descents.h

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/*
  This is descents.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 DESCENTS_H  /* guard against multiple inclusions */
#define DESCENTS_H

#include <cstring>

namespace atlas {

/******** constant declarations *********************************************/

namespace descents {}

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

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

namespace descents {


class DescentStatus {

  unsigned char d_data[constants::RANK_MAX];
  static const unsigned ValMask = constants::charBits - 1;

  static const unsigned DescentMask = 0x4ul;

  static const unsigned DirectRecursionMask = 0x5ul;

 public:

  enum Value { ComplexAscent, RealNonparity, ImaginaryTypeI, ImaginaryTypeII,
           ImaginaryCompact, ComplexDescent, RealTypeII, RealTypeI };

  static bool isDescent(Value v) {
    return (v & DescentMask)!=0;
  }

  static bool isDirectRecursion(Value v) {
    return (v & DirectRecursionMask) == DirectRecursionMask;
  }

// constructors and destructors
  DescentStatus() { // sets statuses of all simple roots to 0 (ComplexAscent)
    std::memset(d_data,0,constants::RANK_MAX);
  }

  ~DescentStatus() {}

// copy and assignment (these copy statuses of all simple roots)
  DescentStatus(const DescentStatus& ds) {
    std::memcpy(d_data,ds.d_data,constants::RANK_MAX);
  }

  DescentStatus& operator=(const DescentStatus& ds) {
    std::memcpy(d_data,ds.d_data,constants::RANK_MAX);
    return *this;
  }

// accessors

  Value operator[] (size_t s) const {
    return static_cast<Value> (d_data[s]); // cast converts integer to enum
  }

// manipulators

  void set(size_t s, Value v) {
    d_data[s] = v; // no cast needed here; enum value converts to integral type
  }
};

}

}

#endif