text-count.lisp

text-count.lisp

;; Constants

(defconstant *whitespace* '(#\space #\tab #\newline #\return))
(defconstant *separator* "EOF")


;; Predicates

(defun whitespace-p (char)
  "Returns a given character if it is whitespace, NIL otherwise."
  (find char *whitespace*))

(defun empty-line-p (line)
  "Returns T if a given line (string) is made up entirely of whitespace, NIL
  otherwise."
  (string= "" (remove-if #'whitespace-p line)))


;; Processing functions

(defun process-line (line)
  "Returns word count for a given line (string)."
  (unless (string= line *separator*)
      (if (empty-line-p line)
	  0
	  (1+ (count-if #'whitespace-p line)))))

(defun process-file (file)
  (with-open-file (in file)
    (do* ((line "" (read-line in nil))
	  (count-list '(0)
	    (let ((line-count (process-line line)))
	      (if line-count
		  (cons (+ (car count-list) line-count) (cdr count-list))
		  (cons 0 count-list)))))
	  ((not line) count-list))))


;; Wrappers

(defun word-count (file)
  (reverse (process-file file)))
 
(defun word-count-verbose (file)
  (let ((wch (process-file file)))
    (if (cdr wch)
	(let* ((wc1 (second wch))
	       (wc2 (first  wch))
	       (wct (+ wc1 wc2)))
	  (format t "~d/~d (~,1f%) words (~d remaining).~%"
		  wc1 wct (float (* 100 (/ wc1 wct))) wc2))
     	(format t "~a words.~%" (first wch)))))