diff options
Diffstat (limited to 'src/dotty/tools/dotc/core/Types.scala')
| -rw-r--r-- | src/dotty/tools/dotc/core/Types.scala | 11 |
1 files changed, 10 insertions, 1 deletions
diff --git a/src/dotty/tools/dotc/core/Types.scala b/src/dotty/tools/dotc/core/Types.scala index 38ed09ebd..4f740d2e5 100644 --- a/src/dotty/tools/dotc/core/Types.scala +++ b/src/dotty/tools/dotc/core/Types.scala @@ -965,6 +965,15 @@ object Types { def map(tm: TypeMap): ProtoType } + /** Implementations of this trait cache the resukts of `narrow`. */ + trait NarrowCached extends Type { + private var myNarrow: TermRef = null + override def narrow(implicit ctx: Context): TermRef = { + if (myNarrow eq null) myNarrow = super.narrow + myNarrow + } + } + // --- NamedTypes ------------------------------------------------------------------ /** A NamedType of the form Prefix # name */ @@ -1408,7 +1417,7 @@ object Types { abstract case class MethodType(paramNames: List[TermName], paramTypes: List[Type]) (resultTypeExp: MethodType => Type) - extends CachedGroundType with BindingType with TermType with MethodOrPoly { thisMethodType => + extends CachedGroundType with BindingType with TermType with MethodOrPoly with NarrowCached { thisMethodType => override val resultType = resultTypeExp(this) assert(resultType != NoType) |