Handling higher-kinded types with lambdas

Switch to the new scheme where higher-kinded types (and also some polymorphic
type aliases) are represented as instances of Lambda traits.

1 files changed, 35 insertions, 0 deletions

diff --git a/tests/pos/t2994.scala b/tests/pos/t2994.scala
new file mode 100644
index 000000000..c7421c42a
--- /dev/null
+++ b/tests/pos/t2994.scala
@@ -0,0 +1,35 @@
+object Naturals {
+  trait NAT {
+    type a[s[_ <: NAT] <: NAT, z <: NAT] <: NAT
+    type v = a[SUCC, ZERO]
+  }
+  final class ZERO extends NAT {
+    type a[s[_ <: NAT] <: NAT, z <: NAT] = z
+  }
+  final class SUCC[n <: NAT] extends NAT {
+    type a[s[_ <: NAT] <: NAT, z <: NAT] = s[n#a[s, z]]
+  }
+  type _0 = ZERO
+  type _1 = SUCC[_0]
+  type _2 = SUCC[_1]
+  type _3 = SUCC[_2]
+  type _4 = SUCC[_3]
+  type _5 = SUCC[_4]
+  type _6 = SUCC[_5]
+
+
+  // crashes scala-2.8.0 beta1
+  trait MUL[n <: NAT, m <: NAT] extends NAT {
+    trait curry[n[_, _], s[_]] { type f[z <: NAT] = n[s, z] }
+    type a[s[_ <: NAT] <: NAT, z <: NAT] = n#a[curry[m#a, s]#f, z]
+  }
+
+}
+
+object Test {
+  trait Bar[X[_]]
+  trait Baz[S[_] <: Bar[S]] {
+    type Apply[T]
+  }
+  trait Foo[V[_] <: Bar[V]] extends Bar[Baz[V]#Apply]
+}