DSL entry point. Initialises an empty graph and evaluates the body, returning the fully built graph.

Example

iex> import Oi.Flowgraph
iex> graph = graph do
...>   step OiTest.DummyOiStep.Greet
...>   step OiTest.DummyOiStep.Exclaim
...>   greet.greeting ~> exclaim.text
...> end
iex> map_size(graph.nodes)
2
iex> MapSet.size(graph.edges)
1

Add multiple steps at once when they share no options.

All modules are validated at compile time just like step/1. Equivalent to calling step for each module with no options.

Example

many_step [LoadPosts, LoadPages, LoadImages]

See Oi.Topology.Graph.new/0.

Add a step to the accumulated graph.

The module must use Oi.Step (i.e. expose __node_spec__/0). Validated at compile time — raises ArgumentError if the module does not implement the expected contract.

Options

• :as — node alias (default: module's declared name)
• :opts — keyword list forwarded as step options

Connect two node ports.

Both sides accept two forms:

• node.port — dot-expression
• {node, port} — explicit tuple