Move more connected components functions to retworkx-core

rustworkx-core/src/connectivity/conn_components.rs

@@ -9,14 +9,16 @@
 // WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
 // License for the specific language governing permissions and limitations
 // under the License.
-
 use hashbrown::HashSet;
+use petgraph::algo;
 use std::collections::VecDeque;
 use std::hash::Hash;
-
-use petgraph::visit::{GraphProp, IntoNeighborsDirected, IntoNodeIdentifiers, VisitMap, Visitable};
+// use super::digraph;
+use petgraph::visit::{
+    GraphProp, IntoNeighborsDirected, IntoNodeIdentifiers, NodeCount, NodeIndexable, VisitMap,
+    Visitable,
+};
 use petgraph::{Incoming, Outgoing};
-
 /// Given an graph, a node in the graph, and a visit_map,
 /// return the set of nodes connected to the given node
 /// using breadth first search and treating all edges
@@ -165,6 +167,33 @@ where
     num_components
 }
 
+pub fn is_connected<G>(graph: G) -> bool
+where
+    G: GraphProp
+        + IntoNeighborsDirected
+        + Visitable
+        + IntoNodeIdentifiers
+        + NodeIndexable
+        + NodeCount,
+    G::NodeId: Eq + Hash,
+{
+    match graph.node_identifiers().next() {
+        Some(node) => {
+            let component = node_connected_component(graph, node.to_index());
+            component.len() == graph.node_count()
+        }
+        None => false,
+    }
+}
+
+pub fn node_connected_component<G>(graph: G, node: G::NodeId) -> HashSet<G::NodeId>
+where
+    G: GraphProp + IntoNeighborsDirected + Visitable + IntoNodeIdentifiers,
+    G::NodeId: Eq + Hash,
+{
+    bfs_undirected(&graph, node, &mut graph.visit_map())
+}
+
 #[cfg(test)]
 mod test_conn_components {
     use hashbrown::HashSet;

rustworkx-core/src/connectivity/mod.rs

@@ -22,4 +22,6 @@ pub use biconnected::articulation_points;
 pub use chain::chain_decomposition;
 pub use conn_components::bfs_undirected;
 pub use conn_components::connected_components;
+pub use conn_components::is_connected;
+// pub use conn_components::node_connected_components;
 pub use conn_components::number_connected_components;

src/connectivity/mod.rs

@@ -261,20 +261,7 @@ pub fn connected_components(graph: &graph::PyGraph) -> Vec<HashSet<usize>> {
 #[pyfunction]
 #[pyo3(text_signature = "(graph, node, /)")]
 pub fn node_connected_component(graph: &graph::PyGraph, node: usize) -> PyResult<HashSet<usize>> {
-    let node = NodeIndex::new(node);
-
-    if !graph.graph.contains_node(node) {
-        return Err(InvalidNode::new_err(
-            "The input index for 'node' is not a valid node index",
-        ));
-    }
-
-    Ok(
-        connectivity::bfs_undirected(&graph.graph, node, &mut graph.graph.visit_map())
-            .into_iter()
-            .map(|x| x.index())
-            .collect(),
-    )
+    connectivity::node_connected_component(&graph.graph, node)
 }
 
 /// Check if the graph is connected.
@@ -288,13 +275,7 @@ pub fn node_connected_component(graph: &graph::PyGraph, node: usize) -> PyResult
 #[pyfunction]
 #[pyo3(text_signature = "(graph, /)")]
 pub fn is_connected(graph: &graph::PyGraph) -> PyResult<bool> {
-    match graph.graph.node_indices().next() {
-        Some(node) => {
-            let component = node_connected_component(graph, node.index())?;
-            Ok(component.len() == graph.graph.node_count())
-        }
-        None => Err(NullGraph::new_err("Invalid operation on a NullGraph")),
-    }
+    connectivity::is_connected(&graph.graph)
 }
 
 /// Find the number of weakly connected components in a directed graph