diff options
Diffstat (limited to 'src/dotty')
-rw-r--r-- | src/dotty/tools/dotc/core/Types.scala | 5 | ||||
-rw-r--r-- | src/dotty/tools/dotc/typer/Applications.scala | 29 |
2 files changed, 28 insertions, 6 deletions
diff --git a/src/dotty/tools/dotc/core/Types.scala b/src/dotty/tools/dotc/core/Types.scala index 559839db2..db518d959 100644 --- a/src/dotty/tools/dotc/core/Types.scala +++ b/src/dotty/tools/dotc/core/Types.scala @@ -2266,6 +2266,11 @@ object Types { protected def computeSignature(implicit ctx: Context) = resultSignature + def isPolymorphicMethodType: Boolean = resType match { + case _: MethodType => true + case _ => false + } + def instantiate(argTypes: List[Type])(implicit ctx: Context): Type = resultType.substParams(this, argTypes) diff --git a/src/dotty/tools/dotc/typer/Applications.scala b/src/dotty/tools/dotc/typer/Applications.scala index 64047cc1e..c57dd7aab 100644 --- a/src/dotty/tools/dotc/typer/Applications.scala +++ b/src/dotty/tools/dotc/typer/Applications.scala @@ -848,11 +848,19 @@ trait Applications extends Compatibility { self: Typer => else (sym1 is Module) && isDerived(sym1.companionClass, sym2) /** Is alternative `alt1` with type `tp1` as specific as alternative - * `alt2` with type `tp2` ? This is the case if + * `alt2` with type `tp2` ? * - * 1. `tp2` is a method or poly type but `tp1` isn't, or `tp1` is nullary. - * 2. `tp2` and `tp1` are method or poly types and `tp2` can be applied to the parameters of `tp1`. - * 3. Neither `tp1` nor `tp2` are method or poly types and `tp1` is compatible with `tp2`. + * 1. A method `alt1` of type (p1: T1, ..., pn: Tn)U is as specific as `alt2` + * if `alt2` is applicable to arguments (p1, ..., pn) of types T1,...,Tn + * or if `alt1` is nullary. + * 2. A polymorphic member of type [a1 >: L1 <: U1, ..., an >: Ln <: Un]T is as + * specific as `alt2` of type `tp2` if T is as specific as `tp2` under the + * assumption that for i = 1,...,n each ai is an abstract type name bounded + * from below by Li and from above by Ui. + * 3. A member of any other type `tp1` is: + * a. always as specific as a method or a polymorphic method. + * b. as specific as a member of any other type `tp2` if `tp1` is compatible + * with `tp2`. */ def isAsSpecific(alt1: TermRef, tp1: Type, alt2: TermRef, tp2: Type): Boolean = ctx.traceIndented(i"isAsSpecific $tp1 $tp2", overload) { tp1 match { case tp1: PolyType => @@ -870,8 +878,17 @@ trait Applications extends Compatibility { self: Typer => tp1.paramTypes.isEmpty && tp2.isInstanceOf[MethodOrPoly] case _ => tp2 match { - case tp2: MethodOrPoly => true - case _ => isCompatible(tp1, tp2) + case tp2: MethodType => true + case tp2: PolyType if tp2.isPolymorphicMethodType => true + case tp2: PolyType => + val nestedCtx = ctx.fresh.setExploreTyperState + + { + implicit val ctx: Context = nestedCtx + isCompatible(tp1, constrained(tp2).resultType) + } + case _ => + isCompatible(tp1, tp2) } }} |