diff options
Diffstat (limited to 'src/compiler/scala/tools/nsc/typechecker/RefChecks.scala')
| -rw-r--r-- | src/compiler/scala/tools/nsc/typechecker/RefChecks.scala | 14 |
1 files changed, 12 insertions, 2 deletions
diff --git a/src/compiler/scala/tools/nsc/typechecker/RefChecks.scala b/src/compiler/scala/tools/nsc/typechecker/RefChecks.scala index f60ffae9b5..f6552d9fc5 100644 --- a/src/compiler/scala/tools/nsc/typechecker/RefChecks.scala +++ b/src/compiler/scala/tools/nsc/typechecker/RefChecks.scala @@ -96,7 +96,10 @@ abstract class RefChecks extends InfoTransform { * 1.7. If O is an abstract type then * either M is an abstract type, and M's bounds are sharper than O's bounds. * or M is an unparameterized type alias or class which conforms to O's bounds. - * 1.8. If O and M are values, then M's type is a subtype of O's type. + * 1.8. If O and M are values, then + * 1.8.1 M's type is a subtype of O's type, or + * 1.8.2 M is of type []S, O is of type ()T and S <: T, or + * 1.8.3 M is of type ()S, O is of type []T and S <: T, or * 2. Check that only abstract classes have deferred members * 3. Check that every member with an `override' modifier * overrides some other member. @@ -115,6 +118,12 @@ abstract class RefChecks extends InfoTransform { else ""))) ); + def overridesType(tp1: Type, tp2: Type): boolean = Pair(tp1, tp2) match { + case Pair(MethodType(List(), rtp1), PolyType(List(), rtp2)) => rtp1 <:< rtp2 + case Pair(PolyType(List(), rtp1), MethodType(List(), rtp2)) => rtp1 <:< rtp2 + case _ => tp1 <:< tp2 + } + /* Check that all conditions for overriding `other' by `member' are met. */ def checkOverride(clazz: Symbol, member: Symbol, other: Symbol): unit = { val pos = if (member.owner == clazz) member.pos else clazz.pos; @@ -179,8 +188,9 @@ abstract class RefChecks extends InfoTransform { if (!(self.memberInfo(other).bounds containsType self.memberType(member))) // (1.7) overrideTypeError(); } else if (other.isTerm) { - if (!(self.memberInfo(member) <:< (self.memberInfo(other)))) // 8 + if (!overridesType(self.memberInfo(member), self.memberInfo(other))) { // 8 overrideTypeError(); + } } } } |