TickTickClock

defmodule MyApp.PageRank do
  use TickTickClock.BSP

  # Declarative superstep definition
  superstep :calculate_rank do
    # Compute phase - runs in parallel
    compute fn vertex ->
      new_rank = 0.15 + 0.85 * sum(vertex.inbox)
      {:ok, %{vertex | rank: new_rank}}
    end

    # Communication phase - automatic synchronization
    communicate do
      send_to :neighbors, fn vertex ->
        contribution = vertex.rank / length(vertex.edges)
        Enum.map(vertex.edges, &{&1, contribution})
      end
    end

    # Convergence check
    converged? fn old, new ->
      abs(new.rank - old.rank) < 0.0001
    end
  end
end