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For what it's worth, this isn't just an evolution of the language, but a complete rewrite of the compiler. I appreciate that they're taking the time to do it ri

For what it's worth, this isn't just an evolution of the language, but a complete rewrite of the compiler. I appreciate that they're taking the time to do it right. They probably could've pushed new, non-trivial features out faster if they weren't doing a total rewrite.

BurningFrog 8y ago
This does nothing to change my opinion that total rewrites are almost always a horrible idea.
- pas 8y ago
  The Scala compiler has to be cleaned up. Maybe rewritten, maybe not. Dotty started as a fork of Scala, and now Odersky decided/announced that it'll be merged back eventually. (And it should conform to whatever the Scala language is/will be after the SIP processes for 3.0.)
- JoeAltmaier 8y ago
  The old saying: "Its bigger and slower, but at least its more expensive!" My experience says, a rewrite just has different bugs. Combined with delay and cost, its often not worthwhile.
- ionforce 8y ago
  I've never seen a system or project that's had a "big" change that wasn't always a total rewrite. I guess it's always envisioned differently like "can we tackle this subsystem in isolation".
Blaisorblade0 8y ago
Scalac has evolved considerably, but it appears to be much harder to evolve. The Scalac team and contributors are backporting some of the Dotty features, but this is far from a trivial effort. Doing the same changes in Dotty is typically much easier in comparison.
hota_mazi 8y ago
Pity that in this rewrite, they were unable to speed up compilation speed. From the latest reports, dotty appears to compile at about the same speed (if not more slowly than) scalac.
- acjohnson55 8y ago
  This is pure speculation on my part, but my guess would be that better, simpler foundations and a fresh start end up unlocking a lot of optimization opportunities in the long run. But it would seem foolish to invest too much in optimization while things are still in flux.
- spockz 8y ago
  Where did you get that from? I’ve seen performance increases of 2-3x mentioned on conference talks: eg here https://d-d.me/talks/scalaworld2015/ https://d-d.me/talks/scalaworld2015/ slide 50.

BurningFrog 8y ago

This does nothing to change my opinion that total rewrites are almost always a horrible idea.

pas 8y ago
The Scala compiler has to be cleaned up. Maybe rewritten, maybe not. Dotty started as a fork of Scala, and now Odersky decided/announced that it'll be merged back eventually. (And it should conform to whatever the Scala language is/will be after the SIP processes for 3.0.)
JoeAltmaier 8y ago
The old saying: "Its bigger and slower, but at least its more expensive!" My experience says, a rewrite just has different bugs. Combined with delay and cost, its often not worthwhile.
ionforce 8y ago
I've never seen a system or project that's had a "big" change that wasn't always a total rewrite. I guess it's always envisioned differently like "can we tackle this subsystem in isolation".

Blaisorblade0 8y ago

Scalac has evolved considerably, but it appears to be much harder to evolve. The Scalac team and contributors are backporting some of the Dotty features, but this is far from a trivial effort. Doing the same changes in Dotty is typically much easier in comparison.

hota_mazi 8y ago

Pity that in this rewrite, they were unable to speed up compilation speed. From the latest reports, dotty appears to compile at about the same speed (if not more slowly than) scalac.

acjohnson55 8y ago
This is pure speculation on my part, but my guess would be that better, simpler foundations and a fresh start end up unlocking a lot of optimization opportunities in the long run. But it would seem foolish to invest too much in optimization while things are still in flux.
spockz 8y ago
Where did you get that from? I’ve seen performance increases of 2-3x mentioned on conference talks: eg here https://d-d.me/talks/scalaworld2015/ https://d-d.me/talks/scalaworld2015/ slide 50.