Hyperlinkv0.8.0-beta.28

← Graph

Graph.hasEdgeconsteffect/Graph.ts:1691
(source: NodeIndex, target: NodeIndex): <
  N,
  E,
  T extends Kind = "directed"
>(
  graph: Graph<N, E, T> | MutableGraph<N, E, T>
) => boolean
<N, E, T extends Kind = "directed">(
  graph: Graph<N, E, T> | MutableGraph<N, E, T>,
  source: NodeIndex,
  target: NodeIndex
): boolean

Checks whether an edge exists between two nodes in the graph.

Example (Checking edge existence)

import { Graph } from "effect"

const graph = Graph.mutate(Graph.directed<string, number>(), (mutable) => {
  const nodeA = Graph.addNode(mutable, "Node A")
  const nodeB = Graph.addNode(mutable, "Node B")
  const nodeC = Graph.addNode(mutable, "Node C")
  Graph.addEdge(mutable, nodeA, nodeB, 42)
})

const nodeA = 0
const nodeB = 1
const nodeC = 2

const hasAB = Graph.hasEdge(graph, nodeA, nodeB)
console.log(hasAB) // true

const hasAC = Graph.hasEdge(graph, nodeA, nodeC)
console.log(hasAC) // false
getters
Source effect/Graph.ts:169133 lines
export const hasEdge: {
  (
    source: NodeIndex,
    target: NodeIndex
  ): <N, E, T extends Kind = "directed">(graph: Graph<N, E, T> | MutableGraph<N, E, T>) => boolean
  <N, E, T extends Kind = "directed">(
    graph: Graph<N, E, T> | MutableGraph<N, E, T>,
    source: NodeIndex,
    target: NodeIndex
  ): boolean
} = dual(3, <N, E, T extends Kind = "directed">(
  graph: Graph<N, E, T> | MutableGraph<N, E, T>,
  source: NodeIndex,
  target: NodeIndex
): boolean => {
  const adjacencyList = graph.adjacency.get(source)
  if (adjacencyList === undefined) {
    return false
  }

  // Check if any edge in the adjacency list connects to the target
  for (const edgeIndex of adjacencyList) {
    const edge = graph.edges.get(edgeIndex)
    if (edge !== undefined) {
      const neighbor = graph.type === "undirected" && edge.target === source ? edge.source : edge.target
      if (neighbor === target) {
        return true
      }
    }
  }

  return false
})