From bbdd570ccc465d11fbabd2251df8f98cb7078b81 Mon Sep 17 00:00:00 2001 From: Paul Phillips Date: Thu, 3 May 2012 19:40:53 -0700 Subject: [PATCH] Clarified the status of SI-13. Through the oracle of pos/t1279a.scala. --- test/files/pos/t1279a.scala | 61 ++++++++++++++++++------------------- 1 file changed, 30 insertions(+), 31 deletions(-) diff --git a/test/files/pos/t1279a.scala b/test/files/pos/t1279a.scala index 9212b583d492..18b1e53f463e 100644 --- a/test/files/pos/t1279a.scala +++ b/test/files/pos/t1279a.scala @@ -1,40 +1,39 @@ -// see #13 -// providing the type parameter in the recursive call to all4Impl -// avoids the problem - - // covariant linked list -abstract class M -{ self => - - type T - final type selfType = M {type T <: self.T} - type actualSelfType >: self.type <: selfType - - def next: selfType +abstract class M { + self => + type T + final type selfType = M {type T <: self.T} + type actualSelfType >: self.type <: selfType - // I don't understand why this doesn't compile, but that's a separate matter - // error: method all2 cannot be accessed in M.this.selfType - // because its instance type => Stream[M{type T <: M.this.selfType#T}] - // contains a malformed type: M.this.selfType#T - // def all2: Stream[M {type T <: self.T}] = Stream.cons(self: actualSelfType, next.all2) + def next: selfType + // I don't understand why this doesn't compile, but that's a separate matter + // error: method all2 cannot be accessed in M.this.selfType + // because its instance type => Stream[M{type T <: M.this.selfType#T}] + // contains a malformed type: M.this.selfType#T + def all2: Stream[M {type T <: self.T}] = Stream.cons(self: actualSelfType, next.all2) - // compiles successfully - // def all3: Stream[M {type T <: self.T}] = all3Impl(self: actualSelfType) - // private def all3Impl(first: M {type T <: self.T}): Stream[M {type T <: self.T}] = Stream.cons(first, all3Impl(first.next)) + // compiles successfully + def all3: Stream[M {type T <: self.T}] = all3Impl(self: actualSelfType) + private def all3Impl(first: M {type T <: self.T}): Stream[M {type T <: self.T}] = Stream.cons(first, all3Impl(first.next)) - - - def all4: Stream[M {type T <: self.T}] = Unrelated.all4Impl[T](self: actualSelfType) + def all4: Stream[M {type T <: self.T}] = Unrelated.all4Impl[T](self: actualSelfType) } -object Unrelated -{ - // TODO!!! fix this bug for real, it compiles successfully, but weird types are inferred - // def all4Impl[U](first: M {type T <: U}): Stream[M {type T <: U}] = Stream.cons(first, all4Impl(first.next)) - -// compiles successfully - def all4Impl[U](first: M {type T <: U}): Stream[M {type T <: U}] = Stream.cons(first, all4Impl[U](first.next)) +// TODO!!! fix this bug for real, it compiles successfully, but weird types are inferred +object Unrelated { + // compiles successfully + def all4Impl[U](first: M {type T <: U}): Stream[M {type T <: U}] = Stream.cons(first, all4Impl[U](first.next)) + + // should compile successfully without the [U], but: + // def all4ImplFail[U](first: M {type T <: U}): Stream[M {type T <: U}] = Stream.cons(first, all4ImplFail(first.next)) + // + // test/files/pos/t1279a.scala:31: error: type mismatch; + // found : first.selfType + // (which expands to) M{type T <: first.T} + // required: M{type T <: Nothing} + // def all4ImplFail[U](first: M {type T <: U}): Stream[M {type T <: U}] = Stream.cons(first, all4ImplFail(first.next)) + // ^ + // one error found }