diff options
| -rw-r--r-- | src/compiler/scala/tools/nsc/typechecker/Contexts.scala | 25 | ||||
| -rw-r--r-- | src/compiler/scala/tools/nsc/typechecker/Typers.scala | 27 | ||||
| -rw-r--r-- | test/files/run/virtpatmat_stringinterp.check | 1 | ||||
| -rw-r--r-- | test/files/run/virtpatmat_stringinterp.flags | 1 | ||||
| -rw-r--r-- | test/files/run/virtpatmat_stringinterp.scala | 13 |
5 files changed, 62 insertions, 5 deletions
diff --git a/src/compiler/scala/tools/nsc/typechecker/Contexts.scala b/src/compiler/scala/tools/nsc/typechecker/Contexts.scala index fe1c90fe67..e2d4efab83 100644 --- a/src/compiler/scala/tools/nsc/typechecker/Contexts.scala +++ b/src/compiler/scala/tools/nsc/typechecker/Contexts.scala @@ -67,6 +67,7 @@ trait Contexts { self: Analyzer => val c = sc.make(unit, tree, sc.owner, sc.scope, sc.imports) if (erasedTypes) c.setThrowErrors() else c.setReportErrors() c.implicitsEnabled = !erasedTypes + c.enrichmentEnabled = c.implicitsEnabled c } @@ -106,7 +107,7 @@ trait Contexts { self: Analyzer => var depth: Int = 0 var imports: List[ImportInfo] = List() // currently visible imports var openImplicits: List[(Type,Tree)] = List() // types for which implicit arguments - // are currently searched + // are currently searched // for a named application block (Tree) the corresponding NamedApplyInfo var namedApplyBlockInfo: Option[(Tree, NamedApplyInfo)] = None var prefix: Type = NoPrefix @@ -120,6 +121,7 @@ trait Contexts { self: Analyzer => var diagnostic: List[String] = Nil // these messages are printed when issuing an error var implicitsEnabled = false var macrosEnabled = true + var enrichmentEnabled = false // to selectively allow enrichment in patterns, where other kinds of implicit conversions are not allowed var checking = false var retyping = false @@ -192,8 +194,25 @@ trait Contexts { self: Analyzer => def withImplicitsDisabled[T](op: => T): T = { val saved = implicitsEnabled implicitsEnabled = false + val savedP = enrichmentEnabled + enrichmentEnabled = false try op - finally implicitsEnabled = saved + finally { + implicitsEnabled = saved + enrichmentEnabled = savedP + } + } + + def withImplicitsDisabledAllowEnrichment[T](op: => T): T = { + val saved = implicitsEnabled + implicitsEnabled = false + val savedP = enrichmentEnabled + enrichmentEnabled = true + try op + finally { + implicitsEnabled = saved + enrichmentEnabled = savedP + } } def withMacrosEnabled[T](op: => T): T = { @@ -246,6 +265,7 @@ trait Contexts { self: Analyzer => c.typingIndentLevel = typingIndentLevel c.implicitsEnabled = this.implicitsEnabled c.macrosEnabled = this.macrosEnabled + c.enrichmentEnabled = this.enrichmentEnabled c.checking = this.checking c.retyping = this.retyping c.openImplicits = this.openImplicits @@ -298,6 +318,7 @@ trait Contexts { self: Analyzer => def makeImplicit(reportAmbiguousErrors: Boolean) = { val c = makeSilent(reportAmbiguousErrors) c.implicitsEnabled = false + c.enrichmentEnabled = false c } diff --git a/src/compiler/scala/tools/nsc/typechecker/Typers.scala b/src/compiler/scala/tools/nsc/typechecker/Typers.scala index 2b7c8e8304..a6a670f163 100644 --- a/src/compiler/scala/tools/nsc/typechecker/Typers.scala +++ b/src/compiler/scala/tools/nsc/typechecker/Typers.scala @@ -1171,7 +1171,7 @@ trait Typers extends Modes with Adaptations with PatMatVirtualiser { && !qtpe.typeSymbol.isBottomClass && qtpe != WildcardType && !qual.isInstanceOf[ApplyImplicitView] // don't chain views - && context.implicitsEnabled + && (context.implicitsEnabled || context.enrichmentEnabled) // Elaborating `context.implicitsEnabled`: // don't try to adapt a top-level type that's the subject of an implicit search // this happens because, if isView, typedImplicit tries to apply the "current" implicit value to @@ -4063,7 +4063,10 @@ trait Typers extends Modes with Adaptations with PatMatVirtualiser { } else { member(qual, name) } - if (sym == NoSymbol && name != nme.CONSTRUCTOR && (mode & EXPRmode) != 0) { + + // symbol not found? --> try to convert implicitly to a type that does have the required member + // added `| PATTERNmode` to allow enrichment in patterns (so we can add e.g., an xml member to StringContext, which in turn has an unapply[Seq] method) + if (sym == NoSymbol && name != nme.CONSTRUCTOR && (mode & (EXPRmode | PATTERNmode)) != 0) { val qual1 = if (member(qual, name) != NoSymbol) qual else adaptToMemberWithArgs(tree, qual, name, mode, true, true) @@ -4071,6 +4074,7 @@ trait Typers extends Modes with Adaptations with PatMatVirtualiser { if (qual1 ne qual) return typed(treeCopy.Select(tree, qual1, name), mode, pt) } + if (!reallyExists(sym)) { if (context.owner.enclosingTopLevelClass.isJavaDefined && name.isTypeName) { val tree1 = atPos(tree.pos) { gen.convertToSelectFromType(qual, name) } @@ -4806,6 +4810,8 @@ trait Typers extends Modes with Adaptations with PatMatVirtualiser { ptLine("typing %s: pt = %s".format(ptTree(tree), pt), "undetparams" -> context.undetparams, "implicitsEnabled" -> context.implicitsEnabled, + "enrichmentEnabled" -> context.enrichmentEnabled, + "mode" -> modeString(mode), "silent" -> context.bufferErrors, "context.owner" -> context.owner ) @@ -4909,7 +4915,22 @@ trait Typers extends Modes with Adaptations with PatMatVirtualiser { // We disable implicits because otherwise some constructs will // type check which should not. The pattern matcher does not // perform implicit conversions in an attempt to consummate a match. - context.withImplicitsDisabled(typed(tree, PATTERNmode, pt)) + + // on the one hand, + // "abc" match { case Seq('a', 'b', 'c') => true } + // should be ruled out statically, otherwise this is a runtime + // error both because there is an implicit from String to Seq + // (even though such implicits are not used by the matcher) and + // because the typer is fine with concluding that "abc" might + // be of type "String with Seq[T]" and thus eligible for a call + // to unapplySeq. + + // on the other hand, we want to be able to use implicits to add members retro-actively (e.g., add xml to StringContext) + + // as a compromise, context.enrichmentEnabled tells adaptToMember to go ahead and enrich, + // but arbitrary conversions (in adapt) are disabled + // TODO: can we achieve the pattern matching bit of the string interpolation SIP without this? + context.withImplicitsDisabledAllowEnrichment(typed(tree, PATTERNmode, pt)) } /** Types a (fully parameterized) type tree */ diff --git a/test/files/run/virtpatmat_stringinterp.check b/test/files/run/virtpatmat_stringinterp.check new file mode 100644 index 0000000000..7927f4f2d9 --- /dev/null +++ b/test/files/run/virtpatmat_stringinterp.check @@ -0,0 +1 @@ +Node(1) diff --git a/test/files/run/virtpatmat_stringinterp.flags b/test/files/run/virtpatmat_stringinterp.flags new file mode 100644 index 0000000000..0612c4f8ff --- /dev/null +++ b/test/files/run/virtpatmat_stringinterp.flags @@ -0,0 +1 @@ +-Xexperimental -Yvirtpatmat
\ No newline at end of file diff --git a/test/files/run/virtpatmat_stringinterp.scala b/test/files/run/virtpatmat_stringinterp.scala new file mode 100644 index 0000000000..213712f17a --- /dev/null +++ b/test/files/run/virtpatmat_stringinterp.scala @@ -0,0 +1,13 @@ +object Test extends App { + case class Node(x: Int) + + implicit def sc2xml(sc: StringContext): XMLContext = new XMLContext(sc) + class XMLContext(sc: StringContext) { + object xml { + def unapplySeq(xml: Node): Option[Seq[Node]] = Some(List(Node(1))) + } + } + + val x: Node = Node(0) + x match { case xml"""<foo arg=$a/>""" => println(a) } +}
\ No newline at end of file |