altering an edge property

[Zincr0]

Given an already created edge (1 to 2), changing the weight doesn't seems to be currently possible

Tested

anEdge, _ := g.Edge(1, 2)
anEdge.Properties.Weight = 5

anEdge.Properties = graph.EdgeProperties{Weight: 11}`

_ = g.AddEdge(1, 2, graph.EdgeWeight(50))`

none changes the weight.

A function to do this or a workaround in documentation would be great. Very nice library btw.

[dominikbraun]

Thanks for your question! You're right: At the moment, edges are immutable. This is mainly because I haven't figured out an appropriate API design yet, but it's definitely a planned feature and it will be a concern in one of the next few releases.

One backward-compatible workaround would be to remove the edge and re-create it with the new weight. In fact, I did this myself and created a small helper function:

func updateEdgeWeight(g graph.Graph[int, int], source, target, value int) {
    _ = g.RemoveEdge(source, target)
    _ = g.AddEdge(source, target, graph.EdgeWeight(value))
}

Using this function, your example could be solved as follows:

updateEdgeWeight(g, 1, 2, 50)

I hope I'll be able to provide a more convenient solution soon!

[dominikbraun]

Graph.UpdateEdge will be part of the upcoming release next Monday.

[dominikbraun]

graph v0.20 introduces support for updating edge properties.