;;; This file contains a general Common Lisp function for reading Lisp
;;; forms from an input file, and writing those forms, and their results
;;; to an output file. The output file need not exist beforehand.
;;;
;;; written by Kurt Krebsbach 4/9/87

(defun produce-output-file (in-file out-file)
 "Reads in forms, one at a time, from the in-file,
  writing both the form and the result of evaluating the form to the
  out-file"

(with-open-file (in-stream in-file :direction :input) 
 (with-open-file 
  (out-stream out-file :direction :output :if-exists :supersede)
  (do ((form (read in-stream nil 'eof-flag)          ; initial value
	     (read in-stream nil 'eof-flag)))        ; step value
      ((equal form 'eof-flag)                        ; termination test
       (format t "~%File ~A is written" out-file))   ; message
      (progn
       (format out-stream                            ; write the form
	       "~%Form:~%>>>>>~%~A~%" form) 
       (format out-stream 
	       "~%Result:~%<<<<<~%~A~%" (eval form)) ; write the result
       ))
  )))