streams3

[isaacs]

Crazy idea, maybe, but I think it'd be an improvement, both in functionality and understandability.

Same API as streams2, but remove the confusing modality of flowing/old mode switch.

1. Every time read() is called, and returns some data, a data event fires.
2. resume() will make it call read() repeatedly. Otherwise, no change.
3. pause() will make it stop calling read() repeatedly.
4. pipe(dest) and on('data', fn) will automatically call resume().
5. No switches into old-mode. There's only flowing, and paused. Streams start out paused.

Thoughts? @jclulow @tjfontaine @indutny @bnoordhuis @TooTallNate @Raynos

[Raynos]

Sounds simpler.

Is there still a pulling consumption model ? Can I pull 5 bytes out of a paused stream by calling .read(5)

[jonathanong]

I assumed this is how streams2 worked. No wonder I got confused when trying to use it. I thought "old mode" was the "old api", not an actually different mode.

[isaacs]

@Raynos Yes, as long as the stream is paused at the time.

@jonathanong that's a pretty compelling reason to do this :)

[Raynos]

@isaacs if were making changes can we also have .read(function (err, chunk) {}) ?

[indutny]

Mostly, lgtm. But I'm afraid of nuances and compatibility changes, it feels like there're some cases where we'll ruin old-mode support.

[tellnes]

I would also like to see the proposal from @Raynos (.read(fn)) and .read(n, fn).

[isaacs]

@Raynos @tellnes We're not making changes just for the heck of it. There must be zero API change. read(fn) could be done in a backwards compatible way, but it'd be tricky, easy to do in userland, and I'm not clear on the benefit. Why not do stream.once('data', fn)? If old-mode isn't a permanent switch, you just have to pause() in your function, and it's exactly the same effect.

@indutny Yeah, it's a bit scary. I've already got a start. The only tricky bit is multi-pipe, and I had too many meetings yesterday to finish that. But I've written that several times already in other contexts :) Should have something today or tomorrow.

[glasser]

Should there be a way to detect which mode a stream is in?

[OrangeDog]

No switches into old-mode. There's only flowing, and paused. Streams start out paused.

[glasser]

Er, I mean, to detect if a stream is currently flowing.

[ronkorving]

@isaacs mentioned in nodeup that he had no problem making the private flowing flag public.