << "NT<" << symbol_ << "," << index_ << ">";
+  }
+
+  virtual ostream&
+  escaped(ostream& os) const
+  {
+    os << "[" << symbol_;
+    if (index_ > 0)
+      os << "," << index_;
+    os << "]";
+
+    return os;
+  }
+};
+
+struct T : public Item {
+  symbol_t symbol_;
+
+  T(string const& s)
+  {
+    symbol_ = s;
+  }
+
+  virtual symbol_t symbol() const { return symbol_; }
+  virtual item_type type() const { return TERMINAL; }
+
+  virtual ostream&
+  repr(ostream& os) const
+  {
+    return os << "T<" << symbol_ << ">";
+  }
+
+  virtual ostream&
+  escaped(ostream& os) const
+  {
+    os << util::json_escape(symbol_);
+  }
+};
+
+struct Vocabulary
+{
+  unordered_map<symbol_t, size_t> m_;
+  vector<Item*> items_;
+
+  bool
+  is_non_terminal(string const& s)
+  {
+    return s.front() == '[' && s.back() == ']';
+  }
+
+  Item*
+  get(symbol_t const& s)
+  {
+    if (is_non_terminal(s))
+      return new NT(s);
+    if (m_.find(s) != m_.end())
+      return items_[m_[s]];
+    return add(s);
+  }
+
+  Item*
+  add(symbol_t const& s)
+  {
+    size_t next_index_ = items_.size();
+    T* item = new T(s);
+    items_.push_back(item);
+    m_[s] = next_index_;
+
+    return item;
+  }
+};
+
+struct Rule {
+                               NT* lhs;
+                     vector<Item*> rhs;
+                     vector<Item*> target;
+                            size_t arity;
+Sv::SparseVector<string, score_t>* f;
+               map<size_t, size_t> order;
+                            string as_str_;
+
+  Rule() {}
+
+  Rule(string const& s, Vocabulary& vocab) { from_s(this, s, vocab); }
+
+  static void
+  from_s(Rule* r, string const& s, Vocabulary& vocab)
+  {
+    istringstream ss(s);
+    string buf;
+    size_t j = 0, i = 1;
+    r->arity = 0;
+    vector<NT*> rhs_non_terminals;
+    r->f = new Sv::SparseVector<string, score_t>();
+    while (ss >> buf) {
+      if (buf == "|||") { j++; continue; }
+      if (j == 0) {        // left-hand side
+        r->lhs = new NT(buf);
+      } else if (j == 1) { // right-hand side
+        Item* item = vocab.get(buf);
+        r->rhs.push_back(item);
+        if (item->type() == NON_TERMINAL) {
+          r->arity++;
+          rhs_non_terminals.push_back(reinterpret_cast<NT*>(item));
+        }
+      } else if (j == 2) { // target
+        Item* item = vocab.get(buf);
+        if (item->type() == NON_TERMINAL) {
+          r->order.insert(make_pair(i, item->index()));
+          i++;
+          if (item->symbol() == "") { // only [1], [2] ... on target
+            reinterpret_cast<NT*>(item)->symbol_ = \
+             rhs_non_terminals[item->index()-1]->symbol();
+          }
+        }
+        r->target.push_back(item);
+      } else if (j == 3) { // feature vector
+        Sv::SparseVector<string, score_t>::from_s(r->f, buf);
+        // FIXME: this is slow!!!          ^^^ 
+      } else if (j == 4) { // alignment
+      } else {
+        // error
+      }
+      if (j == 4) break;
+    }
+  }
+
+  ostream&
+  repr(ostream& os) const
+  {
+    os << "Rule<lhs=";
+    lhs->repr(os);
+    os << ", rhs:{";
+    for (auto it = rhs.begin(); it != rhs.end(); it++) {
+      (**it).repr(os);
+      if (next(it) != rhs.end()) os << " ";
+    }
+    os << "}, target:{";
+    for (auto it = target.begin(); it != target.end(); it++) {
+      (**it).repr(os);
+      if (next(it) != target.end()) os << " ";
+    }
+    os << "}, f:";
+    f->repr(os);
+    os << ", arity=" << arity << \
+     ", order:{";
+    for (auto it = order.begin(); it != order.end(); it++) {
+      os << it->first << "->" << it->second;
+      if (next(it) != order.end()) os << ", ";
+    }
+    os << "}>";
+
+    return os;
+  }
+
+  ostream&
+  escaped(ostream& os) const
+  {
+    lhs->escaped(os);
+    os << " ||| ";
+    for (auto it = rhs.begin(); it != rhs.end(); it++) {
+      (**it).escaped(os);
+      if (next(it) != rhs.end()) os << " ";
+    }
+    os << " ||| ";
+    for (auto it = target.begin(); it != target.end(); it++) {
+      (**it).escaped(os);
+      if (next(it) != target.end()) os << " ";
+    }
+    os << " ||| ";
+    f->escaped(os);
+    os << " ||| " << \
+     "TODO";
+
+    return os;
+  };
+
+  friend ostream&
+  operator<<(ostream& os, Rule const& r)
+  {
+    return r.repr(os);
+  };
+
+  // --
+  void
+  prep_for_serialization_()
+  {
+    ostringstream os;
+    escaped(os);
+    as_str_ = os.str();
+  };
+  MSGPACK_DEFINE(as_str_);
+  //             ^^^ FIXME
+};
+
+struct Grammar {
+  vector<Rule*> rules;
+  vector<Rule*> flat;
+  vector<Rule*> start_non_terminal;
+  vector<Rule*> start_terminal;
+  set<symbol_t> nts;
+
+  Grammar() {}
+
+  Grammar(string const& fn, Vocabulary& vocab)
+  {
+    ifstream ifs(fn);
+    string line;
+    while (getline(ifs, line)) {
+      G::Rule* r = new G::Rule(line, vocab);
+      rules.push_back(r);
+      nts.insert(r->lhs->symbol());
+      if (r->arity == 0)
+        flat.push_back(r);
+      else if (r->rhs.front()->type() == NON_TERMINAL)
+        start_non_terminal.push_back(r);
+      else
+        start_terminal.push_back(r);
+    }
+  }
+
+  void
+  add_glue(Vocabulary& vocab)
+  {
+    for (auto nt: nts) {
+      ostringstream oss_1;
+      oss_1 << "[S] ||| [" << nt << ",1] ||| [" << nt << ",1] ||| ";
+      cout << oss_1.str() << endl;
+      Rule* r1 = new Rule(oss_1.str(), vocab);
+      rules.push_back(r1); start_non_terminal.push_back(r1);
+      ostringstream oss_2;
+      oss_2 << "[S] ||| [S,1] [" << nt << ",2] ||| [S,1] [" << nt << ",2] ||| ";
+      cout << oss_2.str() << endl;
+      Rule* r2 = new Rule(oss_2.str(), vocab);
+      cout << *r2 << endl;
+      rules.push_back(r2); start_non_terminal.push_back(r2);
+    }
+  }
+
+  void add_pass_through(const string& input);
+  //   ^^^ TODO
+
+  friend ostream&
+  operator<<(ostream& os, Grammar const& g)
+  {
+    for (const auto it: g.rules) {
+      it->repr(os);
+      os << endl;
+    }
+
+    return os;
+  }
+};
+
+} // namespace G
+