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author | James Iry <jamesiry@gmail.com> | 2013-02-07 21:39:12 -0800 |
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committer | James Iry <jamesiry@gmail.com> | 2013-02-07 21:39:12 -0800 |
commit | 4c08eb604f6a23077fd1c65d0bb073ea94389961 (patch) | |
tree | 1168b9588c803586d459059b91bdc7d87130ec35 /src | |
parent | 6bcb830c080c846a7ad4bf5e1949f6b2d02d45fe (diff) | |
parent | 55c9b9c280ac9bc36bbac09397c7646f8dcf4583 (diff) | |
download | scala-4c08eb604f6a23077fd1c65d0bb073ea94389961.tar.gz scala-4c08eb604f6a23077fd1c65d0bb073ea94389961.tar.bz2 scala-4c08eb604f6a23077fd1c65d0bb073ea94389961.zip |
Merge pull request #2088 from retronym/ticket/6146
SI-6146 More accurate prefixes for sealed subtypes.
Diffstat (limited to 'src')
-rw-r--r-- | src/compiler/scala/tools/nsc/interpreter/IMain.scala | 4 | ||||
-rw-r--r-- | src/compiler/scala/tools/nsc/typechecker/PatternMatching.scala | 4 | ||||
-rw-r--r-- | src/reflect/scala/reflect/internal/Types.scala | 51 |
3 files changed, 54 insertions, 5 deletions
diff --git a/src/compiler/scala/tools/nsc/interpreter/IMain.scala b/src/compiler/scala/tools/nsc/interpreter/IMain.scala index a55f0af116..bed8570bd0 100644 --- a/src/compiler/scala/tools/nsc/interpreter/IMain.scala +++ b/src/compiler/scala/tools/nsc/interpreter/IMain.scala @@ -262,7 +262,9 @@ class IMain(initialSettings: Settings, protected val out: JPrintWriter) extends protected def newCompiler(settings: Settings, reporter: Reporter): ReplGlobal = { settings.outputDirs setSingleOutput virtualDirectory settings.exposeEmptyPackage.value = true - new Global(settings, reporter) with ReplGlobal + new Global(settings, reporter) with ReplGlobal { + override def toString: String = "<global>" + } } /** Parent classloader. Overridable. */ diff --git a/src/compiler/scala/tools/nsc/typechecker/PatternMatching.scala b/src/compiler/scala/tools/nsc/typechecker/PatternMatching.scala index 452957745a..4a765ea22e 100644 --- a/src/compiler/scala/tools/nsc/typechecker/PatternMatching.scala +++ b/src/compiler/scala/tools/nsc/typechecker/PatternMatching.scala @@ -2818,7 +2818,9 @@ trait PatternMatching extends Transform with TypingTransformers with ast.TreeDSL // compare to the fully known type `tp` (modulo abstract types), // so that we can rule out stuff like: sealed trait X[T]; class XInt extends X[Int] --> XInt not valid when enumerating X[String] // however, must approximate abstract types in - val subTp = appliedType(pre.memberType(sym), sym.typeParams.map(_ => WildcardType)) + + val memberType = nestedMemberType(sym, pre, tpApprox.typeSymbol.owner) + val subTp = appliedType(memberType, sym.typeParams.map(_ => WildcardType)) val subTpApprox = typer.infer.approximateAbstracts(subTp) // TODO: needed? // patmatDebug("subtp"+(subTpApprox <:< tpApprox, subTpApprox, tpApprox)) if (subTpApprox <:< tpApprox) Some(checkableType(subTp)) diff --git a/src/reflect/scala/reflect/internal/Types.scala b/src/reflect/scala/reflect/internal/Types.scala index 0dd98fb6ae..b708ca0fd6 100644 --- a/src/reflect/scala/reflect/internal/Types.scala +++ b/src/reflect/scala/reflect/internal/Types.scala @@ -586,9 +586,9 @@ trait Types extends api.Types { self: SymbolTable => * Expands type aliases and converts higher-kinded TypeRefs to PolyTypes. * Functions on types are also implemented as PolyTypes. * - * Example: (in the below, <List> is the type constructor of List) - * TypeRef(pre, <List>, List()) is replaced by - * PolyType(X, TypeRef(pre, <List>, List(X))) + * Example: (in the below, `<List>` is the type constructor of List) + * TypeRef(pre, `<List>`, List()) is replaced by + * PolyType(X, TypeRef(pre, `<List>`, List(X))) */ def normalize = this // @MAT @@ -4974,6 +4974,51 @@ trait Types extends api.Types { self: SymbolTable => } } + /** + * A more persistent version of `Type#memberType` which does not require + * that the symbol is a direct member of the prefix. + * + * For instance: + * + * {{{ + * class C[T] { + * sealed trait F[A] + * object X { + * object S1 extends F[T] + * } + * class S2 extends F[T] + * } + * object O extends C[Int] { + * def foo(f: F[Int]) = f match {...} // need to enumerate sealed subtypes of the scrutinee here. + * } + * class S3 extends O.F[String] + * + * nestedMemberType(<S1>, <O.type>, <C>) = O.X.S1.type + * nestedMemberType(<S2>, <O.type>, <C>) = O.S2.type + * nestedMemberType(<S3>, <O.type>, <C>) = S3.type + * }}} + * + * @param sym The symbol of the subtype + * @param pre The prefix from which the symbol is seen + * @param owner + */ + def nestedMemberType(sym: Symbol, pre: Type, owner: Symbol): Type = { + def loop(tp: Type): Type = + if (tp.isTrivial) tp + else if (tp.prefix.typeSymbol isNonBottomSubClass owner) { + val widened = tp match { + case _: ConstantType => tp // Java enum constants: don't widen to the enum type! + case _ => tp.widen // C.X.type widens to C.this.X.type, otherwise `tp asSeenFrom (pre, C)` has no effect. + } + widened asSeenFrom (pre, tp.typeSymbol.owner) + } + else loop(tp.prefix) memberType tp.typeSymbol + + val result = loop(sym.tpeHK) + assert(sym.isTerm || result.typeSymbol == sym, s"($result).typeSymbol = ${result.typeSymbol}; expected ${sym}") + result + } + /** The most deeply nested owner that contains all the symbols * of thistype or prefixless typerefs/singletype occurrences in given type. */ |