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author | Adriaan Moors <adriaan.moors@epfl.ch> | 2010-05-04 13:53:09 +0000 |
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committer | Adriaan Moors <adriaan.moors@epfl.ch> | 2010-05-04 13:53:09 +0000 |
commit | 7abeacab53286233d4b150e713ca253c08f38bfd (patch) | |
tree | e6f75af92ef5602d9170ba1ad91df20b20111b4c /test/files/pos/t3177.scala | |
parent | 6bc86b824867b9c0eaab79bcd798d05759a9167a (diff) | |
download | scala-7abeacab53286233d4b150e713ca253c08f38bfd.tar.gz scala-7abeacab53286233d4b150e713ca253c08f38bfd.tar.bz2 scala-7abeacab53286233d4b150e713ca253c08f38bfd.zip |
closes #3373, #3177: validity check of an impli...
closes #3373, #3177: validity check of an implicit value should consider
the value as well as its accessor review by odersky
Diffstat (limited to 'test/files/pos/t3177.scala')
-rw-r--r-- | test/files/pos/t3177.scala | 39 |
1 files changed, 39 insertions, 0 deletions
diff --git a/test/files/pos/t3177.scala b/test/files/pos/t3177.scala new file mode 100644 index 0000000000..9f9528faec --- /dev/null +++ b/test/files/pos/t3177.scala @@ -0,0 +1,39 @@ +trait InvariantFunctor[F[_]] { + def xmap[A, B](ma: F[A], f: A => B, g: B => A): F[B] +} + +object InvariantFunctor { + import Endo._ + + implicit val EndoInvariantFunctor = new InvariantFunctor[Endo] { + def xmap[A, B](ma: Endo[A], f: A => B, g: B => A): Endo[B] = (b: B) => f(ma(g(b))) + } + + // The definition about fails with: + // anon-type.scala:9: error: not found: value b + // def xmap[A, B](ma: Endo[A], f: A => B, g: B => A): Endo[B] = (b: B) => f(ma(g(b))) + // ^ + // anon-type.scala:8: error: not found: type $anon + // implicit val EndoInvariantFunctor = new InvariantFunctor[Endo] { + // ^ + + + // These both work: + // implicit val EndoInvariantFunctorAscribed: InvariantFunctor[Endo] = new InvariantFunctor[Endo] { + // def xmap[A, B](ma: Endo[A], f: A => B, g: B => A): Endo[B] = (b: B) => f(ma(g(b))) + // } + // + // implicit val EndoInvariantFunctorStubbed = new InvariantFunctor[Endo] { + // def xmap[A, B](ma: Endo[A], f: A => B, g: B => A): Endo[B] = error("stub") + // } +} + +trait Endo[X] + +object Endo { + implicit def EndoTo[A](f: A => A): Endo[A] = new Endo[A] { + def apply(a: A) = f(a) + } + + implicit def EndoFrom[A](e: Endo[A]): A => A = e.apply(_) +}
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