Subject: Re: bug#31853: (27.0.50; binding case-fold-search is slow when there are many buffers)

From: Stefan Monnier <[email-masked]>
Date: Sat, 30 Jun 2018 09:18:23 -0400

> Is it possible to improve this somehow? In this instance it's actually
> org-mode that's binding case-fold-search in a tight loop in
> org-scan-tags.

BTW, I think that the idea that let-binding a dynamically-scoped var is
cheap is wrong.
It's basically only cheap when lexical-binding works as well ;-)

So regardless of whether we can speed it up like Eli did just now (by
only looping over the live buffers), the org-scan-tags code that
let-binds it within a tight loop should be fixed.

        Stefan