Testing in LISP is amazing

test.lisp

(defun make-edge (from ids &key end)
  (progn
    (setf ids (mklist ids)))
    (dolist (to ids)
      (let ((lst (gethash from *edges*)))
        (cond ((not lst)
               (setf (gethash from *edges*) (list to)))
              (t (if (not (member to lst))
                   (setf (gethash from *edges*) (append lst (list to)))))))
      (unless end (make-edge to from :end t)))))
; (make-edge 1 3)
; (make-edge 3 4)
; (make-edge 6 7)
; (make-edge 5 '(7 8 9))

(defun print-hash-entry (key value)
      (format t "The value associated with the key ~S is ~S~%" key value))
;; (maphash #'print-hash-entry *edges*)

(defun get-edges (id)
  (gethash id *edges*))
; (get-edges 1)

(defun get-node-edges (edges)
  (let ((lst '()))
    (dolist (e edges)
      (push (get-node e) lst))
    lst))
;; (get-node-edges (get-edges 1))