Struct TaskGraph 

pub struct TaskGraph { /* private fields */ }

Task dependency graph

Wraps petgraph DiGraph to provide task-specific operations. Nodes are Tasks, edges are DependencyEdge relationships.

Implementations

impl TaskGraph

pub fn new() -> Self

Create a new empty task graph

pub fn add_task(&mut self, task: Task) -> NodeIndex

Add a task to the graph

Returns the node index for the added task.

pub fn add_dependency(&mut self, task_a_id: &str, task_b_id: &str) -> Result<()>

Add a dependency: task_a blocks task_b (b depends on a)

Returns error if either task ID not found.

pub fn topological_sort(&self) -> Result<Vec<String>>

Perform topological sort

Returns tasks in valid execution order (dependencies first). Returns error if graph contains cycles.

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

Detect cycles in the graph

Returns list of cycles, where each cycle is a list of task IDs. Empty list means no cycles (valid DAG).

pub fn critical_path(&self) -> Result<Vec<String>>

Calculate critical path (longest path in DAG)

Returns list of task IDs on the critical path. Critical path represents the bottleneck (minimum time to complete all tasks).

Uses task duration estimates if available, otherwise treats all tasks as duration=1.

pub fn get_task(&self, task_id: &str) -> Option<&Task>

Get task by ID

pub fn tasks(&self) -> Vec<&Task>

Get all tasks

pub fn dependencies(&self, task_id: &str) -> Vec<String>

Get dependencies for a task (tasks that this task depends on)

pub fn dependents(&self, task_id: &str) -> Vec<String>

Get dependents for a task (tasks that depend on this task)

pub fn len(&self) -> usize

Number of tasks in graph

pub fn is_empty(&self) -> bool

Check if graph is empty

Trait Implementations

impl Default for TaskGraph

fn default() -> Self

Returns the “default value” for a type.