[KenoFischer]

Yes, I think preliminary tests showed that it was faster than Grisu (which is what we're using in Base currently). It also seems significantly simpler (Grisu is generally fairly simple but has a custom BigInt implementation to handle some corner cases, which makes things complicated). Not a good time right now to swap the float print algorithm, but a good project for post-1.0.

I don't see an issue about it at the moment. I guess we just expect Jacob to PR it at some point. IIRC he also wrote the Grisu implementation that's in Base.

[qop]

To hijack this thread a different direction for a moment, is this type of change one that would be allowed to occur in 1.x? How is it determined what changes are suitable for 1.x and what will wait for 2.0, once 1.0 is released?

I'm very interested in how detailed and coordinated the Julia team has become regarding the longer term future of Julia. Admirable effort all around.

[KenoFischer]

I'd say probably yes. Changes are suitable for 1.x if they are not generally breaking for user code. This change probably wouldn't be considered breaking, but we'd have to look at it at the time.

[ulfjack]

FYI: Grisu2 and Ryu should produce bit-identical outputs in all cases.