diff options
| -rw-r--r-- | src/dotty/tools/dotc/config/Printers.scala | 1 | ||||
| -rw-r--r-- | src/dotty/tools/dotc/core/TypeApplications.scala | 23 | ||||
| -rw-r--r-- | src/dotty/tools/dotc/core/TypeComparer.scala | 6 | ||||
| -rw-r--r-- | src/dotty/tools/dotc/typer/VarianceChecker.scala | 3 |
4 files changed, 19 insertions, 14 deletions
diff --git a/src/dotty/tools/dotc/config/Printers.scala b/src/dotty/tools/dotc/config/Printers.scala index 5bfe1d0b6..0cbfb6880 100644 --- a/src/dotty/tools/dotc/config/Printers.scala +++ b/src/dotty/tools/dotc/config/Printers.scala @@ -23,6 +23,7 @@ object Printers { val completions = noPrinter val gadts = noPrinter val hk = noPrinter + val variances = noPrinter val incremental = noPrinter val config = noPrinter val transforms = noPrinter diff --git a/src/dotty/tools/dotc/core/TypeApplications.scala b/src/dotty/tools/dotc/core/TypeApplications.scala index c63788ec9..2c8e9902b 100644 --- a/src/dotty/tools/dotc/core/TypeApplications.scala +++ b/src/dotty/tools/dotc/core/TypeApplications.scala @@ -463,16 +463,18 @@ class TypeApplications(val self: Type) extends AnyVal { self.appliedTo(tparams map (_.typeRef)).LambdaAbstract(tparams) } - /** If this type has a base type `B[T1, ..., Tn]` where the type parameters - * of `B` match one-by-one the variances of `tparams`, convert it to + /** Test whether this type has a base type `B[T1, ..., Tn]` where the type parameters + * of `B` match one-by-one the variances of `tparams`, and where the lambda + * abstracted type * * LambdaXYZ { type Apply = B[$hkArg$0, ..., $hkArg$n] } * { type $hkArg$0 = T1; ...; type $hkArg$n = Tn } * + * satisfies predicate `p`. Try base types in the order of ther occurrence in `baseClasses`. * A type parameter matches a varianve V if it has V as its variance or if V == 0. */ - def EtaLiftTo(tparams: List[Symbol])(implicit ctx: Context): Type = { - def tryLift(bcs: List[ClassSymbol]): Type = bcs match { + def testLifted(tparams: List[Symbol], p: Type => Boolean)(implicit ctx: Context): Boolean = { + def tryLift(bcs: List[ClassSymbol]): Boolean = bcs match { case bc :: bcs1 => val tp = self.baseTypeWithArgs(bc) val targs = tp.argInfos @@ -481,19 +483,20 @@ class TypeApplications(val self: Type) extends AnyVal { param2.variance == param2.variance || param2.variance == 0 if ((tycon.typeParams corresponds tparams)(variancesMatch)) { val expanded = tycon.EtaExpand - val res = (expanded /: targs) { (partialInst, targ) => + val lifted = (expanded /: targs) { (partialInst, targ) => val tparam = partialInst.typeParams.head RefinedType(partialInst, tparam.name, targ.bounds.withVariance(tparam.variance)) } - hk.println(i"eta lifting $self --> $res") - res + ctx.traceIndented(i"eta lifting $self --> $lifted", hk) { + p(lifted) || tryLift(bcs1) + } } else tryLift(bcs1) case nil => - NoType + false } - if (tparams.isEmpty) NoType - else if (typeParams.nonEmpty) EtaExpand + if (tparams.isEmpty) false + else if (typeParams.nonEmpty) p(EtaExpand) else tryLift(self.baseClasses) } }
\ No newline at end of file diff --git a/src/dotty/tools/dotc/core/TypeComparer.scala b/src/dotty/tools/dotc/core/TypeComparer.scala index 797712459..48286fe47 100644 --- a/src/dotty/tools/dotc/core/TypeComparer.scala +++ b/src/dotty/tools/dotc/core/TypeComparer.scala @@ -454,7 +454,7 @@ class TypeComparer(initctx: Context) extends DotClass { def isHKSubType = tp2.name == tpnme.Apply && { val lambda2 = tp2.prefix.LambdaClass(forcing = true) lambda2.exists && !tp1.isLambda && - isSubType(tp1.EtaLiftTo(lambda2.typeParams), tp2.prefix) + tp1.testLifted(lambda2.typeParams, isSubType(_, tp2.prefix)) } def compareNamed = { implicit val ctx: Context = this.ctx // Dotty deviation: implicits need explicit type @@ -673,7 +673,7 @@ class TypeComparer(initctx: Context) extends DotClass { || hasMatchingMember(name2) || fourthTry(tp1, tp2) ) - || needsEtaLift(tp1, tp2) && isSubType(tp1.EtaLiftTo(tp2.typeParams), tp2) + || needsEtaLift(tp1, tp2) && tp1.testLifted(tp2.typeParams, isSubType(_, tp2)) ) } compareRefined @@ -768,7 +768,7 @@ class TypeComparer(initctx: Context) extends DotClass { isNewSubType(tp1.parent, tp2) } finally pendingRefinedBases = saved - } || needsEtaLift(tp2, tp1) && isSubType(tp1, tp2.EtaLiftTo(tp1.typeParams)) + } || needsEtaLift(tp2, tp1) && tp2.testLifted(tp1.typeParams, isSubType(tp1, _)) case AndType(tp11, tp12) => isNewSubType(tp11, tp2) || isNewSubType(tp12, tp2) case _ => diff --git a/src/dotty/tools/dotc/typer/VarianceChecker.scala b/src/dotty/tools/dotc/typer/VarianceChecker.scala index 9ce3ca0b7..5865f0133 100644 --- a/src/dotty/tools/dotc/typer/VarianceChecker.scala +++ b/src/dotty/tools/dotc/typer/VarianceChecker.scala @@ -6,6 +6,7 @@ import core._ import Types._, Contexts._, Flags._, Symbols._, Annotations._, Trees._, NameOps._ import Decorators._ import Variances._ +import config.Printers.variances /** Provides `check` method to check that all top-level definitions * in tree are variance correct. Does not recurse inside methods. @@ -77,7 +78,7 @@ class VarianceChecker()(implicit ctx: Context) { * explicitly (their TypeDefs will be passed here.) For MethodTypes, the * same is true of the parameters (ValDefs). */ - def apply(status: Option[VarianceError], tp: Type): Option[VarianceError] = ctx.traceIndented(s"variance checking $tp of $base at $variance") { + def apply(status: Option[VarianceError], tp: Type): Option[VarianceError] = ctx.traceIndented(s"variance checking $tp of $base at $variance", variances) { if (status.isDefined) status else tp match { case tp: TypeRef => |