probable 2.9.0-1 compiler bug (fixed in 2.9.1-RC1) when defining Iterable.iterator with structural Iterator implementations

I don't get this error, but I must be one or two weeks behind trunk.
Anyway, I'm guessing the problem comes from "iterator" being defined
as "iterator()" below, which is a different method. According to the
warning I get, the non-nullary method will override the nullary one.

On Wed, Aug 3, 2011 at 02:34, Chris Twiner wrote:
> Hi All,
>
> Sorry for the fluff title, can't think of a better one, I also can't
> think of how better to search jira (summary ~ "\"Unknown type\""
> brings nothing close, same for description except one for existentials
> and one for dependent types) for this:
>
> class BadIterable extends Iterable[Int] {
>
>  def iterator() =
>    if (System.getProperty("") == "fred")
>      new Iterator[Int]() {
>        def hasNext = false
>        def next() = 1
>      }
>    else
>      new Iterator[Int]() {
>        def hasNext = false
>        def next() = 2
>      }
>
> }
>
> will kill the 2.9.0-1 compiler:
>
> java.lang.Error: Unknown type: Iterator[Int], [class
> scala.tools.nsc.symtab.Types$TypeRef$$anon$6, class scala.t
> ools.nsc.symtab.Types$ErrorType$] TypeRef? true
>        at scala.tools.nsc.symtab.SymbolTable.abort(SymbolTable.scala:35)
>        at scala.tools.nsc.backend.icode.TypeKinds$class.toTypeKind(TypeKinds.scala:390)
>        at scala.tools.nsc.backend.icode.ICodes.toTypeKind(ICodes.scala:25)
>        at scala.tools.nsc.backend.icode.TypeKinds$$anonfun$toTypeKind$1.apply(TypeKinds.scala:387)
>        at scala.tools.nsc.backend.icode.TypeKinds$$anonfun$toTypeKind$1.apply(TypeKinds.scala:387)
>        at scala.collection.TraversableLike$$anonfun$map$1.apply(TraversableLike.scala:194)
> .....
>
> does this ring bells or should I raise a ticket and say its fixed in
> RC1 in case anyone else hits this (or indeed add this example to the
> text of an existing one)?  Naming the Iterator types does work (ie.
> making a class for them) as does a single direct structural type.
>
> Cheers,
> Chris
>

Worth trying but doesn't change the outcome.

On Aug 3, 2011 10:27 PM, "Daniel Sobral" <dcsobral@gmail.com> wrote:
>
> I don't get this error, but I must be one or two weeks behind trunk.
> Anyway, I'm guessing the problem comes from "iterator" being defined
> as "iterator()" below, which is a different method. According to the
> warning I get, the non-nullary method will override the nullary one.
>
> On Wed, Aug 3, 2011 at 02:34, Chris Twiner <chris.twiner@gmail.com> wrote:
> > Hi All,
> >
> > Sorry for the fluff title, can't think of a better one, I also can't
> > think of how better to search jira (summary ~ "\"Unknown type\""
> > brings nothing close, same for description except one for existentials
> > and one for dependent types) for this:
> >
> > class BadIterable extends Iterable[Int] {
> >
> >  def iterator() =
> >    if (System.getProperty("") == "fred")
> >      new Iterator[Int]() {
> >        def hasNext = false
> >        def next() = 1
> >      }
> >    else
> >      new Iterator[Int]() {
> >        def hasNext = false
> >        def next() = 2
> >      }
> >
> > }
> >
> > will kill the 2.9.0-1 compiler:
> >
> > java.lang.Error: Unknown type: Iterator[Int], <error> [class
> > scala.tools.nsc.symtab.Types$TypeRef$$anon$6, class scala.t
> > ools.nsc.symtab.Types$ErrorType$] TypeRef? true
> >        at scala.tools.nsc.symtab.SymbolTable.abort(SymbolTable.scala:35)
> >        at scala.tools.nsc.backend.icode.TypeKinds$class.toTypeKind(TypeKinds.scala:390)
> >        at scala.tools.nsc.backend.icode.ICodes.toTypeKind(ICodes.scala:25)
> >        at scala.tools.nsc.backend.icode.TypeKinds$$anonfun$toTypeKind$1.apply(TypeKinds.scala:387)
> >        at scala.tools.nsc.backend.icode.TypeKinds$$anonfun$toTypeKind$1.apply(TypeKinds.scala:387)
> >        at scala.collection.TraversableLike$$anonfun$map$1.apply(TraversableLike.scala:194)
> > .....
> >
> > does this ring bells or should I raise a ticket and say its fixed in
> > RC1 in case anyone else hits this (or indeed add this example to the
> > text of an existing one)?  Naming the Iterator types does work (ie.
> > making a class for them) as does a single direct structural type.
> >
> > Cheers,
> > Chris
> >
>
>
>
> --
> Daniel C. Sobral
>
> I travel to the future all the time.