Re: printing most-negative-fixnum fails

[Juri Linkov]

Peter Whaite <address@hidden> writes:
> Minor annoyance is that evaluating most-negative-fixnum in *scratch*
> (Lisp Interaction mode) fails...

This bug is caused by calling `(downcase most-negative-fixnum)'
in `event-modifiers' called from `prin1-char'.

I remember it was agreed some time ago that by default C-x C-e should
not display numbers as characters to avoid all related problems.

Below is a patch that introduces an option to control character display.

Also it is useful to display octal and hex values as well, like
for example, C-x = already does.

Index: emacs/lisp/emacs-lisp/lisp-mode.el
===================================================================
RCS file: /cvsroot/emacs/emacs/lisp/emacs-lisp/lisp-mode.el,v
retrieving revision 1.155
diff -u -w -b -r1.155 lisp-mode.el
--- emacs/lisp/emacs-lisp/lisp-mode.el  22 Mar 2004 15:31:46 -0000      1.155
+++ emacs/lisp/emacs-lisp/lisp-mode.el  10 May 2004 22:42:32 -0000
@@ -519,18 +521,25 @@
                         expr)))))))
       (eval-last-sexp-print-value value))))
 
+(defvar eval-last-sexp-print-char nil
+  "*Non-nil means display the result of evaluation as a character.")
+
 (defun eval-last-sexp-print-value (value)
   (let ((unabbreviated (let ((print-length nil) (print-level nil))
                         (prin1-to-string value)))
        (print-length eval-expression-print-length)
        (print-level eval-expression-print-level)
-       (char-string (prin1-char value))
        (beg (point))
        end)
     (prog1
        (prin1 value)
-      (if (and (eq standard-output t) char-string)
-         (princ (concat " = " char-string)))
+      (when (eq standard-output t)
+        (if (integerp value)
+            (princ (format " (0%o, 0x%x)" value value)))
+        (if eval-last-sexp-print-char
+            (let ((char-string (prin1-char value)))
+              (if char-string
+                  (princ (concat " = " char-string))))))
       (setq end (point))
       (when (and (bufferp standard-output)
                 (or (not (null print-length))

Index: emacs/lisp/emacs-lisp/edebug.el
===================================================================
RCS file: /cvsroot/emacs/emacs/lisp/emacs-lisp/edebug.el,v
retrieving revision 3.67
diff -u -w -b -r3.67 edebug.el
--- emacs/lisp/emacs-lisp/edebug.el     22 Mar 2004 15:27:46 -0000      3.67
+++ emacs/lisp/emacs-lisp/edebug.el     10 May 2004 22:42:31 -0000
@@ -3692,8 +3692,11 @@
   (setq edebug-previous-result
        (concat "Result: "
                (edebug-safe-prin1-to-string edebug-previous-value)
+                (if (integerp edebug-previous-value)
+                    (format " (0%o, 0x%x)" edebug-previous-value 
edebug-previous-value))
+               (if eval-last-sexp-print-char
                (let ((name (prin1-char edebug-previous-value)))
-                 (if name (concat " = " name))))))
+                 (if name (concat " = " name)))))))
 
 (defun edebug-previous-result ()
   "Print the previous result."

-- 
Juri Linkov
http://www.jurta.org/emacs/