mosesdecoder/moses/FF/InternalTree.h

#pragma once

#include <iostream>
#include <string>
#include <map>
#include <vector>
#include "FFState.h"
#include "moses/Word.h"
#include "moses/StaticData.h"
#include <boost/shared_ptr.hpp>
#include <boost/make_shared.hpp>
#include "util/generator.hh"
#include "util/exception.hh"
#include "util/string_piece.hh"

namespace Moses
{

class InternalTree;
typedef boost::shared_ptr<InternalTree> TreePointer;

class InternalTree
{
  Word m_value;
  std::vector<TreePointer> m_children;
public:
  InternalTree(const std::string & line, size_t start, size_t len, const bool terminal);
  InternalTree(const std::string & line, const bool nonterminal = true);
  InternalTree(const InternalTree & tree):
    m_value(tree.m_value) {
    const std::vector<TreePointer> & children = tree.m_children;
    for (std::vector<TreePointer>::const_iterator it = children.begin(); it != children.end(); it++) {
      m_children.push_back(boost::make_shared<InternalTree>(**it));
    }
  }
  size_t AddSubTree(const std::string & line, size_t start);

  std::string GetString(bool start = true) const;
  void Combine(const std::vector<TreePointer> &previous);
  void Unbinarize();
  void GetUnbinarizedChildren(std::vector<TreePointer> &children) const;
  const Word & GetLabel() const {
    return m_value;
  }

  size_t GetLength() const {
    return m_children.size();
  }
  std::vector<TreePointer> & GetChildren() {
    return m_children;
  }

  bool IsTerminal() const {
    return !m_value.IsNonTerminal();
  }

  bool IsLeafNT() const {
    return (m_value.IsNonTerminal() && m_children.size() == 0);
  }

  // different methods to search a tree (either just direct children (FlatSearch) or all children (RecursiveSearch)) for constituents.
  // can be used for formulating syntax constraints.

  // if found, 'it' is iterator to first tree node that matches search string
  bool FlatSearch(const Word & label, std::vector<TreePointer>::const_iterator & it) const;
  bool RecursiveSearch(const Word & label, std::vector<TreePointer>::const_iterator & it) const;

  // if found, 'it' is iterator to first tree node that matches search string, and 'parent' to its parent node
  bool RecursiveSearch(const Word & label, std::vector<TreePointer>::const_iterator & it, InternalTree const* &parent) const;

  // Python-like generator that yields next nonterminal leaf on every call
  $generator(leafNT) {
    std::vector<TreePointer>::iterator it;
    InternalTree* tree;
    leafNT(InternalTree* root = 0): tree(root) {}
    $emit(std::vector<TreePointer>::iterator)
    for (it = tree->GetChildren().begin(); it !=tree->GetChildren().end(); ++it) {
      if (!(*it)->IsTerminal() && (*it)->GetLength() == 0) {
        $yield(it);
      } else if ((*it)->GetLength() > 0) {
        if ((*it).get()) { // normal pointer to same object that TreePointer points to
          $restart(tree = (*it).get());
        }
      }
    }
    $stop;
  };


  // Python-like generator that yields the parent of the next nonterminal leaf on every call
  $generator(leafNTParent) {
    std::vector<TreePointer>::iterator it;
    InternalTree* tree;
    leafNTParent(InternalTree* root = 0): tree(root) {}
    $emit(InternalTree*)
    for (it = tree->GetChildren().begin(); it !=tree->GetChildren().end(); ++it) {
      if (!(*it)->IsTerminal() && (*it)->GetLength() == 0) {
        $yield(tree);
      } else if ((*it)->GetLength() > 0) {
        if ((*it).get()) {
          $restart(tree = (*it).get());
        }
      }
    }
    $stop;
  };

  // Python-like generator that yields the next nonterminal leaf on every call, and also stores the path from the root of the tree to the nonterminal
  $generator(leafNTPath) {
    std::vector<TreePointer>::iterator it;
    InternalTree* tree;
    std::vector<InternalTree*> * path;
    leafNTPath(InternalTree* root = NULL, std::vector<InternalTree*> * orig = NULL): tree(root), path(orig) {}
    $emit(std::vector<TreePointer>::iterator)
    path->push_back(tree);
    for (it = tree->GetChildren().begin(); it !=tree->GetChildren().end(); ++it) {
      if (!(*it)->IsTerminal() && (*it)->GetLength() == 0) {
        path->push_back((*it).get());
        $yield(it);
        path->pop_back();
      } else if ((*it)->GetLength() > 0) {
        if ((*it).get()) {
          $restart(tree = (*it).get());
        }
      }
    }
    path->pop_back();
    $stop;
  };

};

class TreeState : public FFState
{
  TreePointer m_tree;
public:
  TreeState(TreePointer tree)
    :m_tree(tree) {
  }

  TreePointer GetTree() const {
    return m_tree;
  }

  virtual size_t hash() const {
    return 0;
  }
  virtual bool operator==(const FFState& other) const {
    return true;
  }

};

}