diff options
Diffstat (limited to 'src/compiler')
-rw-r--r-- | src/compiler/scala/tools/nsc/transform/patmat/PatternExpander.scala | 18 | ||||
-rw-r--r-- | src/compiler/scala/tools/nsc/transform/patmat/ScalacPatternExpanders.scala | 34 |
2 files changed, 36 insertions, 16 deletions
diff --git a/src/compiler/scala/tools/nsc/transform/patmat/PatternExpander.scala b/src/compiler/scala/tools/nsc/transform/patmat/PatternExpander.scala index e84ccbf754..1916050dd8 100644 --- a/src/compiler/scala/tools/nsc/transform/patmat/PatternExpander.scala +++ b/src/compiler/scala/tools/nsc/transform/patmat/PatternExpander.scala @@ -86,9 +86,25 @@ trait PatternExpander[Pattern, Type] { * @param fixed The non-sequence types which are extracted * @param repeated The sequence type which is extracted */ - final case class Extractor(whole: Type, fixed: List[Type], repeated: Repeated) { + final case class Extractor(whole: Type, fixed: List[Type], repeated: Repeated, typeOfSinglePattern: Type) { require(whole != NoType, s"expandTypes($whole, $fixed, $repeated)") + /** A pattern with arity-1 that doesn't match the arity of the Product-like result of the `get` method, + * will match that result in its entirety. Example: + * + * {{{ + * warning: there was one deprecation warning; re-run with -deprecation for details + * scala> object Extractor { def unapply(a: Any): Option[(Int, String)] = Some((1, "2")) } + * defined object Extractor + * + * scala> "" match { case Extractor(x: Int, y: String) => } + * + * scala> "" match { case Extractor(xy : (Int, String)) => } + * warning: there was one deprecation warning; re-run with -deprecation for details + * }}} + * */ + def asSinglePattern: Extractor = copy(fixed = List(typeOfSinglePattern)) + def productArity = fixed.length def hasSeq = repeated.exists def elementType = repeated.elementType diff --git a/src/compiler/scala/tools/nsc/transform/patmat/ScalacPatternExpanders.scala b/src/compiler/scala/tools/nsc/transform/patmat/ScalacPatternExpanders.scala index b1783dc81f..55d4366a46 100644 --- a/src/compiler/scala/tools/nsc/transform/patmat/ScalacPatternExpanders.scala +++ b/src/compiler/scala/tools/nsc/transform/patmat/ScalacPatternExpanders.scala @@ -43,8 +43,9 @@ trait ScalacPatternExpanders { orElse definitions.elementType(ArrayClass, seq) ) } - def newExtractor(whole: Type, fixed: List[Type], repeated: Repeated): Extractor = - logResult(s"newExtractor($whole, $fixed, $repeated")(Extractor(whole, fixed, repeated)) + def newExtractor(whole: Type, fixed: List[Type], repeated: Repeated, typeOfSinglePattern: Type): Extractor = + logResult(s"newExtractor($whole, $fixed, $repeated, $typeOfSinglePattern")(Extractor(whole, fixed, repeated, typeOfSinglePattern)) + def newExtractor(whole: Type, fixed: List[Type], repeated: Repeated): Extractor = newExtractor(whole, fixed, repeated, tupleType(fixed)) // Turn Seq[A] into Repeated(Seq[A], A, A*) def repeatedFromSeq(seqType: Type): Repeated = { @@ -74,16 +75,17 @@ trait ScalacPatternExpanders { * it was unapplySeq, so we have to funnel that information in separately. */ def unapplyMethodTypes(whole: Type, result: Type, isSeq: Boolean): Extractor = { - val expanded = ( - if (result =:= BooleanTpe) Nil - else typeOfMemberNamedGet(result) match { + if (result =:= BooleanTpe) newExtractor(whole, Nil, NoRepeated) + else { + val getResult = typeOfMemberNamedGet(result) + val expanded = getResult match { case rawGet if !hasSelectors(rawGet) => rawGet :: Nil case rawGet => typesOfSelectors(rawGet) } - ) - expanded match { - case init :+ last if isSeq => newExtractor(whole, init, repeatedFromSeq(last)) - case tps => newExtractor(whole, tps, NoRepeated) + expanded match { + case init :+ last if isSeq => newExtractor(whole, init, repeatedFromSeq(last), getResult) + case tps => newExtractor(whole, tps, NoRepeated, getResult) + } } } } @@ -142,12 +144,14 @@ trait ScalacPatternExpanders { def acceptMessage = if (extractor.isErroneous) "" else s" to hold ${extractor.offeringString}" val requiresTupling = isUnapply && patterns.totalArity == 1 && productArity > 1 - if (requiresTupling && effectivePatternArity(args) == 1) { - val sym = sel.symbol.owner - currentRun.reporting.deprecationWarning(sel.pos, sym, s"${sym} expects $productArity patterns$acceptMessage but crushing into $productArity-tuple to fit single pattern (SI-6675)") - } - - val normalizedExtractor = if (requiresTupling) tupleExtractor(extractor) else extractor + val normalizedExtractor = if (requiresTupling) { + val tupled = extractor.asSinglePattern + if (effectivePatternArity(args) == 1 && isTupleType(extractor.typeOfSinglePattern)) { + val sym = sel.symbol.owner + currentRun.reporting.deprecationWarning(sel.pos, sym, s"${sym} expects $productArity patterns$acceptMessage but crushing into $productArity-tuple to fit single pattern (SI-6675)") + } + tupled + } else extractor validateAligned(context, fn, Aligned(patterns, normalizedExtractor)) } |