Re: Lexical binding: why?

[Dmitry Gutov]

On 28.05.2019 16:25, Stefan Monnier wrote:
> Maybe the speed up I remember was linked to the rework I suggested back
> then to work around the poor lexical-scoping performance (mainly moving
> a condition-case outside of a loop, IIRC) and that actually improved
> performance with both lexical and dynamic binding?

No, you remembered correctly: without the new byte-code, the situation 
was noticeably worse. Though maybe it was a 'throw' inside a loop with 
'catch' outside it.

The 10% figure I just got from this thread: 
https://github.com/mooz/js2-mode/issues/524#issuecomment-483010120

But it's actually comparing against an older js2-mode version, not 
against the current code in dynamic-binding mode. I don't have time to 
redo the measurements now myself, but thinking back, maybe the result of 
the byte-code introduction was that lexical-binding became slightly 
faster than dynamic, though not by much.