span_factory.h

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#ifndef __ZGEN_BESTFIRST_SEARCH_SPAN_FACTORY_H__
#define __ZGEN_BESTFIRST_SEARCH_SPAN_FACTORY_H__

#include <vector>
#include "types/instance.h"
#include "knowledge/postag_constrain.h"
#include "bestfirst/search/span.h"
#include "bestfirst/search/span_types.h"
#include "bestfirst/search/span_allocator.h"

namespace ZGen {

namespace BestFirst {

class SpanFactory {
public:
  SpanFactory(const Knowledge::PostagConstrain* constrain,
      SpanAllocator* allocator);

  void create_initial_spans_from_input(const dependency_t* input_ref,
      std::vector<Span *>& spans);

  void create_spans_from_chart(const Span* span,
      const SpanKMaxHeap* charts,
      std::vector<Span *>& spans);

  void create_gold_spans_from_reference(const dependency_t* input,
      const dependency_t* reference,
      SpanSet& spans);
protected:


  virtual bool legal_to_left_combine(const Span* head,
      const Span* modifier) const;

  virtual bool legal_to_right_combine(const Span* head,
      const Span* modifier) const;
private:
  typedef std::vector<int> edges_t;

private:
  Span* create_gold_spans_from_reference_travel(int now,
      const dependency_t* input,
      const dependency_t* reference,
      const std::vector< edges_t>& left_modifiers_tree,
      const std::vector< edges_t>& right_modifiers_tree,
      SpanSet& spans);

private:
  SpanAllocator* allocator;
  const Knowledge::PostagConstrain* constrain;
};

} //  end for namespace Bestfirst

} //  end for namespace ZGen

#endif  //  end for __ZGEN_BESTFIRST_SEARCH_SPAN_FACTORY_H__