Bug with case classes in filter

[andrewdbate]

Suppose we have the case class:

case class MyExample(x: Int)

We could use it to pattern match as follows:

def example {
  val ex: Array[MyExample] = new Array[MyExample](10)
  optimize {
    for (MyExample(x) <- ex) {
      println(x)
    }
  }
}

The following syntactic modification of the above code also works without problem:

def example: Unit = { // This is the only line that has changed
  val ex: Array[MyExample] = new Array[MyExample](10)
  optimize {
    for (MyExample(x) <- ex) {
      println(x)
    }
  }
}

However, the following syntactic modification causes the compiler to crash big time!

def example = { // Again, this is the only line that has changed
  val ex: Array[MyExample] = new Array[MyExample](10)
  optimize {
    for (MyExample(x) <- ex) {
      println(x)
    }
  }
}

When I try to compile a class that contains the last method above, it bombs out with the following internal exception and stack trace:

scala.reflect.internal.Symbols$CyclicReference: illegal cyclic reference involving method example
    at scala.reflect.internal.Symbols$Symbol$$anonfun$info$3.apply(Symbols.scala:1418)
    at scala.reflect.internal.Symbols$Symbol$$anonfun$info$3.apply(Symbols.scala:1416)
    at scala.Function0$class.apply$mcV$sp(Function0.scala:40)
    at scala.runtime.AbstractFunction0.apply$mcV$sp(AbstractFunction0.scala:12)
    at scala.reflect.internal.Symbols$Symbol.lock(Symbols.scala:532)
    at scala.reflect.internal.Symbols$Symbol.info(Symbols.scala:1416)
    at scala.reflect.internal.Symbols$Symbol.info(Symbols.scala:174)
    at scalaxy.streams.HacksAndWorkarounds$$anon$1$$anonfun$traverse$2.apply(HacksAndWorkarounds.scala:31)
    at scalaxy.streams.HacksAndWorkarounds$$anon$1$$anonfun$traverse$2.apply(HacksAndWorkarounds.scala:26)
    at scala.Option$WithFilter.foreach(Option.scala:208)
    at scalaxy.streams.HacksAndWorkarounds$$anon$1.traverse(HacksAndWorkarounds.scala:26)
    at scala.reflect.api.Trees$Traverser.traverseTrees(Trees.scala:2484)
    at scala.reflect.internal.Trees$class.traverseComponents$1(Trees.scala:1277)
    at scala.reflect.internal.Trees$class.itraverse(Trees.scala:1323)
    at scala.reflect.internal.SymbolTable.itraverse(SymbolTable.scala:16)
    at scala.reflect.internal.SymbolTable.itraverse(SymbolTable.scala:16)
    at scala.reflect.api.Trees$Traverser.traverse(Trees.scala:2475)
    at scalaxy.streams.HacksAndWorkarounds$$anon$1.traverse(HacksAndWorkarounds.scala:43)
    at scala.reflect.api.Trees$Traverser.traversePattern(Trees.scala:2476)
    at scala.reflect.internal.Trees$class.traverseComponents$1(Trees.scala:1230)
    at scala.reflect.internal.Trees$class.itraverse(Trees.scala:1323)
    at scala.reflect.internal.SymbolTable.itraverse(SymbolTable.scala:16)
    at scala.reflect.internal.SymbolTable.itraverse(SymbolTable.scala:16)
    at scala.reflect.api.Trees$Traverser.traverse(Trees.scala:2475)
    at scalaxy.streams.HacksAndWorkarounds$$anon$1.traverse(HacksAndWorkarounds.scala:43)
    at scala.reflect.api.Trees$Traverser.traverseTrees(Trees.scala:2484)
    at scala.reflect.api.Trees$Traverser.traverseCases(Trees.scala:2487)
    at scala.reflect.internal.Trees$class.traverseComponents$1(Trees.scala:1258)
    at scala.reflect.internal.Trees$class.itraverse(Trees.scala:1323)
    at scala.reflect.internal.SymbolTable.itraverse(SymbolTable.scala:16)
    at scala.reflect.internal.SymbolTable.itraverse(SymbolTable.scala:16)
    at scala.reflect.api.Trees$Traverser.traverse(Trees.scala:2475)
    at scalaxy.streams.HacksAndWorkarounds$$anon$1.traverse(HacksAndWorkarounds.scala:43)
    ...

Lastly, on a general note, many thanks for all that you have been doing with Scalaxy/Streams recently. It has been of tremendous value in my current project!