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Flippin' Scala

Posted on August 22, 2008, in Programming

Once upon a time, I tried to write some Scala 2.7.1 for Functional Java and Reductio, but the compiler broke. So I filed the bug and waited for a fix. Thanks to Odersky et. al., the fix came promptly, so I started using one of the Scala 2.7.1->2.7.2 nightly builds and then I could compile my Scala code, yay! But that didn’t stop users complaining about crashes when using Scala 2.7.1 due its bad class file parser. Some users even stopped using Reductio because they don’t trust non-release builds. Oh well.

So I try out this new code snippet, nothing complicated:

class Foo[F[_]]

object Foo {
  def foo(n: Int)(implicit f: Foo[IN] forSome { type IN[_] }) = "foo"

  implicit val z: Foo[List] = new Foo[List]

  val t = foo(7)
}

But Scala 2.7.1 falls over. So does the 2.7.1->2.7.2 nightly build that I was using. Ugh! So I try out Scala 2.7.2-RC1, yay it compiles my legitimate source file. But does it compile all my other source?

Er no, Scala 2.7.2-RC1 produces bad class files when compiling code that is otherwise fine with previous Scala versions. In an attempt to obtain one bug fix I have also had to adopt another – one that makes its use non-viable. I am stuck with dealing with the former bug, which is also somewhat non-viable but only slightly more so than the latter. Give me a friggin’ break!

Ugh, this is not the first occurrence of this silliness. Flippin’ Scala, does this shit ever stop?