(defun map-shortest-paths
(graph start-vertex depth fn &key (filter (constantly t)))
"Apply fn to each shortest path starting at `start-vertex` of depth `depth`. The `filter` predicate is used to remove vertexes from consideration."
- (bind ((visited (make-container 'simple-associative-container
+ (let ((visited (make-container 'simple-associative-container
:test #'equal)))
(labels ((visit (p)
(setf (item-at-1 visited p) t))