scalac: bad option '-Xelide-below' was ignored

[sabenuse]

3.1.2

the Compile opton -Xelide-below have removed？

[Florian3k]

It's not present in Scala 3:
https://docs.scala-lang.org/scala3/guides/migration/options-lookup.html

[szymon-rd]

In general, you should be able to achieve similar behavior with inline. What do you want to do?

[sabenuse]

how can i add it ？

[szymon-rd]

@sabenuse It is a new language feature in Scala 3. If you use the inline if, then you can introduce a behavior that makes a method de facto elided at compile-time:

type LogLevel = Int

object LogLevel {
  inline val Info = 0
  inline val Warn = 1
  inline val Debug = 2
}

inline val appLogLevel = LogLevel.Warn

inline def log(msg: String, inline level: LogLevel): Unit = 
  inline if (level <= appLogLevel) then println(msg)

log("Warn log", LogLevel.Warn)

log("Debug log", LogLevel. Debug)

[b-studios]

Hey, does anybody know whether it is supposed to be supported in the future? I am surprised to find it in the docs:

https://dotty.epfl.ch/api/scala/annotation/elidable.html

but get the same message as the OP.

Use-case I want to use it for "design by contract". Disabling assertions for production in a compiler flag seems like a reasonable thing to do. Having to develop your own assertions might not scale to code that already uses assertions.

[tpunder]

I just ran into this issue while trying to cross-compile Scala 2 and Scala 3 code. I assumed it was supported since @elidable is still part of the API (https://scala-lang.org/api/3.2.2/scala/annotation/elidable.html) and the code compiles fine using @elidable.

If it is no longer supported then it would probably be nice to remove it from the API or at least add a big note in the API docs that it is not supported in Scala 3 and that -Xelide-below is no longer valid.

[SethTisue]

at least add a big note in the API docs that it is not supported in Scala 3

yes, a PR with that would be welcome over at https://github.com/scala/scala

[liontiger23]

Is the removal of compiler option intentional?
Or can someone in theory support this option via PR?