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author | Martin Odersky <odersky@gmail.com> | 2017-04-09 19:08:52 +0200 |
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committer | Martin Odersky <odersky@gmail.com> | 2017-04-09 19:09:20 +0200 |
commit | 14fde01d3576f60585d59d2b00cce8b3c177b236 (patch) | |
tree | e257b31cc9a5ca33ccebcd702cce92dfad450162 /compiler/src/dotty/tools/dotc/typer/Typer.scala | |
parent | b8bb34dd0ea68cfed09ed54604f659a787037d2d (diff) | |
download | dotty-14fde01d3576f60585d59d2b00cce8b3c177b236.tar.gz dotty-14fde01d3576f60585d59d2b00cce8b3c177b236.tar.bz2 dotty-14fde01d3576f60585d59d2b00cce8b3c177b236.zip |
Fix #2192: Fullow supertypes when determining whether an expect type is a function type
Diffstat (limited to 'compiler/src/dotty/tools/dotc/typer/Typer.scala')
-rw-r--r-- | compiler/src/dotty/tools/dotc/typer/Typer.scala | 14 |
1 files changed, 12 insertions, 2 deletions
diff --git a/compiler/src/dotty/tools/dotc/typer/Typer.scala b/compiler/src/dotty/tools/dotc/typer/Typer.scala index 2760ceba9..a7b8200b5 100644 --- a/compiler/src/dotty/tools/dotc/typer/Typer.scala +++ b/compiler/src/dotty/tools/dotc/typer/Typer.scala @@ -1932,13 +1932,23 @@ class Typer extends Namer with TypeAssigner with Applications with Implicits wit adapt(typed(original, WildcardType), pt, EmptyTree) } case wtp: MethodType if !pt.isInstanceOf[SingletonType] => + // Follow proxies and approximate type paramrefs by their upper bound + // in the current constraint in order to figure out robustly + // whether an expected type is some sort of function type. + def underlyingRefined(tp: Type): Type = tp.stripTypeVar match { + case tp: RefinedType => tp + case tp: TypeParamRef => underlyingRefined(ctx.typeComparer.bounds(tp).hi) + case tp: TypeProxy => underlyingRefined(tp.superType) + case _ => tp + } + val ptNorm = underlyingRefined(pt) val arity = - if (defn.isFunctionType(pt)) + if (defn.isFunctionType(ptNorm)) if (!isFullyDefined(pt, ForceDegree.none) && isFullyDefined(wtp, ForceDegree.none)) // if method type is fully defined, but expected type is not, // prioritize method parameter types as parameter types of the eta-expanded closure 0 - else defn.functionArity(pt) + else defn.functionArity(ptNorm) else if (pt eq AnyFunctionProto) wtp.paramInfos.length else -1 if (arity >= 0 && !tree.symbol.isConstructor) |