diff options
Diffstat (limited to 'src/compiler/scala/tools/nsc/transform/patmat/ScalacPatternExpanders.scala')
-rw-r--r-- | src/compiler/scala/tools/nsc/transform/patmat/ScalacPatternExpanders.scala | 50 |
1 files changed, 27 insertions, 23 deletions
diff --git a/src/compiler/scala/tools/nsc/transform/patmat/ScalacPatternExpanders.scala b/src/compiler/scala/tools/nsc/transform/patmat/ScalacPatternExpanders.scala index b1783dc81f..d4f44303bb 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 = { @@ -73,26 +74,27 @@ trait ScalacPatternExpanders { * Unfortunately the MethodType does not carry the information of whether * 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 { + def unapplyMethodTypes(context: Context, whole: Type, result: Type, isSeq: Boolean): Extractor = { + if (result =:= BooleanTpe) newExtractor(whole, Nil, NoRepeated) + else { + val getResult = typeOfMemberNamedGet(result) + def noGetError() = { + val name = "unapply" + (if (isSeq) "Seq" else "") + context.error(context.tree.pos, s"The result type of an $name method must contain a member `get` to be used as an extractor pattern, no such member exists in ${result}") + } + val expanded = getResult match { + case global.NoType => noGetError(); Nil 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) + } } } } object alignPatterns extends ScalacPatternExpander { - /** Converts a T => (A, B, C) extractor to a T => ((A, B, CC)) extractor. - */ - def tupleExtractor(extractor: Extractor): Extractor = - extractor.copy(fixed = tupleType(extractor.fixed) :: Nil) - private def validateAligned(context: Context, tree: Tree, aligned: Aligned): Aligned = { import aligned._ @@ -129,8 +131,8 @@ trait ScalacPatternExpanders { val isUnapply = sel.symbol.name == nme.unapply val extractor = sel.symbol.name match { - case nme.unapply => unapplyMethodTypes(firstParamType(fn.tpe), sel.tpe, isSeq = false) - case nme.unapplySeq => unapplyMethodTypes(firstParamType(fn.tpe), sel.tpe, isSeq = true) + case nme.unapply => unapplyMethodTypes(context, firstParamType(fn.tpe), sel.tpe, isSeq = false) + case nme.unapplySeq => unapplyMethodTypes(context, firstParamType(fn.tpe), sel.tpe, isSeq = true) case _ => applyMethodTypes(fn.tpe) } @@ -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)) } |