all messages for Emacs-related lists mirrored at yhetil.org
 help / color / mirror / code / Atom feed
* bug#679: 23.0.60; Function json-read-number does not handle complete Javascript spec
@ 2008-08-13  3:42 Chong Yidong
  2008-08-13  5:11 ` Edward O'Connor
  0 siblings, 1 reply; 9+ messages in thread
From: Chong Yidong @ 2008-08-13  3:42 UTC (permalink / raw)
  To: Edward O'Connor; +Cc: 679

Hi Edward,

Could you take a look at this bug report?

Thanks.

---------------

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.






^ permalink raw reply	[flat|nested] 9+ messages in thread
* bug#679: 23.0.60; Function json-read-number does not handle complete Javascript spec
@ 2008-08-09  7:05 sand
  2008-08-09 10:57 ` OFFICE ZERO
                   ` (2 more replies)
  0 siblings, 3 replies; 9+ messages in thread
From: sand @ 2008-08-09  7:05 UTC (permalink / raw)
  To: emacs-pretest-bug; +Cc: rfrancoise

----

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






^ permalink raw reply	[flat|nested] 9+ messages in thread

end of thread, other threads:[~2008-08-19  5:37 UTC | newest]

Thread overview: 9+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2008-08-13  3:42 bug#679: 23.0.60; Function json-read-number does not handle complete Javascript spec Chong Yidong
2008-08-13  5:11 ` Edward O'Connor
2008-08-14  2:25   ` Kevin Rodgers
2008-08-19  5:37     ` Edward O'Connor
2008-08-19  5:37     ` Edward O'Connor
  -- strict thread matches above, loose matches on Subject: below --
2008-08-09  7:05 sand
2008-08-09 10:57 ` OFFICE ZERO
2008-08-09 14:14 ` OFFICE ZERO
2008-08-13  3:11 ` Kevin Rodgers

Code repositories for project(s) associated with this external index

	https://git.savannah.gnu.org/cgit/emacs.git
	https://git.savannah.gnu.org/cgit/emacs/org-mode.git

This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.