Exemplo n.º 1
0
// Converts a SyntaxNode tree to a Moses::GHKM::ParseTree.
std::auto_ptr<ParseTree> XmlTreeParser::ConvertTree(
    const SyntaxNode &tree,
    const std::vector<std::string> &words)
{
  std::auto_ptr<ParseTree> root(new ParseTree(tree.GetLabel()));
  const std::vector<SyntaxNode*> &children = tree.GetChildren();
  if (children.empty()) {
    if (tree.GetStart() != tree.GetEnd()) {
      std::ostringstream msg;
      msg << "leaf node covers multiple words (" << tree.GetStart()
          << "-" << tree.GetEnd() << "): this is currently unsupported";
      throw Exception(msg.str());
    }
    std::auto_ptr<ParseTree> leaf(new ParseTree(words[tree.GetStart()]));
    leaf->SetParent(root.get());
    root->AddChild(leaf.release());
  } else {
    for (std::vector<SyntaxNode*>::const_iterator p = children.begin();
         p != children.end(); ++p) {
      assert(*p);
      std::auto_ptr<ParseTree> child = ConvertTree(**p, words);
      child->SetParent(root.get());
      root->AddChild(child.release());
    }
  }
  return root;
}
void SyntaxTree::ConnectNodes()
{
  typedef SyntaxTreeIndex2::const_reverse_iterator InnerIterator;

  SyntaxNode *prev = 0;
  // Iterate over all start indices from lowest to highest.
  for (SyntaxTreeIndexIterator p = m_index.begin(); p != m_index.end(); ++p) {
    const SyntaxTreeIndex2 &inner = p->second;
    // Iterate over all end indices from highest to lowest.
    for (InnerIterator q = inner.rbegin(); q != inner.rend(); ++q) {
      const std::vector<SyntaxNode*> &nodes = q->second;
      // Iterate over all nodes that cover the same span in order of tree
      // depth, top-most first.
      for (std::vector<SyntaxNode*>::const_reverse_iterator r = nodes.rbegin();
           r != nodes.rend(); ++r) {
        SyntaxNode *node = *r;
        if (!prev) {
          // node is the root.
          m_top = node;
          node->SetParent(0);
        } else if (prev->GetStart() == node->GetStart()) {
          // prev is the parent of node.
          assert(prev->GetEnd() >= node->GetEnd());
          node->SetParent(prev);
          prev->AddChild(node);
        } else {
          // prev is a descendant of node's parent.  The lowest common
          // ancestor of prev and node will be node's parent.
          SyntaxNode *ancestor = prev->GetParent();
          while (ancestor->GetEnd() < node->GetEnd()) {
            ancestor = ancestor->GetParent();
          }
          assert(ancestor);
          node->SetParent(ancestor);
          ancestor->AddChild(node);
        }
        prev = node;
      }
    }
  }
}