(list->string chars)
Implements list->string as per ISO/IEC 10179:1996 (clause 8.5.9.9).
David Megginson, <dmeggins@uottawa.ca>
(define (list->string chars) ;; Converts a list of characters into a string (let loop ((cl chars) (str "")) (if (null? cl) str (loop (cdr cl) (string-append str (string (car cl)))))))