#lang scheme
(require scheme/string)

(define (chunky li sz [str ""])
  (let ([graft (lambda (s l) 
                 (string-append s (string-join l " ") "\n"))])
    (if [<= (length li) sz]
      (graft str li)
      (let-values ([(x y) (split-at li sz)])
        (chunky y sz (graft str x))))))

(display (chunky '("a" "bb" "c" "d" "e" "f" "g" "h") 3))
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+% mzscheme chunky.ss
a bb c
d e f
g h
+%
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