new warnings in 2.10 for enumerations

Russ P.

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May 19, 2013, 11:33:48 PM5/19/13

to scala...@googlegroups.com

I just upgraded from 2.9.2 to 2.10.1, and I am getting warnings that I did not get before. Here's the relevant code:

sealed trait ManeuverType

object ManeuverType { // enumeration of maneuver types

case object alt extends ManeuverType // altitude maneuver

case object vec extends ManeuverType // horizontal "vector" maneuver

case object spd extends ManeuverType // speed manevuer

}

And here are the warnings:

[warn] /home/Maneuver.scala:12: dead code following this

construct

[warn] case object alt extends ManeuverType // altitude maneuver

[warn] ^

[warn] /home/Maneuver.scala:13: dead code following this

construct

[warn] case object vec extends ManeuverType // horizontal "vector" maneuver

[warn] ^

[warn] /home/Maneuver.scala:14: dead code following this

construct

[warn] case object spd extends ManeuverType // speed manevuer

[warn]

What changed in the language or compiler to cause these warnings? Thanks.

--Russ P. ^

Jason Zaugg

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May 19, 2013, 11:54:29 PM5/19/13

to Russ P., scala-user

I'm unable to reproduce. What compiler options are you using.

Here's what I tried:

/code/scala cat sandbox/rp.scala

sealed trait ManeuverType

object ManeuverType { // enumeration of maneuver types

case object alt extends ManeuverType // altitude maneuver

case object vec extends ManeuverType // horizontal "vector" maneuver

case object spd extends ManeuverType // speed manevuer

}

/code/scala RUNNER=scalac scala-hash v2.10.1 -Ydead-code sandbox/rp.scala

[info] v2.10.1 => /Users/jason/usr/scala-v2.10.1-0-g77b864e

/code/scala RUNNER=scalac scala-hash v2.10.0 -Ydead-code sandbox/rp.scala

[info] v2.10.0 => /Users/jason/usr/scala-v2.10.0-0-g18481ce

-jason

Jason Zaugg

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May 20, 2013, 12:09:42 AM5/20/13

to Russ P., scala-user

On Mon, May 20, 2013 at 5:54 AM, Jason Zaugg <jza...@gmail.com> wrote:

On Mon, May 20, 2013 at 5:33 AM, Russ P. <russ.p...@gmail.com> wrote:

I just upgraded from 2.9.2 to 2.10.1, and I am getting warnings that I did not get before. Here's the relevant code:

sealed trait ManeuverType

object ManeuverType { // enumeration of maneuver types

case object alt extends ManeuverType // altitude maneuver
case object vec extends ManeuverType // horizontal "vector" maneuver
case object spd extends ManeuverType // speed manevuer
}

And here are the warnings:

[warn] /home/Maneuver.scala:12: dead code following this
construct
[warn] case object alt extends ManeuverType // altitude maneuver

[warn] ^
[warn] /home/Maneuver.scala:13: dead code following this
construct
[warn] case object vec extends ManeuverType // horizontal "vector" maneuver

[warn] ^
[warn] /home/Maneuver.scala:14: dead code following this
construct
[warn] case object spd extends ManeuverType // speed manevuer
[warn]

What changed in the language or compiler to cause these warnings? Thanks.

This is https://issues.scala-lang.org/browse/SI-6514

It is fixed in the forthcoming release, 2.10.2. We've just had a code freeze for the first release candidate, so it's not far away.