diff options
Diffstat (limited to 'src')
-rw-r--r-- | src/dotty/tools/dotc/typer/Applications.scala | 20 |
1 files changed, 12 insertions, 8 deletions
diff --git a/src/dotty/tools/dotc/typer/Applications.scala b/src/dotty/tools/dotc/typer/Applications.scala index 6e78a570d..f7a96c6b4 100644 --- a/src/dotty/tools/dotc/typer/Applications.scala +++ b/src/dotty/tools/dotc/typer/Applications.scala @@ -740,13 +740,19 @@ trait Applications extends Compatibility { self: Typer with Dynamic => def fromScala2x = unapplyFn.symbol.exists && (unapplyFn.symbol.owner is Scala2x) - /** Can `subtp` be made to be a subtype of `tp`, possibly by dropping some - * refinements in `tp`? + /** Is `subtp` a subtype of `tp` or of some generalization of `tp`? + * The generalizations of a type T are the smallest set G such that + * + * - T is in G + * - If a typeref R in G represents a trait, R's superclass is in G. + * - If a type proxy P is not a reference to a class, P's supertype is in G */ def isSubTypeOfParent(subtp: Type, tp: Type)(implicit ctx: Context): Boolean = if (subtp <:< tp) true else tp match { - case tp: RefinedType => isSubTypeOfParent(subtp, tp.parent) + case tp: TypeRef if tp.symbol.isClass => + tp.symbol.is(Trait) && isSubTypeOfParent(subtp, tp.parents.head) + case tp: TypeProxy => isSubTypeOfParent(subtp, tp.superType) case _ => false } @@ -754,13 +760,11 @@ trait Applications extends Compatibility { self: Typer with Dynamic => case mt: MethodType if mt.paramTypes.length == 1 => val unapplyArgType = mt.paramTypes.head unapp.println(i"unapp arg tpe = $unapplyArgType, pt = $selType") - def wpt = widenForMatchSelector(selType) // needed? val ownType = if (selType <:< unapplyArgType) { - //fullyDefinedType(unapplyArgType, "extractor argument", tree.pos) unapp.println(i"case 1 $unapplyArgType ${ctx.typerState.constraint}") selType - } else if (isSubTypeOfParent(unapplyArgType, wpt)(ctx.addMode(Mode.GADTflexible))) { + } else if (isSubTypeOfParent(unapplyArgType, selType)(ctx.addMode(Mode.GADTflexible))) { maximizeType(unapplyArgType) match { case Some(tvar) => def msg = @@ -786,9 +790,9 @@ trait Applications extends Compatibility { self: Typer with Dynamic => unapplyArgType } else { unapp.println("Neither sub nor super") - unapp.println(TypeComparer.explained(implicit ctx => unapplyArgType <:< wpt)) + unapp.println(TypeComparer.explained(implicit ctx => unapplyArgType <:< selType)) errorType( - d"Pattern type $unapplyArgType is neither a subtype nor a supertype of selector type $wpt", + d"Pattern type $unapplyArgType is neither a subtype nor a supertype of selector type $selType", tree.pos) } |