Loop Subgraph

LoopSubgraph is a special node type designed to represent a subgraph of nodes that are executed in a loop structure within a larger computational graph. Instead of being executed directly, a LoopSubgraph acts as a container for a set of inner nodes, which are managed and executed repeatedly by the parent graph according to the loop logic.

The LoopSubgraph is included in the main graph as a single node, but internally contains multiple nodes that will be executed repeatedly. The connection and execution of the loop is controlled by the parent graph rather than the LoopSubgraph itself.

pub struct LoopSubgraph {
    id: NodeId,
    name: NodeName,
    in_channels: InChannels,
    out_channels: OutChannels,
    // Inner nodes, contains the nodes that need to be executed in a loop
    inner_nodes: Vec<Arc<Mutex<dyn Node>>>,
}

LoopSubgraph is implemented by Node trait, so Graph will treat LoopSubgraph as a single node. Users need to add nodes that need to form a loop structure to LoopSubgraph, and then add it to Graph.

Use cases of the LoopSubgraph can be found in example - loop subgraph.