I am trying to write a series of guessing games in Lisp as a time-killing project. However, when I try to load a program using SBCL, I get the following error:
debugger invoked on a SB-C::INPUT-ERROR-IN-COMPILE-FILE in thread #<THREAD "initial thread" RUNNING {AA14959}>: READ failure in COMPILE-FILE at character 477: end of file on #<SB-SYS:FD-STREAM for "file /home/andy/Dropbox/Programming/Common Lisp/number-game.lisp" {B4F45F9}> Type HELP for debugger help, or (SB-EXT:QUIT) to exit from SBCL. restarts (invokable by number or by possibly-abbreviated name): 0: [CONTINUE] Ignore runtime option --load "number-game.lisp". 1: [ABORT ] Skip rest of --eval and --load options. 2: Skip to toplevel READ/EVAL/PRINT loop. 3: [QUIT ] Quit SBCL (calling #'QUIT, killing the process). (SB-C::READ-FOR-COMPILE-FILE #<SB-SYS:FD-STREAM for "file /home/andy/Dropbox/Programming/Common Lisp/number-game.lisp" {B4F45F9}> 477)
What does this error mean? The code is as follows, and an error appears when loading a file and calling (play) from REPL:
;;;; number-game.lisp ;;;; ;;;; Andrew Levenson ;;;; 10/25/2010 ;;;; ;;;; Simple number guessing game. User has ;;;; five guesses to determine a number between ;;;; one and one hundred, inclusive (1-100). ;;; Set global variable for the target number: (defparameter *target* nil) ;;; Set the iterator so we may check the number of guesses (defparameter *number-of-guesses* 0) ;;; Welcome the user (defun welcome-user () (format t "Welcome to the number guessing game!~%")) ;;; Prompt for a guess (defun prompt-for-guess () (format t "Please enter your guess (1-100): ") (finish-output nil) ; nil directs finish-output to standard IO (check-guess((read-guess))) ;;; Read in a guess (defun read-guess () (let ((guess (read))) (if (numberp guess) ; If true, return guess. Else, call prompt-for-guess (progn (setq *number-of-guesses* (+ *number-of-guesses* 1)) guess) (prompt-for-guess)))) ;;; Check if the guess is higher than, lower than, or equal to, the target (defun check-guess (guess) (if (equal guess *target*) (equal-to) (if (> guess *target*) (greater-than (guess)) (if (< guess *target*) (less-than (guess)))))) ;;; If the guess is equal to the target, the game is over (defun equal-to () (format t "Congratulations! You have guessed the target number, ~a!~%" *target*) (y-or-np "Play again? [y/n] ")) ;;; If the guess is greater than the target, inform the player. (defun greater-than (guess) (format t "Sorry, ~a is greater than the target.~%" guess) (if (< *number-of-guesses* 6) (prompt-for-guess) (game-over))) ;;; If the guess is less than the target, inform the player. (defun less-than (guess) (format t "Sorry, ~a is less than the target.~%" guess) (if (< *number-of-guesses* 6) (prompt-for-guess) (game-over))) ;;; If the player has run out of guesses, give them the option ;;; of playing the game again. (defun game-over () (y-or-np "You have run out of guesses. Play again? [y/n] ")) ;;; Play the game (defun play () ;; If it their first time playing this session, ;; make sure to greet the user. (unless (> *number-of-guesses* 0) (welcome-user)) ;; Reset their remaining guesses (setq *number-of-guesses* 0) ;; Set the target value (setq *target* ;; Random can return float values, ;; so we must round the result to get ;; an integer value. (round ;; Add one to the result, because ;; (random 100) yields a number between ;; 0 and 99, whereas we want a number ;; from 1 to 100 inclusive. (+ (random 100) 1))) (if (equal (prompt-for-guess) "y") (play) (quit)))
(I’m pretty sure that the program doesn’t work minus one error, I'm still a newbie when it comes to Lisp. This is only the first error that I encountered, I understood it myself.)
Oh, and the problem is most likely related to the prompt-for-guess , read-guess and check-guess functions, because these are the ones I was messing with when this error occurred.