bruhat.h

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/*
  This is bruhat.h

  Copyright (C) 2004,2005 Fokko du Cloux
  part of the Atlas of Lie Groups and Representations

  For license information see the LICENSE file
*/

#ifndef BRUHAT_H  /* guard against multiple inclusions */
#define BRUHAT_H

#include "poset.h"  // containment

namespace atlas {

/******** type declarations *************************************************/

/******** function declarations *********************************************/

/******** type definitions **************************************************/

namespace bruhat {

class BruhatOrder
{
  std::vector<set::EltList> d_hasse; // probably sparse; avoid |BitMap|s
  poset::Poset d_poset;

 public:

// constructors and destructors
  explicit BruhatOrder(const std::vector<set::EltList>& Hasse_diagram)
    : d_hasse(Hasse_diagram), d_poset(0) {}


// accessors

  size_t size() const { return d_hasse.size(); }


  const set::EltList& hasse(size_t x) const {
    return d_hasse[x];
  }

  unsigned long n_comparable() const {
    return poset::n_comparable_from_Hasse(d_hasse);
  }

  // manipulators
  const poset::Poset& poset() {
    fillPoset(); return d_poset;
  }

  private:
  void fillPoset();

}; // |class BruhatOrder|

} // |namespace bruhat|

} // |namespace atlas|

#endif