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| author | Dmitry Petrashko <dmitry.petrashko@gmail.com> | 2014-10-13 15:05:47 +0200 |
|---|---|---|
| committer | Dmitry Petrashko <dmitry.petrashko@gmail.com> | 2014-10-13 15:07:37 +0200 |
| commit | 8b7988358782a569f9e74d83e98a2239d2085d40 (patch) | |
| tree | 5f2bc400e408f5f785539627abdb55fe51d842be /src/dotty/tools/dotc/transform/PatternMatcher.scala | |
| parent | ac583c50d6c26dcfc2eb7ad54f63f1de22f29ae7 (diff) | |
| download | dotty-8b7988358782a569f9e74d83e98a2239d2085d40.tar.gz dotty-8b7988358782a569f9e74d83e98a2239d2085d40.tar.bz2 dotty-8b7988358782a569f9e74d83e98a2239d2085d40.zip | |
EqualityTestTreeMaker: fix incorrect type of symbol
given a pattern
object b
x match {
case y @ b => <body>
}
y inside the <body> `y` should have type b.type.
Inherited from scalac EqualityTestTreeMaker would reset type of it
in order to achive this.
Dotty instead needs to know this in advance.
Diffstat (limited to 'src/dotty/tools/dotc/transform/PatternMatcher.scala')
| -rw-r--r-- | src/dotty/tools/dotc/transform/PatternMatcher.scala | 40 |
1 files changed, 31 insertions, 9 deletions
diff --git a/src/dotty/tools/dotc/transform/PatternMatcher.scala b/src/dotty/tools/dotc/transform/PatternMatcher.scala index 5a7d7c8a6..f3fca47d0 100644 --- a/src/dotty/tools/dotc/transform/PatternMatcher.scala +++ b/src/dotty/tools/dotc/transform/PatternMatcher.scala @@ -287,7 +287,10 @@ class PatternMatcher extends MiniPhaseTransform with DenotTransformer {thisTrans ) } else { assert(defn.isProductSubType(prev.tpe)) - Substitution(b, ref(prevSym))(next) + Block( + List(ValDef(prevSym, prev)), + Substitution(b, ref(prevSym))(next) + ) } } @@ -432,8 +435,10 @@ class PatternMatcher extends MiniPhaseTransform with DenotTransformer {thisTrans val cond: Tree val res: Tree - lazy val nextBinder = freshSym(pos, nextBinderTp) - lazy val localSubstitution = Substitution(List(prevBinder), List(ref(nextBinder))) + val nextBinder: Symbol + lazy val localSubstitution = + if(nextBinder ne prevBinder) Substitution(List(prevBinder), List(ref(nextBinder))) + else EmptySubstitution def chainBefore(next: Tree)(casegen: Casegen): Tree = /*atPos(pos)(*/casegen.flatMapCond(cond, res, nextBinder, substitution(next))//) @@ -728,7 +733,7 @@ class PatternMatcher extends MiniPhaseTransform with DenotTransformer {thisTrans val prevBinder = testedBinder - override lazy val nextBinder = afterTest.asTerm + val nextBinder = afterTest.asTerm def needsOuterTest(patType: Type, selType: Type, currentOwner: Symbol) = { // See the test for SI-7214 for motivation for dealias. Later `treeCondStrategy#outerTest` @@ -823,13 +828,14 @@ class PatternMatcher extends MiniPhaseTransform with DenotTransformer {thisTrans } // need to substitute to deal with existential types -- TODO: deal with existentials better, don't substitute (see RichClass during quick.comp) - case class EqualityTestTreeMaker(prevBinder: Symbol, patTree: Tree, override val pos: Position) extends CondTreeMaker { - val nextBinderTp = prevBinder.info.widen + case class EqualityTestTreeMaker(prevBinder: Symbol, subpatBinder: Symbol, patTree: Tree, override val pos: Position) extends CondTreeMaker { + val nextBinderTp = patTree.tpe & prevBinder.info + val nextBinder = if (prevBinder eq subpatBinder) freshSym(pos, nextBinderTp) else subpatBinder // NOTE: generate `patTree == patBinder`, since the extractor must be in control of the equals method (also, patBinder may be null) // equals need not be well-behaved, so don't intersect with pattern's (stabilized) type (unlike MaybeBoundTyped's accumType, where it's required) val cond = codegen._equals(patTree, prevBinder) - val res = ref(prevBinder) + val res = ref(prevBinder).ensureConforms(nextBinderTp) override def toString = "ET"+((prevBinder.name, patTree)) } @@ -1020,6 +1026,13 @@ class PatternMatcher extends MiniPhaseTransform with DenotTransformer {thisTrans } } + object SymbolAndValueBound { + def unapply(tree: Tree): Option[(Symbol, Tree)] = tree match { + case SymbolBound(sym, ConstantPattern(const)) => Some(sym -> const) + case _ => None + } + } + object TypeBound { def unapply(tree: Tree): Option[Type] = tree match { case Typed(_, _) => Some(tree.typeOpt) @@ -1027,11 +1040,19 @@ class PatternMatcher extends MiniPhaseTransform with DenotTransformer {thisTrans } } + object ConstantPattern { + def unapply(tree: Tree): Option[Tree] = tree match { + case Literal(Constant(_)) | Ident(_) | Select(_, _) | This(_) => Some(tree) + case _ => None + } + } + private def rebindTo(pattern: Tree) = BoundTree(binder, pattern) private def step(treeMakers: TreeMaker*)(subpatterns: BoundTree*): TranslationStep = TranslationStep(treeMakers.toList, subpatterns.toList) private def bindingStep(sub: Symbol, subpattern: Tree) = step(SubstOnlyTreeMaker(sub, binder))(rebindTo(subpattern)) - private def equalityTestStep() = step(EqualityTestTreeMaker(binder, tree, pos))() + private def equalityTestStep(testedSymbol: Symbol, constantSymbol: Symbol, constant: Tree) + = step(EqualityTestTreeMaker(testedSymbol, constantSymbol, constant, pos))() private def typeTestStep(sub: Symbol, subPt: Type) = step(TypeTestTreeMaker(sub, binder, subPt, sub.termRef)(pos))() private def alternativesStep(alts: List[Tree]) = step(AlternativesTreeMaker(binder, translatedAlts(alts), alts.head.pos))() private def translatedAlts(alts: List[Tree]) = alts map (alt => rebindTo(alt).translate()) @@ -1083,9 +1104,10 @@ class PatternMatcher extends MiniPhaseTransform with DenotTransformer {thisTrans case _: UnApply | _: Apply| Typed(_: UnApply | _: Apply, _) => extractorStep() case SymbolAndTypeBound(sym, tpe) => typeTestStep(sym, tpe) case TypeBound(tpe) => typeTestStep(binder, tpe) + case SymbolAndValueBound(sym, const) => equalityTestStep(binder, sym, const) case SymbolBound(sym, expr) => bindingStep(sym, expr) case WildcardPattern() => noStep() - case Literal(Constant(_)) | Ident(_) | Select(_, _) | This(_) => equalityTestStep() + case ConstantPattern(const) => equalityTestStep(binder, binder, const) case Alternative(alts) => alternativesStep(alts) case _ => ctx.error(unsupportedPatternMsg, pos) ; noStep() } |