The follwoing codes are from "Practical Common Lisp" :
(defvar *db* nil)
(defun make-cd (title artist rating ripped)
(list :title title :artist artist :rating rating :ripped ripped))
(defun add-record (cd) (push cd *db*))
(defun dump-db ()
(format t "~{~{~a:~10t~a~%~}~%~}" *db*))
(defun prompt-read (prompt)
(format *query-io* "~a: " prompt)
(force-output *query-io*)
(read-line *query-io*))
(defun prompt-for-cd ()
(make-cd
(prompt-read "Title")
(prompt-read "Artist")
(or (parse-integer (prompt-read "Rating") :junk-allowed t) 0)
(y-or-n-p "Ripped [y/n]: ")))
under gcl-2.6.6 , the function call of (prompt-for-cd) gets the
following responses:
dbl:>>
(prompt-for-cd)
Title: Artist: 1 2
^^^^^^^^^^^^^
Rating: 3
Ripped [y/n]: (Y or N) y
(:TITLE "" :ARTIST "1 2" :R ...
The words "Title:" and "Artist:" appear in the same line ,
that's an obvious error.
The same lisp codes run on CLISP-2.34 and return as below:
[7]> (prompt-for-cd)
Title: 1
Artist: 2
Rating: 3
Ripped [y/n]: (y/n) 4
Please answer with y or n : y
(:TITLE "1" :ARTIST "2" :RATING 3 :RIPPED T)
Can anyone tell me what error is in GNU common lisp ?
Greetings, and thanks for this report!
You've found a bug in our reader apparently. The newline following
the invocation of (prompt-for-cd) is not read from the stream when
'(prompt-for-cd) is read, and is hence left on the stream for reading
when prompt-for-cd is evaluated.
Its an easy fix provided one knows what the right thing to do is.
Should readers always swallow trailing whitespace when invoked at
top-level and without being invoked via read-preserving-whitespace?
If you want to test more of this, just add a (read-line) before the
(make-cd ...) in the prompt-for-cd function definition for now.
Take care,
··········@bbs.ee.ncu.edu.tw writes:
> The follwoing codes are from "Practical Common Lisp" :
> (defvar *db* nil)
>
> (defun make-cd (title artist rating ripped)
> (list :title title :artist artist :rating rating :ripped ripped))
>
> (defun add-record (cd) (push cd *db*))
>
> (defun dump-db ()
> (format t "~{~{~a:~10t~a~%~}~%~}" *db*))
>
> (defun prompt-read (prompt)
> (format *query-io* "~a: " prompt)
> (force-output *query-io*)
> (read-line *query-io*))
>
> (defun prompt-for-cd ()
> (make-cd
> (prompt-read "Title")
> (prompt-read "Artist")
> (or (parse-integer (prompt-read "Rating") :junk-allowed t) 0)
> (y-or-n-p "Ripped [y/n]: ")))
>
> under gcl-2.6.6 , the function call of (prompt-for-cd) gets the
> following responses:
> dbl:>>
> (prompt-for-cd)
> Title: Artist: 1 2
> ^^^^^^^^^^^^^
> Rating: 3
>
> Ripped [y/n]: (Y or N) y
>
> (:TITLE "" :ARTIST "1 2" :R ...
>
> The words "Title:" and "Artist:" appear in the same line ,
> that's an obvious error.
> The same lisp codes run on CLISP-2.34 and return as below:
> [7]> (prompt-for-cd)
> Title: 1
> Artist: 2
> Rating: 3
> Ripped [y/n]: (y/n) 4
> Please answer with y or n : y
> (:TITLE "1" :ARTIST "2" :RATING 3 :RIPPED T)
>
> Can anyone tell me what error is in GNU common lisp ?
>
--
Camm Maguire ····@enhanced.com
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