diff options
Diffstat (limited to 'src/dotty/tools/dotc/core/TypeComparer.scala')
-rw-r--r-- | src/dotty/tools/dotc/core/TypeComparer.scala | 33 |
1 files changed, 17 insertions, 16 deletions
diff --git a/src/dotty/tools/dotc/core/TypeComparer.scala b/src/dotty/tools/dotc/core/TypeComparer.scala index 64faa6d93..1f80a8a10 100644 --- a/src/dotty/tools/dotc/core/TypeComparer.scala +++ b/src/dotty/tools/dotc/core/TypeComparer.scala @@ -16,7 +16,7 @@ import scala.util.control.NonFatal /** Provides methods to compare types. */ -class TypeComparer(initctx: Context) extends DotClass with ConstraintHandling with Skolemization { +class TypeComparer(initctx: Context) extends DotClass with ConstraintHandling { implicit val ctx: Context = initctx val state = ctx.typerState @@ -531,19 +531,16 @@ class TypeComparer(initctx: Context) extends DotClass with ConstraintHandling wi * rebase both itself and the member info of `tp` on a freshly created skolem type. */ protected def hasMatchingMember(name: Name, tp1: Type, tp2: RefinedType): Boolean = { - val saved = skolemsState - if (skolemsState == Skolemization.SkolemsDisallowed) skolemsState = Skolemization.SkolemsAllowed - try { - val rebindNeeded = tp2.refinementRefersToThis - val base = if (rebindNeeded) ensureStableSingleton(tp1) else tp1 - val rinfo2 = if (rebindNeeded) tp2.refinedInfo.substRefinedThis(tp2, base) else tp2.refinedInfo - def qualifies(m: SingleDenotation) = isSubType(m.info, rinfo2) - def memberMatches(mbr: Denotation): Boolean = mbr match { // inlined hasAltWith for performance - case mbr: SingleDenotation => qualifies(mbr) - case _ => mbr hasAltWith qualifies - } - /*>|>*/ ctx.traceIndented(i"hasMatchingMember($base . $name :? ${tp2.refinedInfo}) ${base.member(name).info.show} $rinfo2", subtyping) /*<|<*/ { - memberMatches(base member name) || + val rebindNeeded = tp2.refinementRefersToThis + val base = if (rebindNeeded) ensureStableSingleton(tp1) else tp1 + val rinfo2 = if (rebindNeeded) tp2.refinedInfo.substRefinedThis(tp2, base) else tp2.refinedInfo + def qualifies(m: SingleDenotation) = isSubType(m.info, rinfo2) + def memberMatches(mbr: Denotation): Boolean = mbr match { // inlined hasAltWith for performance + case mbr: SingleDenotation => qualifies(mbr) + case _ => mbr hasAltWith qualifies + } + /*>|>*/ ctx.traceIndented(i"hasMatchingMember($base . $name :? ${tp2.refinedInfo}) ${base.member(name).info.show} $rinfo2", subtyping) /*<|<*/ { + memberMatches(base member name) || tp1.isInstanceOf[SingletonType] && { // special case for situations like: // class C { type T } @@ -554,9 +551,13 @@ class TypeComparer(initctx: Context) extends DotClass with ConstraintHandling wi case _ => false } } - } } - finally skolemsState = saved + } + + final def ensureStableSingleton(tp: Type): SingletonType = tp.stripTypeVar match { + case tp: SingletonType if tp.isStable => tp + case tp: ValueType => SkolemType(tp) + case tp: TypeProxy => ensureStableSingleton(tp.underlying) } /** Skip refinements in `tp2` which match corresponding refinements in `tp1`. |