4.10.1.2 Iteration

The most common operations in PGX algorithms are iterations (such as looping over all vertices, and looping over a vertex's neighbors) and graph traversal (such as breath-first/depth-first). All collections expose a forEach and forSequential method by which you can iterate over the collection in parallel and in sequence, respectively.

For example:

• To iterate over a graph's vertices in parallel:

  G.getVertices().forEach(v -> {
      ...
  });
  

• To iterate over a graph's vertices in sequence:

  G.getVertices().forSequential(v -> {
      ...
  });
  

• To traverse a graph's vertices from r in breadth-first order:

  import oracle.pgx.algorithm.Traversal;
  
  Traversal.inBFS(G, r).forward(n -> {
      ...
  });
  

  Inside the forward (or backward) lambda you can access the current level of the BFS (or DFS) traversal by calling currentLevel().