// Copyright 2003, Trustees of Indiana University
// Please see the license in the file ../LICENSE

using System;
using GCollections;

public interface GraphEdge<Vertex> {
  Vertex source {get;}
  Vertex target {get;}
}

public interface VertexListGraph<Vertex,VertexIterator>
  where VertexIterator: IEnumerable<Vertex> {
  VertexIterator vertices();
  int num_vertices();
}

public interface IncidenceGraph<
		  Vertex,
		  Edge,
		  OutEdgeIterator>
    where OutEdgeIterator: IEnumerable<Edge> {
  OutEdgeIterator out_edges(Vertex v);
  int out_degree(Vertex v);
}

public interface EdgeListGraph<
		  Vertex,
		  Edge,
		  EdgeIterator>
  where Edge: GraphEdge<Vertex>,
	EdgeIterator: IEnumerable<Edge>
{
  EdgeIterator edges();
}

public interface VertexListAndIncidenceGraph<
  Vertex,
  Edge,
  VertexIterator,
  OutEdgeIterator>
    : VertexListGraph<Vertex,VertexIterator>,
      IncidenceGraph<Vertex,Edge,OutEdgeIterator>
  where Edge: GraphEdge<Vertex>,
	VertexIterator: IEnumerable<Vertex>,
	OutEdgeIterator: IEnumerable<Edge>
  {}

public interface VertexListAndIncidenceAndEdgeListGraph<
  Vertex,
  Edge,
  VertexIterator,
  OutEdgeIterator,
  EdgeIterator>:
    VertexListAndIncidenceGraph<Vertex,Edge,VertexIterator,OutEdgeIterator>,
    EdgeListGraph<Vertex,Edge,EdgeIterator>
  where Edge: GraphEdge<Vertex>,
	VertexIterator: IEnumerable<Vertex>,
	OutEdgeIterator: IEnumerable<Edge>,
	EdgeIterator: IEnumerable<Edge>
  {}