利用图遍历路径中位置未知的边和顶点进行ArangoDB主动队列滤波

-- 创建顶点集合
db._createVertexCollection("vertices");

-- 创建边集合
db._createEdgeCollection("edges");

-- 添加一些顶点和边
db.vertices.save({ _key: "A", type: "start" });
db.vertices.save({ _key: "B", type: "middle" });
db.vertices.save({ _key: "C", type: "end" });

db.edges.save("edges/A", "vertices/B", { label: "to_middle" });
db.edges.save("vertices/B", "vertices/C", { label: "to_end" });

const arangojs = require('arangojs');
const { Database } = arangojs;

const db = new Database({ url: 'http://localhost:8529' });
db.useDatabase('your_database_name');
db.useBasicAuth('username', 'password');

async function traverseGraph() {
  const result = await db.traversal({
    startVertex: 'vertices/A',
    direction: 'outbound',
    edgeCollectionRestriction: ['edges'],
    vertexCollectionRestriction: ['vertices'],
    filter: (config, vertex, path) => {
      // 滤波条件：只关心标签为 "to_middle" 的边和类型为 "middle" 的顶点
      if (path.edges.length > 0 && path.edges[path.edges.length - 1].label === 'to_middle' && vertex.type === 'middle') {
        return true;
      }
      return false;
    },
    visitor: (vertex, path) => {
      console.log('Visited vertex:', vertex._key);
    }
  });

  console.log('Traversal result:', result);
}

traverseGraph().catch(console.error);