unclear doc for existence of mark

[Drew Adams]

emacs -Q
C-h i, choose Elisp manual, g Mark

This text is not clear:

 Each buffer has its own value of the mark that is independent of the
 value of the mark in other buffers.  When a buffer is created, the mark
 exists but does not point anywhere.  We consider this state as "the
 absence of a mark in that buffer."

 Once the mark "exists" in a buffer, it normally never ceases to exist.

The notion of mark existence is unclear here. In a virgin buffer, it
says, the mark exists.  Yet, in this state the mark is "absent".  So,
the last sentence presumably wants to talk about lack of "absence"
(i.e. presence), rather than existence.  Otherwise, it contradicts the
first statement that the mark exists from the beginning, as well as
its own statement that the mark never ceases to exist (if it has
always existed and it always will exist, then "once the mark 'exists'"
says nothing useful.

The first statement, that the mark exists from the beginning but
points nowhere, could be kept as the consistent point of view
throughout, but that is not currently the case.  In that case, instead
of "absence" and then, later, "existence" (presence), we would speak
of the mark pointing nowhere and then pointing somewhere.

Alternatively, the starting point of the explanation could be changed,
to say that in the beginning the mark does not exist. The rest would
follow more or less as is, with non-existence/existence replacing
absence/presence (no need for two terms, which increases confusion).

Either of these approaches would be consistent; the current text is
not consistent, and is confusing.

My own preference is the second alternative: Don't say that the mark
exists from the beginning. We might want to introduce the function
`mark' here, saying that when (mark t) returns nil it means that the
mark does not yet exist - that is, it indicates that virgin state.

Also, quotation marks should not be used in this text, in any case -
they add nothing but more confusion. New terms that are defined can be
put in a different font (e.g. bold), but should not be between
quotation marks. I don't know what the Emacs doc convention is on
this. In any case, even if the Emacs doc convention were to quote the
defining occurrence of a new term, the sections quoted here should not
be quoted. In that case, only "absence" would be quoted. Certainly,
"exists" should not be quoted in the last sentence cited.


In GNU Emacs 22.0.93.1 (i386-mingw-nt5.1.2600)
 of 2007-01-25 on LENNART-69DE564
X server distributor `Microsoft Corp.', version 5.1.2600
configured using `configure --with-gcc (3.4) --cflags -Ic:/g/include'

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: ENU
  locale-coding-system: cp1252
  default-enable-multibyte-characters: t

Major mode: Dired by name

Minor modes in effect:
  encoded-kbd-mode: t
  tooltip-mode: t
  tool-bar-mode: t
  mouse-wheel-mode: t
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  file-name-shadow-mode: t
  global-font-lock-mode: t
  font-lock-mode: t
  blink-cursor-mode: t
  unify-8859-on-encoding-mode: t
  utf-translate-cjk-mode: t
  auto-compression-mode: t
  line-number-mode: t

Recent input:
<help-echo> <help-echo> <help-echo> <help-echo> <help-echo>
<help-echo> <help-echo> <menu-bar> <help-menu> <re
port-emacs-bug>

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