bug#679: 23.0.60; Function json-read-number does not handle complete Javascript spec

[ＯＦＦＩＣＥ ZERO <hi-oh230@air.ocn.ne.jp>]

Do'nt   send  me mail  !!!
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----- Original Message ----- 
From: <sand@blarg.net>
To: <emacs-pretest-bug@gnu.org>
Cc: <rfrancoise@debian.org>
Sent: Saturday, August 09, 2008 4:05 PM
Subject: bug#679: 23.0.60;Function json-read-number does not handle complete 
Javascript spec


> ----
>
> In json.el, the 'json-read-number' function is intended to read the
> textual representation of Javascript numbers.
>
> (defun json-read-number ()
>  "Read the JSON number following point.
> N.B.: Only numbers which can fit in Emacs Lisp's native number
> representation will be parsed correctly."
>  (if (char-equal (json-peek) ?-)
>      (progn
>        (json-advance)
>        (- 0 (json-read-number)))
>    (if (looking-at "[0-9]+\\([.][0-9]+\\)?\\([eE][+-]?[0-9]+\\)?")
>        (progn
>          (goto-char (match-end 0))
>          (string-to-number (match-string 0)))
>      (signal 'json-number-format (list (point))))))
>
> The Javascript spec
> (http://developer.mozilla.org/en/docs/Core_JavaScript_1.5_Guide:Literals#Floating-Point_Literals)
> says the following about floating-point numbers:
>
> | A floating-point literal can have the following parts:
> |
> |     * A decimal integer which can be signed (preceded by "+" or "-"),
> |     * A decimal point ("."),
> |     * A fraction (another decimal number),
> |     * An exponent.
> |
> | The exponent part is an "e" or "E" followed by an integer, which can
> | be signed (preceded by "+" or "-"). A floating-point literal must have
> | at least one digit and either a decimal point or "e" (or "E").
>
> This means that
>
>  1.
>
> is a valid floating point-literal per the spec, but the regular
> expression above does not match the complete text---the regular
> expression requires digits after the decimal point.  This ends up
> matched as a simple integer, leaving the decimal point in the input
> stream and causing a later syntax error.  Similarly
>
>  .1
>
> is a valid floating point-literal illegal that Emacs rejects, because
> the regular expression requires digits before the decimal point.
> Testing with the error console in Firefox confirms that the two
> examples above are valid syntax.
>
> The parser function needs to be fixed to handle the complete syntax.
>
> ----
>
>
> In GNU Emacs 23.0.60.1 (i486-pc-linux-gnu, GTK+ Version 2.12.11)
> of 2008-07-27 on elegiac, modified by Debian
> (emacs-snapshot package, version 1:20080727-1)
> Windowing system distributor `The X.Org Foundation', version 11.0.10402000
> configured using `configure  '--build' 'i486-linux-gnu' '--host' 
> 'i486-linux-gnu' '--prefix=/usr' '--sharedstatedir=/var/lib' 
> '--libexecdir=/usr/lib' '--localstatedir=/var' '--infodir=/usr/share/info' 
> '--mandir=/usr/share/man' '--with-pop=yes' 
> '--enable-locallisppath=/etc/emacs-snapshot:/etc/emacs:/usr/local/share/emacs/23.0.60/site-lisp:/usr/local/share/emacs/site-lisp:/usr/share/emacs/23.0.60/site-lisp:/usr/share/emacs/site-lisp' 
> '--with-x=yes' '--with-x-toolkit=gtk' 'build_alias=i486-linux-gnu' 
> 'host_alias=i486-linux-gnu' 
> 'CFLAGS=-DDEBIAN -DSITELOAD_PURESIZE_EXTRA=5000 -g -O2' 
> 'LDFLAGS=-g -Wl,--as-needed' 'CPPFLAGS=''
>
> Important settings:
>  value of $LC_ALL: nil
>  value of $LC_COLLATE: POSIX
>  value of $LC_CTYPE: nil
>  value of $LC_MESSAGES: nil
>  value of $LC_MONETARY: nil
>  value of $LC_NUMERIC: nil
>  value of $LC_TIME: nil
>  value of $LANG: en_US.UTF-8
>  value of $XMODIFIERS: nil
>  locale-coding-system: utf-8-unix
>  default-enable-multibyte-characters: t
>
> Major mode: VM
>
> Minor modes in effect:
>  shell-dirtrack-mode: t
>  auto-image-file-mode: t
>  show-paren-mode: t
>  icomplete-mode: t
>  tooltip-mode: t
>  mouse-wheel-mode: t
>  menu-bar-mode: t
>  file-name-shadow-mode: t
>  global-font-lock-mode: t
>  font-lock-mode: t
>  blink-cursor-mode: t
>  global-auto-composition-mode: t
>  auto-encryption-mode: t
>  auto-compression-mode: t
>  line-number-mode: t
>  transient-mark-mode: t
>
>
>
>