Hacker News Reader

Comment by bodski | Hacker News Reader

scala interpreter/REPL is starting up in about 0.5 seconds now compared to 7-8 seconds with 2.9.0.1 on my system using Sun JDK 64-bit.

System scripting in Scala suddenly got a lot more appealing :-)

View on HN

Hang on--that's 0.5s for server (64-bit) hotspot? That's astonishing.

Any details on how they were able to achieve it?

Aye, 64-bit hotspot with implicit -server switch, but going on your astonishment I took a look and it seems the 0.5s time is only achieved with fsc running from previous runs of the REPL. So from cold, i.e. no fsc running it takes about 3 seconds. 2.9.0-1 was taking 7-8 seconds to get the REPL prompt regardless of whether fsc was running already, so this is still like night and day for me :-)

Amongst other things it looks like Paul Phillips (a.k.a extempore) has done a lot of optimisation work. This looks like a pretty important one:

https://codereview.scala-lang.org/fisheye/changelog/scala-sv...

Oh, ok, so fsc is comparable to just connecting to a nailgun daemon, right?

I don't actually know Scala; is there a tl;dr for that link?

(I couldn't find a good summation, maybe there are more substantive m-list threads in internals:

http://groups.google.com/group/scala-internals/browse_frm/th...

http://groups.google.com/group/scala-internals/browse_thread...

That's still a pretty massively long time compared to, say, Ocaml or Haskell. (0.01 seconds for hello world, for both of them)

It's still appeals too long for me.

Reply on news.ycombinator.com