monora / jgraphl Goto Github PK

Java seems not to have an abstraction of numbers or arithmetic values.

I first thought that the class Numbers would fill this role and designed a WeightedEdge<V, W extends Number> like this

public interface WeightedEdge<V, W extends Number> {
    W weight();
}

but this does not allow to formulate calculations with the weights, i.e. something like

public interface WeightedPath<V, E extends WeightedEdge<V, W>, W extends Number> 
    extends Path<V, E> {

    default W distance() {
        // Problem: Number.plus() does not exist
        return edges().reduce((sum, edge) -> sum.plus(edge.weight())); 
    }
}

So do we have to declare WeightedEdge to always use double for weights??

Public javadoc pages should be available early in development. Requirements:

• the main documentation referenced in README.md
• hosted by github
• easy to build and deploy

Using markdown for index in src/site did note work. Why?

Having the first working version of the graph concepts, we should rethink the interface hierarchy. The concepts of the Boost Graph Library should be our guideline. Should we also introduce these interfaces?

• IncidenceGraph and/or AdjacencyGraph
• BidirectionalGraph
• AdjacencyMatrix
• VertexListGraph, EdgeListGraph

To have the feature to visualize graphs early in development would be nice. Which library should we use? RGL uses graphviz which is not Java based and a bit old. Is there a better choice?

Implement BFS function like BGLs breadth_first_visit

• Search could be implemented as a stream BfsStream starting from a given vertex (see RGL:Graph#bfs_iterator)
• BfsStream should be a GraphVisitor or BGL Visitor