diff options
Diffstat (limited to 'src/dotty/tools/dotc/core/Types.scala')
| -rw-r--r-- | src/dotty/tools/dotc/core/Types.scala | 38 |
1 files changed, 36 insertions, 2 deletions
diff --git a/src/dotty/tools/dotc/core/Types.scala b/src/dotty/tools/dotc/core/Types.scala index 403b49da6..2fa4f94c1 100644 --- a/src/dotty/tools/dotc/core/Types.scala +++ b/src/dotty/tools/dotc/core/Types.scala @@ -2131,9 +2131,43 @@ object Types { this } - def derivedRefinedType(parent: Type, refinedName: Name, refinedInfo: Type)(implicit ctx: Context): RefinedType = + def betaReduce(implicit ctx: Context): Type = refinedInfo match { + case TypeAlias(alias) => + def instantiate(rt: RecType) = new TypeMap { + def apply(t: Type) = t match { + case TypeRef(RecThis(`rt`), `refinedName`) => alias + case tp: TypeRef => + val pre1 = apply(tp.prefix) + if (pre1 ne tp.prefix) tp.newLikeThis(pre1) else tp + case _ => mapOver(t) + } + } + def substAlias(tp: Type): Type = tp.safeDealias match { + case tp @ RefinedType(p, rname, rinfo) if tp.isTypeParam => + if (rname == refinedName) p // check bounds? + else tp.derivedRefinedType(substAlias(p), rname, rinfo) + case tp: RecType => + val p1 = substAlias(tp.parent) + if (p1 ne tp.parent) tp.rebind(instantiate(tp)(p1)) + else tp + case _ => + tp + } + val reduced = substAlias(parent) + if (reduced ne parent) { + hk.println(i"REDUCE $this ----> ${reduced}") + reduced + } + else this + case _ => + this + } + + def derivedRefinedType(parent: Type, refinedName: Name, refinedInfo: Type)(implicit ctx: Context): Type = if ((parent eq this.parent) && (refinedName eq this.refinedName) && (refinedInfo eq this.refinedInfo)) this - else RefinedType(parent, refinedName, rt => refinedInfo.substRefinedThis(this, RefinedThis(rt))) + else + RefinedType(parent, refinedName, rt => refinedInfo.substRefinedThis(this, RefinedThis(rt))) + .betaReduce /** Add this refinement to `parent`, provided If `refinedName` is a member of `parent`. */ def wrapIfMember(parent: Type)(implicit ctx: Context): Type = |