(require 'cl-ppcre)

(defparameter *wpm* 300)
(defparameter *chunk-size* 1)

(defun tokenize(str)
  (cl-ppcre:split "\\s+" str))

(defun lines(file)
  (with-open-file (in file
                      :direction :input
                      :if-does-not-exist :error)
    (loop for line = (read-line in nil)
       while line
       collect line)))

(defun concat(lst)
  (apply #'concatenate 'string lst))

(defun read-words(path)
  (tokenize (concat (lines path))))

(defun wpm-delay(n)
  (/ 60.0 n))

(defun rsvp(path wpm chunk)
  (let* ((book (read-words path))
         (ch chunk)
         (book-len (length book)))
	(do* ((n 0 (1+ ch))
	      (words book (nthcdr ch book)))
         ((>= ch (- book-len n))(print (subseq words n)))
      (print (subseq words n (+ n ch)))
      (sleep (wpm-delay wpm)))))