Mutation concepts

The mutation concepts define the different ways a graph can be modified. The hierarchy of mutation interface duplicates the traversal hierarchy and adds functionality to mutate the graph.

• IMutableGraph defines a graph that can be cleared,
• IMutableIncidenceGraph defines methods to remove out-edges,
• IMutableVertexListGraph defines methods to add and remove vertices,
• IMutableEdgeListGraph defines methods to add and remove edges
• IMutableVertexAndEdgeListGraph merges the two above concepts,
• IMutableBidirectionalGraph defines method to remove out-edges