Adapter: Petgraph

fabula_petgraph -- wraps petgraph::StableGraph with temporal edges as a fabula DataSource.

Crate: fabula-petgraph

PetTemporalGraph<N, L, V, T>

A temporal graph backed by petgraph::StableGraph. Nodes are identified by N, edges carry TemporalEdge<L, V, T>. A HashMap<N, NodeIndex> provides reverse lookup from user IDs to petgraph's internal NodeIndex.

Edges are stored as self-loops on the source node. The target is stored in the edge weight's value field, not as a petgraph edge endpoint.

use fabula_petgraph::{PetTemporalGraph, PetValue, NodeRef};
use fabula::interval::Interval;

let mut g: PetTemporalGraph<String, String, PetValue<String>, i64>
    = PetTemporalGraph::new(0);
g.add_node("alice".into());
g.add_edge_to_node("ev1".into(), "actor".into(), "alice".into(), Interval::open(1));
g.add_edge("ev1".into(), "type".into(), PetValue::Str("harm".into()), Interval::open(1));
g.set_time(10);

Type parameters

Parameter	Bounds	Description
N	Eq + Hash + Clone + Debug	Node identifier type.
L	Eq + Hash + Clone + Debug	Edge label type.
V	PartialEq + PartialOrd + Clone + Debug	Value type. Use PetValue<N> for the default adapter.
T	Ord + Clone + Debug	Time type.

DataSource type mapping (with PetValue<N>)

Associated type	Concrete type
N	N
L	L
V	PetValue<N>
T	T

The DataSource implementation requires V = PetValue<N> and N: PartialOrd.

Methods

PetTemporalGraph::new

Creates a new empty graph with the given initial time.

pub fn new(initial_time: T) -> Self

Parameter	Type	Required	Default	Description
initial_time	T	yes	--	Initial current time.

Returns: PetTemporalGraph<N, L, V, T>

---

set_time

Sets the current time.

pub fn set_time(&mut self, t: T)

Parameter	Type	Required	Default	Description
t	T	yes	--	The new current time.

---

add_node

Adds a node, or returns the existing NodeIndex if already present.

pub fn add_node(&mut self, id: N) -> NodeIndex

Parameter	Type	Required	Default	Description
id	N	yes	--	Node identifier.

Returns: NodeIndex -- petgraph's internal node index.

---

add_edge

Adds a temporal edge from a node with an arbitrary value and interval.

pub fn add_edge(&mut self, from: N, label: L, value: V, interval: Interval<T>)

Parameter	Type	Required	Default	Description
from	N	yes	--	Source node ID. Created if it does not exist.
label	L	yes	--	Edge label.
value	V	yes	--	Target value.
interval	Interval<T>	yes	--	Validity interval.

---

add_edge_to_node

Adds a temporal edge with a node-valued target. Ensures the target node exists. Requires V: From<NodeRef<N>>.

pub fn add_edge_to_node(&mut self, from: N, label: L, to: N, interval: Interval<T>)

Parameter	Type	Required	Default	Description
from	N	yes	--	Source node ID.
label	L	yes	--	Edge label.
to	N	yes	--	Target node ID. Created if it does not exist.
interval	Interval<T>	yes	--	Validity interval.

---

add_edge_bounded

Adds a temporal edge with a bounded interval [start, end). Requires T: Ord.

pub fn add_edge_bounded(&mut self, from: N, label: L, value: V, start: T, end: T)

Parameter	Type	Required	Default	Description
from	N	yes	--	Source node ID.
label	L	yes	--	Edge label.
value	V	yes	--	Target value.
start	T	yes	--	Interval start (inclusive).
end	T	yes	--	Interval end (exclusive).

---

node_count

Returns the number of nodes.

pub fn node_count(&self) -> usize

Returns: usize

---

edge_count

Returns the number of edges.

pub fn edge_count(&self) -> usize

Returns: usize

---

TemporalEdge<L, V, T>

A temporal edge weight stored on a petgraph edge.

pub struct TemporalEdge<L, V, T> {
    pub label: L,
    pub value: V,
    pub interval: Interval<T>,
}

Field	Type	Description
label	L	Edge label.
value	V	Target value.
interval	Interval<T>	Validity interval.

Trait implementations

Debug, Clone.

---

NodeRef<N>

Wrapper to distinguish node references from other values. Used with From<NodeRef<N>> to convert node IDs into PetValue::Node.

pub struct NodeRef<N>(pub N);

Field	Type	Description
0	N	The node identifier.

Trait implementations

Debug, Clone.

---

PetValue<N>

A value type for the petgraph adapter. Holds node references or literals.

pub enum PetValue<N: Debug + Clone + PartialOrd> {
    Node(N),
    Str(String),
    Num(f64),
    Bool(bool),
}

Variant	Description
Node(N)	Reference to another node. value_as_node returns Some.
Str(String)	String literal.
Num(f64)	Numeric value.
Bool(bool)	Boolean value.

Trait implementations

Trait	Notes
Debug	Derived.
Clone	Derived.
PartialEq	Derived.
PartialOrd	Derived.
From<NodeRef<N>>	Converts NodeRef(n) to PetValue::Node(n).