Re: Tracking buffer positions across time, without markers (was Re: PL support)

[Clément Pit-Claudel]

On 09/05/2020 19.26, João Távora wrote:
> This is done with an idle timer, much the way that Flycheck
> works, I believe. 

Yup, it's a longstanding issue in Flycheck ^^

> > A bit.  But this works only if the interaction is fast enough, right? (Same 
> > for syntax errors: positions may well be outdated by the time the errors 
> > come back)

> By that time another request is probably already underway.

As long as the requests are fast.  With slow checkers (typically, proof 
assistants and automated reasoning tools, a single query can easily take a 
minute — by that point lots can have changed in a buffer.

The APIs that make this work in Visual Studio (spans and snapshots) are 
described here: 
https://docs.microsoft.com/en-us/visualstudio/extensibility/inside-the-editor?view=vs-2019

I'd love to hear opinions on what the proper implementation of this would for 
Emacs be.