Syntax checking and ECMA2026

[agoujot]

(Seen at Wikipedia, replicated at https://ace.c9.io/.)

The syntax checking feature reports ECMA2026 features (here private identifiers) as errors.

I presume this is intentional, as, you know, it's 2025 not 2026. But (according to MDN) all major browsers support that, so in effect it's not an error.

So I was wondering:

• What does ace use for syntax checking?
• What's the timeline used for adding ECMA features?

Thanks.