ENSIME: The Next Generation

jilen · January 27, 2022, 11:08am

Does it works with Java 17 ?
Tried but ended up with hangs while doing completion.

fommil · January 27, 2022, 10:27pm

that’s probably not a relevant factor in whatever you’re experiencing, I’ve for sure used it in a Java 17 project. It’ll almost certainly break on Java 8 because I forget to test on it these days.

jilen · January 29, 2022, 8:48am

Any suggestion ?

fommil · January 31, 2022, 4:00pm

It’s impossible to say anything without seeing your project. Is it public? Does Metals / IntelliJ work on that completion? Any error messages?

To debug further I’d suggest sticking some println into the ensime code and rebuild the .jar file. Try to reproduce it in the tests folder so that it can be automated.

jilen · February 7, 2022, 10:43am

Figure it out that the graalvm does not working with the ZGC, so the server never started.

fommil · February 7, 2022, 11:10am

oh interesting. So that’s here in launcher.scala

    val javaFlags = if (javaVersion >= 13) {
      List("-XX:+UseZGC")
    } else if (javaVersion >= 9) {
      List("-XX:+ShrinkHeapInSteps")
    } else Nil

The reason for this code is because ZGC will reduce the physical memory in line with the heap usage and I wanted to keep the overhead of the ensime server as small as possible.

Do you have a suggestion of how to detect graalvm and/or a more appropriate flag? As a potential workaround I could only enable ZGC on openjdk. Richard Stallman would like that: make it better for users of Free Software and a worse experience for those using proprietary systems

jilen · February 7, 2022, 11:17am

java -version shall contain string GraalVM. But no such system properties indicates it is GraalVM.
Maybe just add something to README is enough.

jilen · February 7, 2022, 11:29am

Suggestion: register to standard completion-at-point-functions instead of company-backends, then, it could get ride of the company dependency.

sideeffffect · February 7, 2022, 2:36pm

The reason for this code is because ZGC will reduce the physical memory in line with the heap usage

AFAIK G1 does that now too, so one doesn’t need to change the default GC (G1) to achieve this end

Good luck with ENSIME!

fommil · February 7, 2022, 5:33pm

now being the important part. I still have Java 13 and 15 projects. I should probably have a 17+ check that does nothing.

fommil · February 7, 2022, 5:34pm

I use company-mode so I’m not sure what advantage that would give me. Would I lose or gain any functionality?

sideeffffect · February 7, 2022, 5:35pm

Any version between 11 and 17 is officially dead by now, so I was guessing you might want to easy the burden of supporting those versions…
But life is complicated, you know what you need best

fommil · February 7, 2022, 7:45pm

People keep telling me “this thing” or “that thing” is dead, and yet I’m happily using it just fine. I think some people attach a different meaning to these words than I do. I hope I’m not just walking around with expired parrots in my pocket.

jilen · February 8, 2022, 1:56am

Not very much to gain indeed, but most modes like ‘emacs-lisp-mode’ or css-mode define completion function to the builtin completion-at-point-function. The only advantage I can see is user can use other completion ui like https://github.com/minad/corfu . And company actually support completion-at-point-functions via company-capf

wsdjeg · April 24, 2022, 2:20pm

Hi @fommil I want to use ensime in spacevim, and create a vim plugin for it. How to visite this repo, thanks.

fommil · May 3, 2022, 9:48am

Hi @wsdjeg that’d be really interesting. You don’t need access to the repo to do that, just download the source code from ensime.github.io and take it from there! Happy hacking.

fommil · October 7, 2022, 10:52am

https://ensime.github.io/ v3.0.2 “The Naked Now” has intial LSP support for vscode, thanks for all the help folk.

robmwalsh · October 18, 2022, 1:07am

Would you be interested in a vscode extension to consume the new LSP support?

edit: nevermind, I see there’s one in the new repo Giving it a go now.

fommil · October 20, 2022, 10:52am

v3.0.5 now available with a feature complete beta vscode extension (now available as an easy download) at https://ensime.github.io/

fommil · October 21, 2022, 2:35pm

@smarter ENSIME isn’t providing diagnostic information, but if it ever does I’d rather get it from the batch compiler (not the interactive compiler) in both Scala 2 and Scala 3.

The only way I can do this is by registering, from a compiler plugin, to the Reporter. Is that possible in Scala 3? In Scala 2 it is theoretically possible to just mutate the Reporter in Global, which won’t work if something has cached the reference, but should work in theory.

Having a way to have plugins register on startup to messages sent to the Reporter seems like it might be a good feature in general.