bug#2768: 23.0.60; Misleading function description for float-time

bug#2768: 23.0.60; Misleading function description for float-time

[David Kastrup]

Please write in English if possible, because the Emacs maintainers
usually do not have translators to read other languages for them.

Your bug report will be posted to the emacs-pretest-bug@gnu.org mailing list.

Please describe exactly what actions triggered the bug
and the precise symptoms of the bug:

The DOC string for float-time says

    float-time is a built-in function in `C source code'.

    (float-time &optional specified-time)

    Return the current time, as a float number of seconds since the epoch.
    If specified-time is given, it is the time to convert to float
    instead of the current time.  The argument should have the form
    (HIGH LOW . IGNORED). Thus, you can use times obtained from
    `current-time' and from `file-attributes'.  specified-time can also
    have the form (HIGH . LOW), but this is considered obsolete.

    WARNING: Since the result is floating point, it may not be exact.
    Do not use this function if precise time stamps are required.

    [back]


However, the argument "IGNORED" is not ignored but rather specifies
microseconds that _do_ appear in the resulting time value.  While the
doc string does not explicitly specify what happens to "IGNORED", its
name strongly suggests a different (and undesirable) behavior.

In GNU Emacs 23.0.60.2 (i686-pc-linux-gnu, GTK+ Version 2.12.9)
 of 2009-01-13 on lisa
Windowing system distributor `The X.Org Foundation', version 11.0.10400090
configured using `configure  '--prefix=/usr/local/emacs-21' '--without-toolkit-scroll-bars''

Important settings:
  value of $LC_ALL: nil
  value of $LC_COLLATE: nil
  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: Message

Minor modes in effect:
  mml-mode: t
  gnus-message-citation-mode: t
  TeX-PDF-mode: t
  server-mode: t
  desktop-save-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-composition-mode: t
  auto-encryption-mode: t
  auto-compression-mode: t
  line-number-mode: t
  transient-mark-mode: t
  abbrev-mode: t

-- 
David Kastrup

bug#2768: marked as done (23.0.60; Misleading function description for float-time)

[Emacs bug Tracking System]

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Your message dated Tue, 24 Mar 2009 13:40:04 -0400
with message-id <877i2eyg3v.fsf@cyd.mit.edu>
and subject line Re: 23.0.60; Misleading function description for float-time
has caused the Emacs bug report #2768,
regarding 23.0.60; Misleading function description for float-time
to be marked as done.

This means that you claim that the problem has been dealt with.
If this is not the case it is now your responsibility to reopen the
bug report if necessary, and/or fix the problem forthwith.

(NB: If you are a system administrator and have no idea what this
message is talking about, this may indicate a serious mail system
misconfiguration somewhere. Please contact owner@emacsbugs.donarmstrong.com
immediately.)


-- 
2768: http://emacsbugs.donarmstrong.com/cgi-bin/bugreport.cgi?bug=2768
Emacs Bug Tracking System
Contact owner@emacsbugs.donarmstrong.com with problems

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From: David Kastrup <dak@gnu.org>
To: emacs-pretest-bug@gnu.org
Subject: 23.0.60; Misleading function description for float-time
Date: Tue, 24 Mar 2009 11:04:31 +0100
Message-ID: <86zlfbck40.fsf@lola.quinscape.zz>


Please write in English if possible, because the Emacs maintainers
usually do not have translators to read other languages for them.

Your bug report will be posted to the emacs-pretest-bug@gnu.org mailing list.

Please describe exactly what actions triggered the bug
and the precise symptoms of the bug:

The DOC string for float-time says

    float-time is a built-in function in `C source code'.

    (float-time &optional specified-time)

    Return the current time, as a float number of seconds since the epoch.
    If specified-time is given, it is the time to convert to float
    instead of the current time.  The argument should have the form
    (HIGH LOW . IGNORED). Thus, you can use times obtained from
    `current-time' and from `file-attributes'.  specified-time can also
    have the form (HIGH . LOW), but this is considered obsolete.

    WARNING: Since the result is floating point, it may not be exact.
    Do not use this function if precise time stamps are required.

    [back]


However, the argument "IGNORED" is not ignored but rather specifies
microseconds that _do_ appear in the resulting time value.  While the
doc string does not explicitly specify what happens to "IGNORED", its
name strongly suggests a different (and undesirable) behavior.

In GNU Emacs 23.0.60.2 (i686-pc-linux-gnu, GTK+ Version 2.12.9)
 of 2009-01-13 on lisa
Windowing system distributor `The X.Org Foundation', version 11.0.10400090
configured using `configure  '--prefix=/usr/local/emacs-21' '--without-toolkit-scroll-bars''

Important settings:
  value of $LC_ALL: nil
  value of $LC_COLLATE: nil
  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: Message

Minor modes in effect:
  mml-mode: t
  gnus-message-citation-mode: t
  TeX-PDF-mode: t
  server-mode: t
  desktop-save-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-composition-mode: t
  auto-encryption-mode: t
  auto-compression-mode: t
  line-number-mode: t
  transient-mark-mode: t
  abbrev-mode: t

-- 
David Kastrup



[-- Attachment #3: Type: message/rfc822, Size: 1387 bytes --]

From: Chong Yidong <cyd@stupidchicken.com>
To: David Kastrup <dak@gnu.org>
Cc: 2768-done@emacsbugs.donarmstrong.com
Subject: Re: 23.0.60; Misleading function description for float-time
Date: Tue, 24 Mar 2009 13:40:04 -0400
Message-ID: <877i2eyg3v.fsf@cyd.mit.edu>

> the argument "IGNORED" is not ignored but rather specifies
> microseconds that _do_ appear in the resulting time value.  While the
> doc string does not explicitly specify what happens to "IGNORED", its
> name strongly suggests a different (and undesirable) behavior.

I've corrected this.  Thanks very much for pointing it out.