Re: Overlays as an AA-tree

[Joakim Jalap]

Andreas Politz <address@hidden> writes:

> Joakim Jalap <address@hidden> writes:
>
>> Andreas Politz <address@hidden> writes:
>>
>>> [...] wading through the current overlay code [...]
>
>> FWIW I've allready all this boring stuff. I you want you can look at my
>> branch at https://github.com/jockej/emacs-mirror2 branch
>> arne-without-parent.
>
> I already did, although briefly.  I think its even in the upstream repository 
> (?).

Which upstream repository are we talking about?

>> The interface is always the same*: Gather all the interesting overlays in
>> a vector. [...]
>
> Yes, but I'm trying to get a little bit behind that.  For example there
> is a common idiom of
>
> 1. gather overlays in a vector
> 2. sort by prioriy
> 3. determine the effective value of some property at some position

Actually I think 2 is not that common. Anyway I decided to keep the
existing function for sorting overlays, since that seemed simpler.

> So there should be a function answering question No. 3 without necessarily 
> going
> through steps 1 and 2 .

I think I have done that. For example there are the next_ptr and
prev_ptr arguments to overlays_at. I got rid of those and instead
introduced separat functions to find next overlay start/end. I also got
rid of the extend argument to overlays_at and friends. In my version the
vector is always extended if necessary.

Anyway, I will leave you to it.

-- Joakim