Method traverse

packages/graph/src/Steps.ts:3547–3587

(
    source: GraphSource<any>,
    input: Iterable<TraversalPath<any, any, any>>,
    _context?: QueryContext,
  )

  }

  public *traverse(
    source: GraphSource<any>,
    input: Iterable<TraversalPath<any, any, any>>,
    _context?: QueryContext,
  ): IterableIterator<TraversalPath<any, any, any>> {
    const { direction, edgeLabels, stepLabels } = this.config;
    for (const path of input) {
      this.traversed++;
      const value = path.value;
      if (value === undefined) continue;
      if (value instanceof Vertex) {
        if (direction === "in" || direction === "both") {
          for (const edge of source.getIncomingEdges(value.id)) {
            this.traversed++;
            if (edgeLabels.length === 0 || edgeLabels.includes(edge.label)) {
              this.emitted++;
              yield path.with(edge, stepLabels);
            }
          }
        }
        if (direction === "out" || direction === "both") {
          for (const edge of source.getOutgoingEdges(value.id)) {
            this.traversed++;
            if (edgeLabels.length === 0 || edgeLabels.includes(edge.label)) {
              // For direction='both', skip self-loops since they were already
              // yielded in the incoming edges pass above
              const storedEdge = edge[$StoredElement];
              if (direction === "both" && storedEdge.inV === storedEdge.outV) {
                continue;
              }
              this.emitted++;
              yield path.with(edge, stepLabels);
            }
          }
        }
      } else if (value instanceof Edge) {
        this.emitted++;
        yield path;
      }
    }
  }

  public override clone(partial?: Partial<EdgeStepConfig>) {
    const { config } = this;