Re: Overlays as an AA-tree

[Eli Zaretskii]

> From: Andreas Politz <address@hidden>
> Date: Wed, 08 Feb 2017 08:34:01 +0100
> Cc: Stefan Monnier <address@hidden>, address@hidden
> 
> 1. gather overlays in a vector
> 2. sort by prioriy
> 3. determine the effective value of some property at some position

For some very popular overlay properties, (3) is not meaningful.
Examples includes the 'face' properties, whose values are merged
rather than using only the "effective value" determined by sorting;
and before- and after-strings, for which the sorting order determines
only the order in which the strings are rendered on display.