Struct WorkflowDag 

pub struct WorkflowDag {
    pub name: String,
    pub nodes: BTreeMap<String, DagNode>,
    pub levels: Vec<Vec<String>>,
    pub roots: Vec<String>,
    pub leaves: Vec<String>,
}

The workflow DAG — compiled from WorkflowConfig.

Contains the full dependency graph and supports:

• Topological ordering
• Parallel level grouping
• Dependency queries
• Root/leaf detection

Fields

name: String

The workflow name.

nodes: BTreeMap<String, DagNode>

All nodes in the DAG, keyed by step ID.

BTreeMap (not HashMap) is intentional: it makes iteration order deterministic across runs, so roots/leaves/levels are stable — important for reproducible workflow compilation and snapshot tests.

levels: Vec<Vec<String>>

The execution levels (parallel groups). Level 0 contains root nodes (no dependencies), Level 1 contains nodes that depend only on Level 0, etc.

roots: Vec<String>

Root node IDs (no dependencies).

leaves: Vec<String>

Leaf node IDs (no children).

Implementations

impl WorkflowDag

pub fn new(name: impl Into<String>) -> Self

Create an empty DAG.

pub fn add_node(&mut self, node: DagNode)

Add a node to the DAG.

pub fn build(&mut self)

Build the dependency edges and compute levels.

After all nodes are added, call this to:

1. Resolve depends_on → set children on parent nodes
2. Compute parallel levels via BFS
3. Identify root and leaf nodes

pub fn get_node(&self, id: &str) -> Option<&DagNode>

Get a node by ID.

pub fn node_count(&self) -> usize

Get the number of nodes.

pub fn level_count(&self) -> usize

Get the number of levels (parallel groups).

pub fn level_nodes(&self, level: usize) -> Vec<&DagNode>

Get nodes at a specific level.

pub fn topological_order(&self) -> Vec<String>

Get all node IDs in topological order (level 0 → level N).

pub fn has_cycle(&self) -> bool

Check if the DAG has any cycles.

Uses Kahn’s algorithm — if after removing all nodes with no dependencies, some nodes remain, there’s a cycle.

pub fn transitive_deps(&self, node_id: &str) -> HashSet<String>

Get all dependencies (transitive) of a 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<'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 PartialEq for WorkflowDag

fn eq(&self, other: &Self) -> bool

Equality operator ==.

fn ne(&self, other: &Rhs) -> bool

Inequality operator !=.

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.

impl StructuralPartialEq for WorkflowDag