Struct RuleDependencyGraph 

pub struct RuleDependencyGraph {
    pub rules: HashSet<String>,
    pub deps: Vec<RuleDependency>,
}

A directed graph that records dependencies between rules and can derive a safe topological evaluation order.

Nodes are rule IDs (plain Strings kept in a HashSet for O(1) membership tests). Edges are RuleDependency values stored in a Vec.

Invariants

• Both endpoints of every RuleDependency must already be registered via add_rule before the edge can be added.
• Duplicate rule IDs are rejected with DepError::DuplicateRule.

Fields

rules: HashSet<String>

Set of registered rule IDs.

deps: Vec<RuleDependency>

All dependency edges.

Implementations

impl RuleDependencyGraph

pub fn new() -> Self

Create an empty graph.

pub fn add_rule(&mut self, id: &str) -> Result<(), DepError>

Register a new rule.

Errors

Returns DepError::DuplicateRule if a rule with the same ID is already present.

pub fn add_dependency( &mut self, from: &str, to: &str, dep_type: DependencyType, ) -> Result<(), DepError>

Add a directed dependency edge from → to (meaning from depends on to).

Errors

Returns DepError::DependencyEndpointMissing if either endpoint has not been registered.

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

Compute a topological ordering of all registered rules using Kahn’s algorithm.

The ordering guarantees that for every dependency edge from → to, to appears before from in the returned vector.

Errors

Returns DepError::CycleDetected if the graph contains a cycle.

pub fn dependencies_of(&self, rule_id: &str) -> Vec<String>

Return the IDs of rules that rule_id directly depends on (i.e. the to endpoints of all edges whose from is rule_id).

pub fn dependents_of(&self, rule_id: &str) -> Vec<String>

Return the IDs of rules that directly depend on rule_id (i.e. the from endpoints of all edges whose to is rule_id).

pub fn has_cycle(&self) -> bool

Return true if the dependency graph contains at least one cycle.

pub fn rule_count(&self) -> usize

Return the number of registered rules.

pub fn dep_count(&self) -> usize

Return the number of dependency edges.

Trait Implementations

impl Debug for RuleDependencyGraph

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

Formats the value using the given formatter.

impl Default for RuleDependencyGraph

fn default() -> RuleDependencyGraph

Returns the “default value” for a type.