(Nils' Scheme Snippets)

(read-line . port) => string

(read-line) hello, world => " hello, world"

(define (read-line . port)
  (letrec
    ((collect-chars
       (lambda (c s)
         (cond
           ((eof-object? c)
             (if (null? s) c (list->string (reverse s))))
           ((char=? c #\newline)
             (list->string (reverse s)))
           (else (collect-chars (apply read-char port)
                                (cons c s)))))))
    (collect-chars (apply read-char port) '())))