[bterlson]

I think it's good to note that this proposal is not far along the process. Pattern matching, if it clears TC39 (a tall order, to be honest), won't land in a spec for half a decade at least I would bet.

So, keep the feedback coming, and don't worry that you'll have to learn this syntax tomorrow. It's still very early, and I wouldn't be surprised if there are at least a couple major revisions before anything like this lands in ECMAScript.

[gedy]

With babel plugins/transforms this could be used a lot sooner than that

[bterlson]

Babel has a lot of plugins, and hopefully people don't have to learn all of them. How many people use stage-0 plugins for bind operator or do expressions?

You're right that Babel (and TypeScript!) implement features earlier than they land in the spec, but at least TS does so only when it's almost for sure going to make it in (around stage 3) and people probably shouldn't be using stage 0-2 plugins for anything but experiments, IMO.

[abritinthebay]

> if it clears TC39 (a tall order, to be honest), won't land in a spec for half a decade at least I would bet.

Given current speed of iteration I think you can cut that in half. The key will be implementations - Babel plugins help with that.

[bterlson]

The current speed of iteration means you get updates in smaller batches rather than more throughput. Still important, but it's not like we're letting proposals bake less. Note how so far we've only gotten two big new features post-ES6 - async functions and async generators. Further, some features (e.g. decorators, bind operator) have had babel plugins for years and yet hasn't shipped in a spec.

[abritinthebay]

True. Mostly due to hold ups in the Stage 3 — Stage 4 process I think