Repeat string/character with (format)

Question

Is there a repeat directive for (format) in Common lisp, something like(I know this won't work):

(format t "~5C" #\*)

Just wondering if there isn't a more elegant way to do it than this:(from rosettacode )

(defun repeat-string (n string)
  (with-output-to-string (stream)
    (loop repeat n do (write-string string stream))))

(princ (repeat-string 5 "hi"))

Answer 1

(defun write-repeated-string (n string stream)
  (loop repeat n do (write-string string stream)))

(write-repeated-string 5 "hi" *standard-output*))

Generally you can use the format iteration:

(format t "~v@{~A~:*~}" 5 "hi")

~A can output all kinds of items, not just characters. For more information see uselpa's linked answers.

Above takes the iteration number from the first argument. Thus the v behind the tilde.

The rest of the arguments will be consumed by the iteration. Thus the @.

Inside the iteration we go back one element. Thus ~:*.

It's similar to (format t "~v{~A~:*~}" 5 '("hi")), which might be simpler to understand.