Re: Overlay mechanic improvements

[Richard Stallman]

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    Because you don't want _anything_ that text properties do.  You don't
    want to have the stuff cut&paste,

Why not?  If the images are thought of as part of the buffer contents,
I'd expect it to be desirable that they follow text that is copied.
If you kill text that contains some of these images of math
and then yank  it back, shouldn't it come back with the images?

This is what lead me to think of text properties first for this job.

     you don't want to have the buffer
    modified because images are switched on and off,

We can provide a feature for turning off and on the display
of these images without changing the text properties themselves.
I think there already is a way.

                you don't want anything inserted anywhere inheriting
    anything from it.

We already have ways to specify no inheritance.

    you most definitely
    don't want ever to split its identity in two if there are insertions in
    the middle,

That's true.  However, isn't such insertion anomalous anyway?  How bad
is it, if that anomalous act causes the image to appear twice?

-- 
Dr Richard Stallman
President, Free Software Foundation
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