Struct WorkflowDag 

pub struct WorkflowDag {
    pub nodes: HashMap<NodeId, WorkflowNode>,
    pub edges: Vec<WorkflowEdge>,
    /* private fields */
}

A directed acyclic graph of WorkflowNodes connected by WorkflowEdges.

Provides cycle detection and Kahn’s-algorithm topological sort.

The topological sort result is cached after the first computation and invalidated automatically whenever the graph topology changes (node or edge mutations).

Fields

nodes: HashMap<NodeId, WorkflowNode>

Nodes, keyed by their ID.

edges: Vec<WorkflowEdge>

Edges in insertion order.

Implementations

impl WorkflowDag

pub fn new() -> Self

Create an empty DAG.

pub fn add_node(&mut self, node: WorkflowNode) -> Result<NodeId, DagError>

Add a node. Returns an error if the node ID already exists.

pub fn add_edge(&mut self, edge: WorkflowEdge) -> Result<(), DagError>

Add an edge. Both nodes must already exist.

pub fn has_cycle(&self) -> bool

Returns true if the DAG contains a cycle (DFS-based).

pub fn topological_sort(&self) -> Result<Vec<NodeId>, DagError>

Topological sort using Kahn’s algorithm.

Returns nodes in an order where every dependency appears before its dependents. The result is cached after the first call and reused on subsequent calls until the graph topology changes.

pub fn predecessors(&self, node_id: NodeId) -> Vec<NodeId>

Return immediate predecessors of node_id.

pub fn successors(&self, node_id: NodeId) -> Vec<NodeId>

Return immediate successors of node_id.

impl WorkflowDag

pub fn execute_with_branches( &mut self, branches: &HashMap<NodeId, BranchNode>, executor: Option<&dyn Fn(&mut WorkflowNode) -> Result<(), String>>, ) -> Result<DagRunStatus, DagError>

Execute the DAG with branch support.

For each branch node found (identified by node IDs in branches), only the selected successor path is activated; the other paths’ nodes are marked Skipped.

Errors

Returns DagError if the DAG contains a cycle.

pub fn descendants(&self, node_id: NodeId) -> HashSet<NodeId>

Return all transitive descendants of the given node.

Trait Implementations

impl Clone for WorkflowDag

fn clone(&self) -> Self

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for WorkflowDag

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Default for WorkflowDag

fn default() -> Self

Returns the “default value” for a type.

impl<'de> Deserialize<'de> for WorkflowDag

fn deserialize<__D>(__deserializer: __D) -> Result<Self, __D::Error>

where __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl Serialize for WorkflowDag

fn serialize<__S>(&self, __serializer: __S) -> Result<__S::Ok, __S::Error>

where __S: Serializer,

Serialize this value into the given Serde serializer.