bug#31138: Native json slower than json.el

[Dmitry Gutov]

On 25.04.2019 13:44, Eli Zaretskii wrote:

> > > Why faster?
> >
> > Because the library will perform its validation anyway, during normal
> > execution.
>
> But if we validate the string before even calling the library, that
> will be even faster, no?

Only if the string is invalid. There's not much point in optimizing for 
that situation, I think.

> > Any extra validation work Emacs performs, will take time on
> > top of that (of course, I don't know how much time).
>
> Didn't we just establish that it's almost negligible?  Especially for
> short strings?

Probably. But I can't say for sure without seeing the code.

> > > And more importantly, will the error indication be useful enough to
> > > the Lisp program that triggered it?  If we signal an error, we can
> > > make sure of that.
> >
> > We still signal errors if the library returns an error code.
>
> But we need to guess the reason.

I think I've addressed that in the part of the reply you cut out: "we 
also perform additional validation ourselves if something goes wrong". 
That can be extended, if you like.