From 21814b53e963d0e762efb808a664dd2c8b6e67a1 Mon Sep 17 00:00:00 2001 From: Adriaan Moors Date: Mon, 11 Jun 2012 17:57:12 +0200 Subject: minor cleanup in patmat and typers patmat: - remove Var's unused 'checked' member; subsumed by 'domain' - updated docs: no longer using isSuccess in __match typers: clean up indentation, swap ifs to failure-first --- .../tools/nsc/typechecker/PatternMatching.scala | 36 ++++---- .../scala/tools/nsc/typechecker/Typers.scala | 102 ++++++++++----------- 2 files changed, 67 insertions(+), 71 deletions(-) (limited to 'src/compiler') diff --git a/src/compiler/scala/tools/nsc/typechecker/PatternMatching.scala b/src/compiler/scala/tools/nsc/typechecker/PatternMatching.scala index f99d0e733b..7bac0dac3a 100644 --- a/src/compiler/scala/tools/nsc/typechecker/PatternMatching.scala +++ b/src/compiler/scala/tools/nsc/typechecker/PatternMatching.scala @@ -123,7 +123,6 @@ trait PatternMatching extends Transform with TypingTransformers with ast.TreeDSL def zero: M[Nothing] def one[T](x: P[T]): M[T] def guard[T](cond: P[Boolean], then: => P[T]): M[T] - def isSuccess[T, U](x: P[T])(f: P[T] => M[U]): P[Boolean] // used for isDefinedAt } * P and M are derived from one's signature (`def one[T](x: P[T]): M[T]`) @@ -137,7 +136,6 @@ trait PatternMatching extends Transform with TypingTransformers with ast.TreeDSL // NOTE: guard's return type must be of the shape M[T], where M is the monad in which the pattern match should be interpreted def guard[T](cond: Boolean, then: => T): Option[T] = if(cond) Some(then) else None def runOrElse[T, U](x: T)(f: T => Option[U]): U = f(x) getOrElse (throw new MatchError(x)) - def isSuccess[T, U](x: T)(f: T => Option[U]): Boolean = !f(x).isEmpty } */ @@ -2006,7 +2004,7 @@ trait PatternMatching extends Transform with TypingTransformers with ast.TreeDSL private val uniques = new collection.mutable.HashMap[Tree, Var] def apply(x: Tree): Var = uniques getOrElseUpdate(x, new Var(x, x.tpe)) } - class Var(val path: Tree, fullTp: Type, checked: Boolean = true) extends AbsVar { + class Var(val path: Tree, fullTp: Type) extends AbsVar { private[this] val id: Int = Var.nextId // private[this] var canModify: Option[Array[StackTraceElement]] = None @@ -2028,26 +2026,24 @@ trait PatternMatching extends Transform with TypingTransformers with ast.TreeDSL // we enumerate the subtypes of the full type, as that allows us to filter out more types statically, // once we go to run-time checks (on Const's), convert them to checkable types // TODO: there seems to be bug for singleton domains (variable does not show up in model) - lazy val domain: Option[Set[Const]] = - if (!checked) None - else { - val subConsts = enumerateSubtypes(fullTp).map{ tps => - tps.toSet[Type].map{ tp => - val domainC = TypeConst(tp) - registerEquality(domainC) - domainC - } + lazy val domain: Option[Set[Const]] = { + val subConsts = enumerateSubtypes(fullTp).map{ tps => + tps.toSet[Type].map{ tp => + val domainC = TypeConst(tp) + registerEquality(domainC) + domainC } + } - val allConsts = - if (! _considerNull) subConsts - else { - registerEquality(NullConst) - subConsts map (_ + NullConst) - } + val allConsts = + if (! _considerNull) subConsts + else { + registerEquality(NullConst) + subConsts map (_ + NullConst) + } - observed; allConsts - } + observed; allConsts + } // accessing after calling considerNull will result in inconsistencies lazy val domainSyms: Option[Set[Sym]] = domain map { _ map symForEqualsTo } diff --git a/src/compiler/scala/tools/nsc/typechecker/Typers.scala b/src/compiler/scala/tools/nsc/typechecker/Typers.scala index acf1b3dc59..18726d3c86 100644 --- a/src/compiler/scala/tools/nsc/typechecker/Typers.scala +++ b/src/compiler/scala/tools/nsc/typechecker/Typers.scala @@ -3103,66 +3103,67 @@ trait Typers extends Modes with Adaptations with Tags { val otpe = fun.tpe - if (args.length > MaxTupleArity) - return duplErrorTree(TooManyArgsPatternError(fun)) - - // - def freshArgType(tp: Type): (List[Symbol], Type) = tp match { - case MethodType(param :: _, _) => - (Nil, param.tpe) - case PolyType(tparams, restpe) => - createFromClonedSymbols(tparams, freshArgType(restpe)._2)((ps, t) => ((ps, t))) - // No longer used, see test case neg/t960.scala (#960 has nothing to do with it) - case OverloadedType(_, _) => - OverloadedUnapplyError(fun) - (Nil, ErrorType) - case _ => - UnapplyWithSingleArgError(fun) - (Nil, ErrorType) - } + if (args.length > MaxTupleArity) + return duplErrorTree(TooManyArgsPatternError(fun)) + + // + def freshArgType(tp: Type): (List[Symbol], Type) = tp match { + case MethodType(param :: _, _) => + (Nil, param.tpe) + case PolyType(tparams, restpe) => + createFromClonedSymbols(tparams, freshArgType(restpe)._2)((ps, t) => ((ps, t))) + // No longer used, see test case neg/t960.scala (#960 has nothing to do with it) + case OverloadedType(_, _) => + OverloadedUnapplyError(fun) + (Nil, ErrorType) + case _ => + UnapplyWithSingleArgError(fun) + (Nil, ErrorType) + } - val unapp = unapplyMember(otpe) - val unappType = otpe.memberType(unapp) - val argDummy = context.owner.newValue(nme.SELECTOR_DUMMY, fun.pos, SYNTHETIC) setInfo pt - val arg = Ident(argDummy) setType pt + val unapp = unapplyMember(otpe) + val unappType = otpe.memberType(unapp) + val argDummy = context.owner.newValue(nme.SELECTOR_DUMMY, fun.pos, SYNTHETIC) setInfo pt + val arg = Ident(argDummy) setType pt val uncheckedTypeExtractor = if (unappType.paramTypes.nonEmpty) extractorForUncheckedType(tree.pos, unappType.paramTypes.head) else None - if (!isApplicableSafe(Nil, unappType, List(pt), WildcardType)) { - //Console.println("UNAPP: need to typetest, arg.tpe = "+arg.tpe+", unappType = "+unappType) - val (freeVars, unappFormal) = freshArgType(unappType.skolemizeExistential(context.owner, tree)) - val unapplyContext = context.makeNewScope(context.tree, context.owner) - freeVars foreach unapplyContext.scope.enter + if (!isApplicableSafe(Nil, unappType, List(pt), WildcardType)) { + //Console.println("UNAPP: need to typetest, arg.tpe = "+arg.tpe+", unappType = "+unappType) + val (freeVars, unappFormal) = freshArgType(unappType.skolemizeExistential(context.owner, tree)) + val unapplyContext = context.makeNewScope(context.tree, context.owner) + freeVars foreach unapplyContext.scope.enter - val typer1 = newTyper(unapplyContext) + val typer1 = newTyper(unapplyContext) val pattp = typer1.infer.inferTypedPattern(tree, unappFormal, arg.tpe, canRemedy = uncheckedTypeExtractor.nonEmpty) - // turn any unresolved type variables in freevars into existential skolems - val skolems = freeVars map (fv => unapplyContext.owner.newExistentialSkolem(fv, fv)) - arg.tpe = pattp.substSym(freeVars, skolems) - argDummy setInfo arg.tpe - } + // turn any unresolved type variables in freevars into existential skolems + val skolems = freeVars map (fv => unapplyContext.owner.newExistentialSkolem(fv, fv)) + arg.tpe = pattp.substSym(freeVars, skolems) + argDummy setInfo arg.tpe + } - // setType null is necessary so that ref will be stabilized; see bug 881 - val fun1 = typedPos(fun.pos)(Apply(Select(fun setType null, unapp), List(arg))) + // setType null is necessary so that ref will be stabilized; see bug 881 + val fun1 = typedPos(fun.pos)(Apply(Select(fun setType null, unapp), List(arg))) - if (fun1.tpe.isErroneous) { - duplErrTree - } else { - val formals0 = unapplyTypeList(fun1.symbol, fun1.tpe) - val formals1 = formalTypes(formals0, args.length) - if (sameLength(formals1, args)) { - val args1 = typedArgs(args, mode, formals0, formals1) - // This used to be the following (failing) assert: - // assert(isFullyDefined(pt), tree+" ==> "+UnApply(fun1, args1)+", pt = "+pt) - // I modified as follows. See SI-1048. - val pt1 = if (isFullyDefined(pt)) pt else makeFullyDefined(pt) - - val itype = glb(List(pt1, arg.tpe)) - arg.tpe = pt1 // restore type (arg is a dummy tree, just needs to pass typechecking) + if (fun1.tpe.isErroneous) duplErrTree + else { + val formals0 = unapplyTypeList(fun1.symbol, fun1.tpe) + val formals1 = formalTypes(formals0, args.length) + + if (!sameLength(formals1, args)) duplErrorTree(WrongNumberArgsPatternError(tree, fun)) + else { + val args1 = typedArgs(args, mode, formals0, formals1) + // This used to be the following (failing) assert: + // assert(isFullyDefined(pt), tree+" ==> "+UnApply(fun1, args1)+", pt = "+pt) + // I modified as follows. See SI-1048. + val pt1 = if (isFullyDefined(pt)) pt else makeFullyDefined(pt) + + val itype = glb(List(pt1, arg.tpe)) + arg.tpe = pt1 // restore type (arg is a dummy tree, just needs to pass typechecking) val unapply = UnApply(fun1, args1) setPos tree.pos setType itype // if the type that the unapply method expects for its argument is uncheckable, wrap in classtag extractor @@ -3170,9 +3171,8 @@ trait Typers extends Modes with Adaptations with Tags { // also skip if we already wrapped a classtag extractor (so we don't keep doing that forever) if (uncheckedTypeExtractor.isEmpty || fun1.symbol.owner.isNonBottomSubClass(ClassTagClass)) unapply else wrapClassTagUnapply(unapply, uncheckedTypeExtractor.get, unappType.paramTypes.head) - } else - duplErrorTree(WrongNumberArgsPatternError(tree, fun)) - } + } + } } def wrapClassTagUnapply(uncheckedPattern: Tree, classTagExtractor: Tree, pt: Type): Tree = { -- cgit v1.2.3