diff options
Diffstat (limited to 'src/dotty/tools/dotc/core')
-rw-r--r-- | src/dotty/tools/dotc/core/Types.scala | 17 |
1 files changed, 14 insertions, 3 deletions
diff --git a/src/dotty/tools/dotc/core/Types.scala b/src/dotty/tools/dotc/core/Types.scala index 38913a7d0..8b27db05d 100644 --- a/src/dotty/tools/dotc/core/Types.scala +++ b/src/dotty/tools/dotc/core/Types.scala @@ -2527,6 +2527,11 @@ object Types { case _: MethodType => true case _ => false } + + /** Is this polytype a higher-kinded type lambda as opposed to a polymorphic? + * method type? Only type lambdas get created with variances, that's how we can tell. + */ + def isTypeLambda: Boolean = variances.nonEmpty /** PolyParam references to all type parameters of this type */ lazy val paramRefs: List[PolyParam] = paramNames.indices.toList.map(PolyParam(this, _)) @@ -2914,9 +2919,15 @@ object Types { def instantiate(fromBelow: Boolean)(implicit ctx: Context): Type = { val inst = ctx.typeComparer.instanceType(origin, fromBelow) if (ctx.typerState.isGlobalCommittable) - assert(!inst.isInstanceOf[PolyParam], i"bad inst $this := $inst, constr = ${ctx.typerState.constraint}") - // If this fails, you might want to turn on Config.debugCheckConstraintsClosed - // to help find the root of the problem. + inst match { + case inst: PolyParam => + assert(inst.binder.isTypeLambda, i"bad inst $this := $inst, constr = ${ctx.typerState.constraint}") + // If this fails, you might want to turn on Config.debugCheckConstraintsClosed + // to help find the root of the problem. + // Note: Parameters of type lambdas are excluded from the assertion because + // they might arise from ill-kinded code. See #1652 + case _ => + } instantiateWith(inst) } |