Classes for virtual topologies

public class Cartcomm extends Intracomm {

  public Object clone() { ... }

  // Topology Constructors

  static public int [] Dims_create(int nnodes, int ndims) {...}

  public CartParms Get() {...}

  public int Rank(int [] coords) {...}

  public int [] Coords(int rank) {...}

  public ShiftParms Shift(int direction, int disp) {...}

  public Cartcomm Sub(boolean [] remain_dims) {...}

  public int Map(int [] dims, boolean [] periods) {...}
}

public class CartParms {

  // Return type for Cartcomm.Get()

  public int [] dims ;
  public booleans [] periods ;
  public int [] coords ; 
}

public class ShiftParms {

  // Return type for Cartcomm.Shift()

  public int rank_source ;
  public int rank_dest ; 
}

public class Graphcomm extends Intracomm {

  public Object clone() { ... }

  // Topology Constructors

  public GraphParms Get() {...}

  public int [] Neighbours(int rank) {...}

  public int Map(int [] index, int [] edges) {...}
}

public class GraphParms {

  // Return type for Graphcomm.Get()

  public int [] index ;
  public int [] edges ; 
}