[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: Loading files at startup (desktop) and revert-buffer leave buffers *
From: |
Alan Mackenzie |
Subject: |
Re: Loading files at startup (desktop) and revert-buffer leave buffers **. |
Date: |
Mon, 25 Nov 2002 22:45:57 +0000 |
User-agent: |
tin/1.4.5-20010409 ("One More Nightmare") (UNIX) (Linux/2.0.35 (i686)) |
Kevin Rodgers <kevinr@ihs.com> wrote on Mon, 25 Nov 2002 10:02:46 -0700:
> Changing Text Properties
> ------------------------
> The primitives for changing properties apply to a specified range of
> text. The function `set-text-properties' (see end of section) sets the
> entire property list of the text in that range; more often, it is
> useful to add, change, or delete just certain properties specified by
> name.
> Since text properties are considered part of the buffer's
> contents,....
This rather begs the question I was asking. _Why_ should text properties
be considered part of the buffer's contents? This isn't a rhetorical
question. The way it is at the moment has sent at least one elisp
programmer (me) into a 4-month long confusion. In the end, I had to
enclose t-p changes inside a macro which restores the buffer-modified
flag at the end. font-lock, and its various ancillary modes, does the
same. This is a big hassle.
Eli has pointed out a mode (enriched-mode), where t-p changes _are_
reflected in the eventual file contents, but I suspect this is a rare
thing in elisp code.
> .... and can affect how the buffer looks on the screen, any change in
> the text properties is considered a buffer modification. Buffer text
> property changes are undoable (*note Undo::.).
Handy thing, that undo!
It seems to me that one should only be prompted to save a buffer to a
file (e.g. on C-x C-s, or C-x k) when one has changed the substance of
that buffer, not merely the way it has been displayed. What is the
rationale behind prompting a user to save a "changed" file, merely
because he has changed its display within emacs to yellow letters, for
example? The same goes for the two stars displayed on the mode-line.
Maybe there should be two distinct change flags. A "user" change flag
when essential changes are made to the buffer, and an "internal" change
flag, to be used for buffer changes which can have no effect outside of
emacs.
--
Alan Mackenzie (Munich, Germany)
Email: aacm@muuc.dee; to decode, wherever there is a repeated letter
(like "aa"), remove half of them (leaving, say, "a").