Prepare release 0.21.0

CHANGELOG.md

@@ -5,6 +5,14 @@ All notable changes to this project will be documented in this file.
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),  and this project
 adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
+## [0.21.0] - 2023-05-18
+
+### Added
+* Added the `BFSWithDepth` function for performing a BFS with depth information.
+
+### Fixed
+* Fixed false positives of `ErrVertexHasEdges` when removing a vertex.
+
 ## [0.20.0] - 2023-05-01
 
 **Release post: [graph Version 0.20 Is Out](https://dominikbraun.io/blog/graph-version-0.20-is-out/)**

traversal.go

@@ -105,6 +105,17 @@ func BFS[K comparable, T any](g Graph[K, T], start K, visit func(K) bool) error
 	return BFSWithDepth(g, start, ignoreDepth)
 }
 
+// BFSWithDepth works just as BFS and performs a breadth-first search on the graph, but its
+// visit function is passed the current depth level as a second argument. Consequently, the
+// current depth and be used for deciding whether or not to proceed past a certain depth.
+//
+//	_ = graph.BFSWithDepth(g, 1, func(value int, depth int) bool {
+//		fmt.Println(value)
+//		return depth > 3
+//	})
+//
+// With the visit function from the example, the BFS traversal will stop once a depth greater
+// than 3 is reached.
 func BFSWithDepth[K comparable, T any](g Graph[K, T], start K, visit func(K, int) bool) error {
 	adjacencyMap, err := g.AdjacencyMap()
 	if err != nil {