guile-data-structures/trees/simple-binary-tree/string-helpers.scm

(library (string-helpers)
  (export display-to-string
          string-repeat)
  (import (except (rnrs base))
          (only (guile)
                lambda*
                λ
                call-with-output-string
                display
                when))

  (define (string-repeat str n)
    (define (iter port str n)
      (when (> n 0)
        (display str port)
        (iter port str (- n 1))))

    (call-with-output-string
      (λ (port)
        (iter port str n))))


  (define display-to-string
    (λ (sth)
      (call-with-output-string
        (λ (port)
          (display sth port))))))