Using(new Source(...)) for Scala 2.11

[kwalcock]

In Scala 2.11, Source is not Closeable so that Using(new Source(...)) results in

[error] ...: could not find implicit value for parameter releasable: scala.util.Using.Releasable[scala.io.BufferedSource]
[error]     Using.resource(Source.fromFile(...)) { source =>
[error]                                          ^
[error] one error found

This can be worked around with code like

  implicit object SourceReleaser extends Releasable[Source] {
    override def release(resource: Source): Unit = resource.close
  }

If I add that somewhere, I believe that an additional import will be needed in my code. If it gets added somewhere inside scala.util.Using, which seems to be part of this project, the extra import might not be necessary and that would be very nice to have.

[SethTisue]

sounds like something we'd plausibly merge. want to take a shot at a PR?

[kwalcock]

Some code can be inserted at

scala-collection-compat/compat/src/main/scala-2.11_2.12/scala/util/Using.scala

Lines 395 to 401 in 37d2d5c

	object Releasable {
	/** An implicit `Releasable` for [[java.lang.AutoCloseable `AutoCloseable`s]]. */
	implicit object AutoCloseableIsReleasable extends Releasable[AutoCloseable] {
	def release(resource: AutoCloseable): Unit = resource.close()
	}
	}

so that it looks like that below.

  object Releasable {

    /** An implicit `Releasable` for [[java.lang.AutoCloseable `AutoCloseable`s]]. */
    implicit object AutoCloseableIsReleasable extends Releasable[AutoCloseable] {
      def release(resource: AutoCloseable): Unit = resource.close()
    }

    /** An implicit `Releasable` for [[scala.io.Source `Source`s]] which aren't [[java.lang.AutoCloseable `AutoCloseable`s]] in Scala 2.11. */
    implicit object SourceReleasable extends Releasable[Source] {
      def release(resource: Source): Unit = resource.close()
    }
  }

However, that causes problems for Scala 2.12 because the conversion is then ambiguous. I do not know how to make the Scala 2.11 and 2.12 versions different without duplicating most of the code from the scala-2.11_2.12 directory and putting copies in scala-2.11 and scala-2.12. Other people probably do know how to do this.

My test case was

import scala.io.Source
...
  @Test
  def usingSource(): Unit = {
    Using(Source.fromString("Hello, Source!")) { source =>
      // If this simply compiles, then mission accomplished.
    }
  }

[SethTisue]

I do not know how to make the Scala 2.11 and 2.12 versions different

I could easily be missing something, but we do have src/main/scala-2.11 and src/main/scala-2.12 directories for code that is specific to those versions, alongside the src/main/scala-2.11_2.12 directory for code that is shared by the two. So it isn't clear to me that any other code besides the directly affected code would need to be copy/pasted?

[kwalcock]

See #587. It's more code duplication than I'd like to have, but I know of no better way. Code is copied and pasted between scala-2.11 and scala-2.12.