Struct HeteroGraph 

pub struct HeteroGraph { /* private fields */ }

A heterogeneous graph with multiple node and edge types.

Node identifiers

All nodes share a single global NodeId namespace. Use HeteroGraph::add_node to assign a node to a particular type; the returned NodeId is globally unique.

Edge types

Edges are grouped by HeteroEdgeType. Each group is an unordered list of (src_id, dst_id) pairs; duplicate edges are allowed (useful for multigraphs).

Example

use scirs2_graph::heterogeneous::HeteroGraph;

let mut g = HeteroGraph::new();
let u0 = g.add_node("user", 0).unwrap();
let i0 = g.add_node("item", 0).unwrap();
g.add_edge("user", "buys", "item", u0, i0).unwrap();

assert_eq!(g.node_count(), 2);
assert_eq!(g.edge_count(), 1);

Implementations

impl HeteroGraph

pub fn new() -> Self

Create an empty heterogeneous graph.

pub fn add_node( &mut self, type_name: impl Into<String>, _hint: usize, ) -> Result<NodeId>

Register a new node of type type_name.

_hint is an optional user-supplied integer label (e.g. a database primary key); it is stored purely for user convenience and does not affect the global NodeId that is returned.

Errors

Returns GraphError::InvalidParameter if type_name is empty.

pub fn add_edge( &mut self, src_type: impl Into<String>, relation: impl Into<String>, dst_type: impl Into<String>, src_id: NodeId, dst_id: NodeId, ) -> Result<()>

Add a directed typed edge src_id --relation--> dst_id.

Both nodes must already be present in the graph and must belong to src_type and dst_type respectively.

Errors

• GraphError::NodeNotFound – node not registered.
• GraphError::InvalidParameter – node belongs to the wrong type.

pub fn node_count(&self) -> usize

Total number of registered nodes (across all types).

pub fn edge_count(&self) -> usize

Total number of registered edges (across all edge types).

pub fn node_type_names(&self) -> Vec<&str>

List all node types present in the graph.

pub fn edge_type_list(&self) -> Vec<&HeteroEdgeType>

List all edge types present in the graph.

pub fn nodes_of_type(&self, type_name: &str) -> &[NodeId]

Return the nodes belonging to type_name.

pub fn type_of(&self, node: NodeId) -> Option<&str>

Return the type name of a node.

pub fn edges_of_type(&self, et: &HeteroEdgeType) -> &[(NodeId, NodeId)]

Return all edges of a specific HeteroEdgeType.

Returns an empty slice if the edge type has no edges.

pub fn out_neighbors_typed( &self, node: NodeId, et: &HeteroEdgeType, ) -> Vec<NodeId>

Return the out-neighbours of node under a specific edge type.

Complexity: O(number of edges of that type).

pub fn all_out_neighbors_typed( &self, node: NodeId, ) -> Vec<(&HeteroEdgeType, Vec<NodeId>)>

Return all (edge_type, neighbours) pairs for node.

Useful for heterogeneous message passing.

pub fn contains_node(&self, node: NodeId) -> bool

Check whether a node is registered in the graph.

pub fn has_typed_edge( &self, et: &HeteroEdgeType, src: NodeId, dst: NodeId, ) -> bool

Check whether a typed edge exists.

Trait Implementations

impl Clone for HeteroGraph

fn clone(&self) -> HeteroGraph

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for HeteroGraph

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

Formats the value using the given formatter.

impl Default for HeteroGraph

fn default() -> Self

Returns the “default value” for a type.