Closed
Description
It appears that dependent types do not correctly propagate through constructors:
trait Foo { type FA }
class Bar(val foo: Foo) {
type FA = foo.FA
}
object Test {
def main(argv: Array[String]) {
val barLong: Bar { type FA = Long } = new Bar(new Foo { type FA = Long })
}
}This always tries to derive the "raw" type for Bar:
[nuttycom@yggdrasil dependent_case_class]$ ~/bin/scala-2.10.0-M2/bin/scalac -Xexperimental Test.scala
Test.scala:8: error: type mismatch;
found : Bar
required: Bar{type FA = Long}
val barLong: Bar { type FA = Long } = new Bar(new Foo { type FA = Long })
Variants don't appear to work either:
[nuttycom@yggdrasil dependent_case_class]$ cat Test.scala
trait Foo { type FA }
class Bar(val foo: Foo) {
type FA = foo.FA
}
object Test {
def main(argv: Array[String]) {
val barLong: Bar { type FA = Long } = new Bar(new Foo { type FA = Long }) {
override type FA = Long
}
}
}
// vim: set ts=4 sw=4 et:
[nuttycom@yggdrasil dependent_case_class]$ ~/bin/scala-2.10.0-M2/bin/scalac -Xexperimental Test.scala
Test.scala:9: error: overriding type FA in class Bar, which equals this.foo.FA;
type FA has incompatible type
override type FA = Long
^
one error found