From d5ef867b1f89c79f8620129693e4f1e9bc6f617c Mon Sep 17 00:00:00 2001 From: Martin Odersky Date: Thu, 18 Aug 2016 17:24:11 +0200 Subject: Refinements to auto tupling There's a nasty interaction with auto-tupling and trying to insert an implicit on the qualifier of a call. If the original call fails, we need to "undo" any auto-tupling decisions in calls where an implicit is inserted on the qualifier. Also: Needed to fix canAutoTuple test so that Scala2 feature is checked instead of dotty's. Also: Drop features in dotty.language that duplicate those in scala.language. --- src/dotty/language.scala | 6 +-- src/dotty/tools/dotc/core/TypeOps.scala | 4 +- src/dotty/tools/dotc/typer/Applications.scala | 32 +++++++---- src/dotty/tools/dotc/typer/Typer.scala | 19 +++---- tests/neg/autoTuplingTest.scala | 2 - tests/pending/pos/t2913.scala | 55 ------------------- tests/pos/t2913.scala | 78 +++++++++++++++++++++++++++ 7 files changed, 112 insertions(+), 84 deletions(-) delete mode 100644 tests/pending/pos/t2913.scala create mode 100644 tests/pos/t2913.scala diff --git a/src/dotty/language.scala b/src/dotty/language.scala index 96250a9f2..0ed75bd26 100644 --- a/src/dotty/language.scala +++ b/src/dotty/language.scala @@ -4,13 +4,9 @@ object language { class Feature - /** Allow higher-kinded type syntax (not yet checked) */ - val higherKinds = new Feature - /** Keep union types */ val keepUnions = new Feature - /** No auto tupling */ - val noAutoTupling = new Feature + val f = "".contains("", (_: Int)) } diff --git a/src/dotty/tools/dotc/core/TypeOps.scala b/src/dotty/tools/dotc/core/TypeOps.scala index 93b1b1f02..b69ce2536 100644 --- a/src/dotty/tools/dotc/core/TypeOps.scala +++ b/src/dotty/tools/dotc/core/TypeOps.scala @@ -493,7 +493,7 @@ trait TypeOps { this: Context => // TODO: Make standalone object. */ def featureEnabled(owner: ClassSymbol, feature: TermName): Boolean = { def toPrefix(sym: Symbol): String = - if (!sym.exists || (sym eq defn.LanguageModuleClass) || (sym eq defn.Scala2LanguageModuleRef)) "" + if (!sym.exists || (sym eq defn.LanguageModuleClass) || (sym eq defn.Scala2LanguageModuleClass)) "" else toPrefix(sym.owner) + sym.name + "." def featureName = toPrefix(owner) + feature def hasImport(implicit ctx: Context): Boolean = { @@ -512,7 +512,7 @@ trait TypeOps { this: Context => // TODO: Make standalone object. /** Is auto-tupling enabled? */ def canAutoTuple = - !featureEnabled(defn.LanguageModuleClass, nme.noAutoTupling) + !featureEnabled(defn.Scala2LanguageModuleClass, nme.noAutoTupling) def scala2Mode = featureEnabled(defn.LanguageModuleClass, nme.Scala2) diff --git a/src/dotty/tools/dotc/typer/Applications.scala b/src/dotty/tools/dotc/typer/Applications.scala index c8f41b7fa..efd12cb5e 100644 --- a/src/dotty/tools/dotc/typer/Applications.scala +++ b/src/dotty/tools/dotc/typer/Applications.scala @@ -541,17 +541,29 @@ trait Applications extends Compatibility { self: Typer with Dynamic => def typedApply(tree: untpd.Apply, pt: Type)(implicit ctx: Context): Tree = { + /** Try same application with an implicit inserted around the qualifier of the function + * part. Return an optional value to indicate success. + */ + def tryWithImplicitOnQualifier(fun1: Tree, proto: FunProto)(implicit ctx: Context): Option[Tree] = + tryInsertImplicitOnQualifier(fun1, proto) flatMap { fun2 => + tryEither { implicit ctx => + Some(typedApply( + cpy.Apply(tree)(untpd.TypedSplice(fun2), proto.typedArgs map untpd.TypedSplice), + pt)): Option[Tree] + } { (_, _) => None } + } + def realApply(implicit ctx: Context): Tree = track("realApply") { - var proto = new FunProto(tree.args, IgnoredProto(pt), this)(argCtx(tree)) - val fun1 = typedExpr(tree.fun, proto) + val originalProto = new FunProto(tree.args, IgnoredProto(pt), this)(argCtx(tree)) + val fun1 = typedExpr(tree.fun, originalProto) - // Warning: The following line is dirty and fragile. We record that auto-tupling was demanded as + // Warning: The following lines are dirty and fragile. We record that auto-tupling was demanded as // a side effect in adapt. If it was, we assume the tupled proto-type in the rest of the application. // This crucially relies on he fact that `proto` is used only in a single call of `adapt`, // otherwise we would get possible cross-talk between different `adapt` calls using the same // prototype. A cleaner alternative would be to return a modified prototype from `adapt` together with // a modified tree but this would be more convoluted and less efficient. - if (proto.isTupled) proto = proto.tupled + val proto = if (originalProto.isTupled) originalProto.tupled else originalProto // If some of the application's arguments are function literals without explicitly declared // parameter types, relate the normalized result type of the application with the @@ -580,13 +592,11 @@ trait Applications extends Compatibility { self: Typer with Dynamic => val result = app.result convertNewGenericArray(ConstFold(result)) } { (failedVal, failedState) => - val fun2 = tryInsertImplicitOnQualifier(fun1, proto) - if (fun1 eq fun2) { - failedState.commit() - failedVal - } else typedApply( - cpy.Apply(tree)(untpd.TypedSplice(fun2), proto.typedArgs map untpd.TypedSplice), pt) - } + def fail = { failedState.commit(); failedVal } + tryWithImplicitOnQualifier(fun1, originalProto).getOrElse( + if (proto eq originalProto) fail + else tryWithImplicitOnQualifier(fun1, proto).getOrElse(fail)) + } case _ => handleUnexpectedFunType(tree, fun1) } diff --git a/src/dotty/tools/dotc/typer/Typer.scala b/src/dotty/tools/dotc/typer/Typer.scala index 2b690ef51..34cd5448b 100644 --- a/src/dotty/tools/dotc/typer/Typer.scala +++ b/src/dotty/tools/dotc/typer/Typer.scala @@ -1445,26 +1445,27 @@ class Typer extends Namer with TypeAssigner with Applications with Implicits wit val sel = typedSelect(untpd.Select(untpd.TypedSplice(tree), nme.apply), pt) if (sel.tpe.isError) sel else adapt(sel, pt) } { (failedTree, failedState) => - val tree1 = tryInsertImplicitOnQualifier(tree, pt) - if (tree1 eq tree) fallBack(failedTree, failedState) - else adapt(tree1, pt) - } + tryInsertImplicitOnQualifier(tree, pt) match { + case Some(tree1) => adapt(tree1, pt) + case none => fallBack(failedTree, failedState) + } + } /** If this tree is a select node `qual.name`, try to insert an implicit conversion * `c` around `qual` so that `c(qual).name` conforms to `pt`. If that fails * return `tree` itself. */ - def tryInsertImplicitOnQualifier(tree: Tree, pt: Type)(implicit ctx: Context): Tree = ctx.traceIndented(i"try insert impl on qualifier $tree $pt") { + def tryInsertImplicitOnQualifier(tree: Tree, pt: Type)(implicit ctx: Context): Option[Tree] = ctx.traceIndented(i"try insert impl on qualifier $tree $pt") { tree match { case Select(qual, name) => val qualProto = SelectionProto(name, pt, NoViewsAllowed) tryEither { implicit ctx => val qual1 = adaptInterpolated(qual, qualProto, EmptyTree) - if ((qual eq qual1) || ctx.reporter.hasErrors) tree - else typedSelect(cpy.Select(tree)(untpd.TypedSplice(qual1), name), pt) - } { (_, _) => tree + if ((qual eq qual1) || ctx.reporter.hasErrors) None + else Some(typedSelect(cpy.Select(tree)(untpd.TypedSplice(qual1), name), pt)) + } { (_, _) => None } - case _ => tree + case _ => None } } diff --git a/tests/neg/autoTuplingTest.scala b/tests/neg/autoTuplingTest.scala index 37136b760..62f10b3ea 100644 --- a/tests/neg/autoTuplingTest.scala +++ b/tests/neg/autoTuplingTest.scala @@ -1,5 +1,3 @@ -import dotty.language.noAutoTupling - object autoTuplingNeg2 { val x = Some(1, 2) // error: too many arguments for method apply: (x: A)Some[A] diff --git a/tests/pending/pos/t2913.scala b/tests/pending/pos/t2913.scala deleted file mode 100644 index 21700e71a..000000000 --- a/tests/pending/pos/t2913.scala +++ /dev/null @@ -1,55 +0,0 @@ -import language.noAutoTupling // try with on and off - -class A { - def foo(a: Int) = 0 -} - -class RichA { - def foo(a: String) = 0 - def foo(a: String, b: String) = 0 - def foo() = 0 -} - -object Test { - - implicit def AToRichA(a: A): RichA = new RichA - - val a = new A - a.foo() - a.foo(1) - - a.foo("") // Without implicits, a type error regarding invalid argument types is generated at `""`. This is - // the same position as an argument, so the 'second try' typing with an Implicit View is tried, - // and AToRichA(a).foo("") is found. - // - // My reading of the spec "7.3 Views" is that `a.foo` denotes a member of `a`, so the view should - // not be triggered. - // - // But perhaps the implementation was changed to solve See https://lampsvn.epfl.ch/trac/scala/ticket/1756 - - a.foo("a", "b") // Without implicits, a type error regarding invalid arity is generated at `foo("", "")`. - // Typers#tryTypedApply:3274 only checks if the error is as the same position as `foo`, `"a"`, or `"b"`. - // None of these po -} - -// t0851 is essentially the same: -object test1 { - case class Foo[T,T2](f : (T,T2) => String) extends (((T,T2)) => String){ - def apply(t : T) = (s:T2) => f(t,s) - def apply(p : (T,T2)) = f(p._1,p._2) - } - implicit def g[T](f : (T,String) => String): test1.Foo[T,String] = Foo(f) - def main(args : Array[String]) : Unit = { - val f = (x:Int,s:String) => s + x - println(f(1)) - () - } -} -object Main { - def main(args : Array[String]): Unit = { - val fn = (a : Int, str : String) => "a: " + a + ", str: " + str - implicit def fx[T](f : (T,String) => String): T => String = (x:T) => f(x,null) - println(fn(1)) - () - } -} diff --git a/tests/pos/t2913.scala b/tests/pos/t2913.scala new file mode 100644 index 000000000..fa91e6f41 --- /dev/null +++ b/tests/pos/t2913.scala @@ -0,0 +1,78 @@ + +class A { + def foo(a: Int) = 0 +} + +class RichA { + def foo(a: String) = 0 + def foo(a: String, b: String) = 0 + def foo() = 0 +} + +object TestNoAutoTupling { + import language.noAutoTupling // try with on and off + + implicit def AToRichA(a: A): RichA = new RichA + + val a = new A + a.foo() + a.foo(1) + + a.foo("") // Without implicits, a type error regarding invalid argument types is generated at `""`. This is + // the same position as an argument, so the 'second try' typing with an Implicit View is tried, + // and AToRichA(a).foo("") is found. + // + // My reading of the spec "7.3 Views" is that `a.foo` denotes a member of `a`, so the view should + // not be triggered. + // + // But perhaps the implementation was changed to solve See https://lampsvn.epfl.ch/trac/scala/ticket/1756 + + a.foo("a", "b") // Without implicits, a type error regarding invalid arity is generated at `foo("", "")`. + // Typers#tryTypedApply:3274 only checks if the error is as the same position as `foo`, `"a"`, or `"b"`. + // None of these po +} + +// t0851 is essentially the same: +object test1 { + case class Foo[T,T2](f : (T,T2) => String) extends (((T,T2)) => String){ + def apply(t : T) = (s:T2) => f(t,s) + def apply(p : (T,T2)) = f(p._1,p._2) + } + implicit def g[T](f : (T,String) => String): test1.Foo[T,String] = Foo(f) + def main(args : Array[String]) : Unit = { + val f = (x:Int,s:String) => s + x + println(f(1)) + () + } +} +object Main { + def main(args : Array[String]): Unit = { + val fn = (a : Int, str : String) => "a: " + a + ", str: " + str + implicit def fx[T](f : (T,String) => String): T => String = (x:T) => f(x,null) + println(fn(1)) + () + } +} + +object TestWithAutoTuling { + + implicit def AToRichA(a: A): RichA = new RichA + + val a = new A + a.foo() + a.foo(1) + + a.foo("") // Without implicits, a type error regarding invalid argument types is generated at `""`. This is + // the same position as an argument, so the 'second try' typing with an Implicit View is tried, + // and AToRichA(a).foo("") is found. + // + // My reading of the spec "7.3 Views" is that `a.foo` denotes a member of `a`, so the view should + // not be triggered. + // + // But perhaps the implementation was changed to solve See https://lampsvn.epfl.ch/trac/scala/ticket/1756 + + a.foo("a", "b") // Without implicits, a type error regarding invalid arity is generated at `foo("", "")`. + // Typers#tryTypedApply:3274 only checks if the error is as the same position as `foo`, `"a"`, or `"b"`. + // None of these po +} + -- cgit v1.2.3