diff options
| -rw-r--r-- | utilities.lisp | 6 |
1 files changed, 5 insertions, 1 deletions
diff --git a/utilities.lisp b/utilities.lisp index 972df8a..214189f 100644 --- a/utilities.lisp +++ b/utilities.lisp @@ -38,7 +38,11 @@ "Creates a new list, the result of inserting X into the Nth position of LIST, displacing the rest of the elements by one position. If N is greater than the length of LIST, X becomes the last element of - LIST. If N is negative, a list containing just X is returned." + LIST. If N is negative, the element is inserted from the back of + the list. If the abslute value of -N is greater than the lenght of + the list, a list just containing X is returned." + (when (minusp n) + (setf n (+ 1 n (length list)))) (multiple-value-bind (front back) (take n list) ;; NCONC ok b/c this call to TAKE returns values that do not shre ;; memory with LIST |