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author | Martin Odersky <odersky@gmail.com> | 2017-03-17 15:31:42 +0100 |
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committer | Martin Odersky <odersky@gmail.com> | 2017-04-06 13:15:28 +0200 |
commit | d0823efe3ecdc0b38678e58e7de4cf2139cec847 (patch) | |
tree | 2429eaac7d416da5ade39f046ba5b6e29395eafc | |
parent | 4bfc17365518e6014895ae1aaa51517648b46df2 (diff) | |
download | dotty-d0823efe3ecdc0b38678e58e7de4cf2139cec847.tar.gz dotty-d0823efe3ecdc0b38678e58e7de4cf2139cec847.tar.bz2 dotty-d0823efe3ecdc0b38678e58e7de4cf2139cec847.zip |
Add HKTypeLambda
-rw-r--r-- | compiler/src/dotty/tools/dotc/core/Types.scala | 45 |
1 files changed, 40 insertions, 5 deletions
diff --git a/compiler/src/dotty/tools/dotc/core/Types.scala b/compiler/src/dotty/tools/dotc/core/Types.scala index fc0569e6f..be9f310b9 100644 --- a/compiler/src/dotty/tools/dotc/core/Types.scala +++ b/compiler/src/dotty/tools/dotc/core/Types.scala @@ -2397,6 +2397,7 @@ object Types { abstract class HKLambda extends CachedProxyType with LambdaType { final override def computeHash = doHash(paramNames, resType, paramInfos) + final override def underlying(implicit ctx: Context) = resType } abstract class StarLambda extends CachedGroundType with LambdaType with TermType { @@ -2657,6 +2658,30 @@ object Types { } } + class HKTypeLambda(val paramNames: List[TypeName])( + paramInfosExp: HKTypeLambda => List[TypeBounds], resultTypeExp: HKTypeLambda => Type) + extends HKLambda with TypeLambda { + type This = HKTypeLambda + def companion = HKTypeLambda + + val paramInfos: List[TypeBounds] = paramInfosExp(this) + val resType: Type = resultTypeExp(this) + + assert(resType.isInstanceOf[TermType], this) + assert(paramNames.nonEmpty) + + /** The type `[tparams := paramRefs] tp`, where `tparams` can be + * either a list of type parameter symbols or a list of lambda parameters + */ + def lifted(tparams: List[ParamInfo], tp: Type)(implicit ctx: Context): Type = + tparams match { + case LambdaParam(poly, _) :: _ => tp.subst(poly, this) + case tparams: List[Symbol @unchecked] => tp.subst(tparams, paramRefs) + } + + protected def prefixString = "HKTypeLambda" + } + /** A type lambda of the form `[X_0 B_0, ..., X_n B_n] => T` * This is used both as a type of a polymorphic method and as a type of * a higher-kinded type parameter. Variances are encoded in parameter @@ -2677,17 +2702,12 @@ object Types { type This = PolyType def companion = PolyType - /** The bounds of the type parameters */ val paramInfos: List[TypeBounds] = paramInfosExp(this) - - /** The result type of a PolyType / body of a type lambda */ val resType: Type = resultTypeExp(this) assert(resType.isInstanceOf[TermType], this) assert(paramNames.nonEmpty) - override def underlying(implicit ctx: Context) = resType - /** Merge nested polytypes into one polytype. nested polytypes are normally not supported * but can arise as temporary data structures. */ @@ -2718,6 +2738,21 @@ object Types { protected def prefixString = "PolyType" } + object HKTypeLambda extends TypeLambdaCompanion[HKTypeLambda] { + def apply(paramNames: List[TypeName])( + paramInfosExp: HKTypeLambda => List[TypeBounds], + resultTypeExp: HKTypeLambda => Type)(implicit ctx: Context): HKTypeLambda = { + unique(new HKTypeLambda(paramNames)(paramInfosExp, resultTypeExp)) + } + + def unapply(tl: HKTypeLambda): Some[(List[LambdaParam], Type)] = + Some((tl.typeParams, tl.resType)) + + def any(n: Int)(implicit ctx: Context) = + apply(syntheticParamNames(n))( + pt => List.fill(n)(TypeBounds.empty), pt => defn.AnyType) + } + object PolyType extends TypeLambdaCompanion[PolyType] { def apply(paramNames: List[TypeName])( paramInfosExp: PolyType => List[TypeBounds], |