Re: Fwd: overlay face property not used for after-string property

[Joe Wells <jbw@macs.hw.ac.uk>]

Richard Stallman <rms@gnu.org> writes:

>     I think this information may not be enough.  I think the policy
>     would also need to know which of the overlay properties
>     before-string, display, or after-string the string comes from.
>
> In most cases you can determine this by looking at the overlay's
> properties and seeing where the string appears.  That will work except
> when the overlay has two properties that contain strings that are eq.

This would be a real pain.  What if the string being displayed is a
display property on the before-string?  You have to not just check all
3 of before-string, display, and after-string overlay properties, but
you also have to scan through both the before-string and after-string
properties looking for display text properties.

(By the way, in a separate message, I have complained about a bug that
strikes when eq strings are used in distinct display properties.)

> That is not good enough for the final implementation, but it is good
> enough for experimenting to find the right criteria.

I don't think it is good enough even for experimenting, for the reason
I indicate above.

> If the right
> criteria really depend on this information, we can add a mechanism to
> provide the information efficiently and reliably.  So I see no need to
> do that until we know whether it is needed.

-- 
Joe