FEAT: Add StableGraph::retain_edges
diff --git a/src/graph_impl/stable_graph/mod.rs b/src/graph_impl/stable_graph/mod.rs
index 9a1d1f6..e0db3d5 100644
--- a/src/graph_impl/stable_graph/mod.rs
+++ b/src/graph_impl/stable_graph/mod.rs
@@ -709,7 +709,7 @@
/// **e'** is the number of affected edges, including *n* calls to `.remove_edge()`
/// where *n* is the number of edges with an endpoint in a removed node.
pub fn retain_nodes<F>(&mut self, mut visit: F) where F: FnMut(Frozen<Self>, NodeIndex<Ix>) -> bool {
- for i in 0..self.g.node_count() {
+ for i in 0..self.node_bound() {
let ix = node_index(i);
if self.contains_node(ix) && !visit(Frozen(self), ix) {
self.remove_node(ix);
@@ -718,6 +718,31 @@
self.check_free_lists();
}
+ /// Keep all edges that return `true` from the `visit` closure,
+ /// remove the others.
+ ///
+ /// `visit` is provided a proxy reference to the graph, so that
+ /// the graph can be walked and associated data modified.
+ ///
+ /// The order edges are visited is not specified.
+ ///
+ /// The edge indices of the removed edes are invalidated, but none other.
+ /// Edge indices are invalidated as they would be following the removal of
+ /// each edge with an endpoint in a removed edge.
+ ///
+ /// Computes in **O(e'')** time, **e'** is the number of affected edges,
+ /// including the calls to `.remove_edge()` for each removed edge.
+ pub fn retain_edges<F>(&mut self, mut visit: F)
+ where F: FnMut(Frozen<Self>, EdgeIndex<Ix>) -> bool
+ {
+ for i in 0..self.edge_bound() {
+ let ix = edge_index(i);
+ if self.edge_weight(ix).is_some() && !visit(Frozen(self), ix) {
+ self.remove_edge(ix);
+ }
+ }
+ self.check_free_lists();
+ }
/// Create a new `StableGraph` from an iterable of edges.
///
