Function getDirectedNeighbors

packages/effect/src/Graph.ts:2623–2647

(
  graph: Graph<N, E, "directed"> | MutableGraph<N, E, "directed">,
  nodeIndex: NodeIndex,
  direction: Direction
)

): number => graphImpl(graph).edges.size

const getDirectedNeighbors = <N, E>(
  graph: Graph<N, E, "directed"> | MutableGraph<N, E, "directed">,
  nodeIndex: NodeIndex,
  direction: Direction
): Array<NodeIndex> => {
  const impl = graphImpl(graph)
  const adjacencyMap = direction === "incoming"
    ? impl.reverseAdjacency
    : impl.adjacency

  const adjacencyList = adjacencyMap.get(nodeIndex)
  if (adjacencyList === undefined) {
    return []
  }

  const result: Array<NodeIndex> = []
  for (const edgeIndex of adjacencyList) {
    const edge = impl.edges.get(edgeIndex)
    if (edge !== undefined) {
      result.push(direction === "incoming" ? edge.source : edge.target)
    }
  }

  return result
}

/**
 * Returns the neighboring node indices for a node.