Fix/#34 pathresolvers

src/dotty/tools/dotc/ast/CheckTrees.scala

@@ -135,7 +135,7 @@ object CheckTrees {
       check(finalizer.isTerm)
       check(handler.isTerm)
       check(handler.tpe derivesFrom defn.FunctionClass(1))
-      check(handler.tpe.baseTypeArgs(defn.FunctionClass(1)).head <:< defn.ThrowableType)
+      check(handler.tpe.baseArgInfos(defn.FunctionClass(1)).head <:< defn.ThrowableType)
     case Throw(expr) =>
       check(expr.isValue)
       check(expr.tpe.derivesFrom(defn.ThrowableClass))
@@ -210,9 +210,9 @@ object CheckTrees {
             check(args.isEmpty)
           else {
             check(rtp isRef defn.OptionClass)
-            val normArgs = rtp.typeArgs match {
+            val normArgs = rtp.argTypesHi match {
               case optionArg :: Nil =>
-                optionArg.typeArgs match {
+                optionArg.argTypesHi match {
                   case Nil =>
                     optionArg :: Nil
                   case tupleArgs if defn.isTupleType(optionArg) =>

src/dotty/tools/dotc/ast/tpd.scala

@@ -336,7 +336,7 @@ object tpd extends Trees.Instance[Type] with TypedTreeInfo {
 
   /** new C(args) */
   def New(tp: Type, args: List[Tree])(implicit ctx: Context): Apply = {
-    val targs = tp.typeArgs
+    val targs = tp.argTypes
     Apply(
       Select(
         New(tp withoutArgs targs),

src/dotty/tools/dotc/ast/untpd.scala

@@ -124,7 +124,7 @@ object untpd extends Trees.Instance[Untyped] with TreeInfo[Untyped] {
       case TypedSplice(AppliedTypeTree(tycon, targs)) =>
         (TypedSplice(tycon), targs map TypedSplice)
       case TypedSplice(tpt1: Tree) =>
-        val argTypes = tpt1.tpe.typeArgs
+        val argTypes = tpt1.tpe.argTypes
         val tycon = tpt1.tpe.withoutArgs(argTypes)
         def wrap(tpe: Type) = TypeTree(tpe) withPos tpt.pos
         (wrap(tycon), argTypes map wrap)

src/dotty/tools/dotc/core/Definitions.scala

@@ -286,7 +286,7 @@ class Definitions {
     def unapply(ft: Type): Option[(List[Type], Type)] = { // Dotty deviation: Type annotation needed because inferred type
                                                           // is Some[(List[Type], Type)] | None, which is not a legal unapply type.
       val tsym = ft.typeSymbol
-      lazy val targs = ft.typeArgs
+      lazy val targs = ft.argInfos
       if ((FunctionClasses contains tsym) &&
           (targs.length - 1 <= MaxFunctionArity) &&
           (FunctionClass(targs.length - 1) == tsym)) Some((targs.init, targs.last)) // Dotty deviation: no auto-tupling
@@ -317,7 +317,7 @@ class Definitions {
   lazy val RootImports = List[Symbol](JavaLangPackageVal, ScalaPackageVal, ScalaPredefModule, DottyPredefModule)
 
   def isTupleType(tp: Type) = {
-    val arity = tp.dealias.typeArgs.length
+    val arity = tp.dealias.argInfos.length
     arity <= MaxTupleArity && (tp isRef TupleClass(arity))
   }
 
@@ -329,7 +329,7 @@ class Definitions {
     0 <= arity && arity <= MaxFunctionArity && (tp isRef FunctionClass(arity))
   }
 
-  def functionArity(tp: Type) = tp.dealias.typeArgs.length - 1
+  def functionArity(tp: Type) = tp.dealias.argInfos.length - 1
 
   // ----- Higher kinds machinery ------------------------------------------
 

src/dotty/tools/dotc/core/TypeApplications.scala

@@ -12,6 +12,29 @@ import Flags._
 import util.Positions.Position
 import collection.mutable
 
+object TypeApplications {
+
+  /** Assert type is not a TypeBounds instance and return it unchanged */
+  val noBounds = (tp: Type) => tp match {
+    case tp: TypeBounds => throw new AssertionError("no TypeBounds allowed")
+    case _ => tp
+  }
+
+  /** If `tp` is a TypeBounds instance return its lower bound else return `tp` */
+  val boundsToLo = (tp: Type) => tp match {
+    case tp: TypeBounds => tp.lo
+    case _ => tp
+  }
+
+  /** If `tp` is a TypeBounds instance return its upper bound else return `tp` */
+  val boundsToHi = (tp: Type) => tp match {
+    case tp: TypeBounds => tp.hi
+    case _ => tp
+  }
+}
+
+import TypeApplications._
+
 /** A decorator that provides methods for modeling type application */
 class TypeApplications(val self: Type) extends AnyVal {
 
@@ -135,24 +158,43 @@ class TypeApplications(val self: Type) extends AnyVal {
       else TypeAlias(self, v)
   }
 
-  /** The type arguments of the base type instance wrt `base` of this type */
-  final def baseTypeArgs(base: Symbol)(implicit ctx: Context): List[Type] =
+  /** The type arguments of this type's base type instance wrt.`base`.
+   *  Existential types in arguments are returned as TypeBounds instances.
+   */
+  final def baseArgInfos(base: Symbol)(implicit ctx: Context): List[Type] =
     if (self derivesFrom base)
-      base.typeParams map (param => self.member(param.name).info.argType(param))
+      base.typeParams map (param => self.member(param.name).info.argInfo(param))
     else
       Nil
 
+  /** The type arguments of this type's base type instance wrt.`base`.
+   *  Existential types in arguments are disallowed.
+   */
+  final def baseArgTypes(base: Symbol)(implicit ctx: Context): List[Type] = baseArgInfos(base) mapConserve noBounds
+
+  /** The type arguments of this type's base type instance wrt.`base`.
+   *  Existential types in arguments are approximanted by their lower bound.
+   */
+  final def baseArgTypesLo(base: Symbol)(implicit ctx: Context): List[Type] = baseArgInfos(base) mapConserve boundsToLo
+
+  /** The type arguments of this type's base type instance wrt.`base`.
+   *  Existential types in arguments are approximanted by their upper bound.
+   */
+  final def baseArgTypesHi(base: Symbol)(implicit ctx: Context): List[Type] = baseArgInfos(base) mapConserve boundsToHi
+
   /** The first type argument of the base type instance wrt `base` of this type */
-  final def firstBaseTypeArg(base: Symbol)(implicit ctx: Context): Type = base.typeParams match {
+  final def firstBaseArgInfo(base: Symbol)(implicit ctx: Context): Type = base.typeParams match {
     case param :: _ if self derivesFrom base =>
-      self.member(param.name).info.argType(param)
+      self.member(param.name).info.argInfo(param)
     case _ =>
       NoType
   }
 
-  /** The base type including all type arguments of this type */
+  /** The base type including all type arguments of this type.
+   *  Existential types in arguments are returned as TypeBounds instances.
+   */
   final def baseTypeWithArgs(base: Symbol)(implicit ctx: Context): Type =
-    self.baseTypeRef(base).appliedTo(baseTypeArgs(base))
+    self.baseTypeRef(base).appliedTo(baseArgInfos(base))
 
   /** Translate a type of the form From[T] to To[T], keep other types as they are.
    *  `from` and `to` must be static classes, both with one type parameter, and the same variance.
@@ -163,9 +205,10 @@ class TypeApplications(val self: Type) extends AnyVal {
     else self
 
   /** If this is an encoding of a (partially) applied type, return its arguments,
-   *  otherwise return Nil
+   *  otherwise return Nil. 
+   *  Existential types in arguments are returned as TypeBounds instances.
    */
-  final def typeArgs(implicit ctx: Context): List[Type] = {
+  final def argInfos(implicit ctx: Context): List[Type] = {
     var tparams: List[TypeSymbol] = null
     def recur(tp: Type, refineCount: Int): mutable.ListBuffer[Type] = tp.stripTypeVar match {
       case tp @ RefinedType(tycon, name) =>
@@ -175,7 +218,7 @@ class TypeApplications(val self: Type) extends AnyVal {
           if (tparams == null) tparams = tycon.typeParams
           if (buf.size < tparams.length) {
             val tparam = tparams(buf.size)
-            if (name == tparam.name) buf += tp.refinedInfo.argType(tparam)
+            if (name == tparam.name) buf += tp.refinedInfo.argInfo(tparam)
             else null
           } else null
         }
@@ -187,6 +230,15 @@ class TypeApplications(val self: Type) extends AnyVal {
     if (buf == null) Nil else buf.toList
   }
 
+  /** Argument types where existential types in arguments are disallowed */
+  def argTypes(implicit ctx: Context) = argInfos mapConserve noBounds
+
+  /** Argument types where existential types in arguments are approximated by their lower bound */
+  def argTypesLo(implicit ctx: Context) = argInfos mapConserve boundsToLo
+
+  /** Argument types where existential types in arguments are approximated by their upper bound  */
+  def argTypesHi(implicit ctx: Context) = argInfos mapConserve boundsToHi
+
   /** The core type without any type arguments.
    *  @param `typeArgs` must be the type arguments of this type.
    */
@@ -201,7 +253,7 @@ class TypeApplications(val self: Type) extends AnyVal {
   /** If this is the image of a type argument to type parameter `tparam`,
    *  recover the type argument, otherwise NoType.
    */
-  final def argType(tparam: Symbol)(implicit ctx: Context): Type = self match {
+  final def argInfo(tparam: Symbol)(implicit ctx: Context): Type = self match {
     case TypeBounds(lo, hi) =>
       if (lo eq hi) hi
       else {
@@ -216,7 +268,7 @@ class TypeApplications(val self: Type) extends AnyVal {
 
   /** The element type of a sequence or array */
   def elemType(implicit ctx: Context): Type =
-    firstBaseTypeArg(defn.SeqClass) orElse firstBaseTypeArg(defn.ArrayClass)
+    firstBaseArgInfo(defn.SeqClass) orElse firstBaseArgInfo(defn.ArrayClass)
 
   /** If this type is of the normalized form Array[...[Array[T]...]
    *  return the number of Array wrappers and T.
@@ -225,7 +277,7 @@ class TypeApplications(val self: Type) extends AnyVal {
   final def splitArray(implicit ctx: Context): (Int, Type) = {
     def recur(n: Int, tp: Type): (Int, Type) = tp.stripTypeVar match {
       case RefinedType(tycon, _) if tycon isRef defn.ArrayClass =>
-        tp.typeArgs match {
+        tp.argInfos match {
           case arg :: Nil => recur(n + 1, arg)
           case _ => (n, tp)
         }
@@ -274,7 +326,7 @@ class TypeApplications(val self: Type) extends AnyVal {
 
       val correspondingParamName: Map[Symbol, TypeName] = {
         for {
-          (tparam, targ: TypeRef) <- cls.typeParams zip typeArgs
+          (tparam, targ: TypeRef) <- cls.typeParams zip argInfos
           if boundSyms contains targ.symbol
         } yield targ.symbol -> tparam.name
       }.toMap

src/dotty/tools/dotc/core/TypeComparer.scala

@@ -616,7 +616,7 @@ class TypeComparer(initctx: Context) extends DotClass {
    */
   def isSubTypeHK(tp1: Type, tp2: Type): Boolean = {
     val tparams = tp1.typeParams
-    val hkArgs = tp2.typeArgs
+    val hkArgs = tp2.argInfos
     (hkArgs.length == tparams.length) && {
       val base = tp1.narrow
       (tparams, hkArgs).zipped.forall { (tparam, hkArg) =>
@@ -752,7 +752,7 @@ class TypeComparer(initctx: Context) extends DotClass {
   /** The least upper bound of two types
    *  @note  We do not admit singleton types in or-types as lubs.
    */
-  def lub(tp1: Type, tp2: Type): Type =
+  def lub(tp1: Type, tp2: Type): Type = /*>|>*/ ctx.traceIndented(s"lub(${tp1.show}, ${tp2.show})", typr, show = true) /*<|<*/ {
     if (tp1 eq tp2) tp1
     else if (!tp1.exists) tp1
     else if (!tp2.exists) tp2
@@ -772,6 +772,7 @@ class TypeComparer(initctx: Context) extends DotClass {
         }
       }
     }
+  }
 
   /** The least upper bound of a list of types */
   final def lub(tps: List[Type]): Type =

src/dotty/tools/dotc/core/Types.scala

@@ -96,7 +96,7 @@ object Types {
         else thissym eq sym
       case this1: RefinedType =>
         // make sure all refinements are type arguments
-        this1.parent.isRef(sym) && this.typeArgs.nonEmpty
+        this1.parent.isRef(sym) && this.argInfos.nonEmpty
       case _ =>
         false
     }

src/dotty/tools/dotc/core/pickling/UnPickler.scala

@@ -76,7 +76,7 @@ object UnPickler {
     case tp @ MethodType(paramNames, paramTypes) =>
       val lastArg = paramTypes.last
       assert(lastArg isRef defn.ArrayClass)
-      val elemtp0 :: Nil = lastArg.baseTypeArgs(defn.ArrayClass)
+      val elemtp0 :: Nil = lastArg.baseArgInfos(defn.ArrayClass)
       val elemtp = elemtp0 match {
         case AndType(t1, t2) if t1.typeSymbol.isAbstractType && (t2 isRef defn.ObjectClass) =>
           t1 // drop intersection with Object for abstract types in varargs. UnCurry can handle them.

src/dotty/tools/dotc/printing/RefinedPrinter.scala

@@ -96,7 +96,7 @@ class RefinedPrinter(_ctx: Context) extends PlainPrinter(_ctx) {
       }
     tp match {
       case tp: RefinedType =>
-        val args = tp.typeArgs
+        val args = tp.argInfos
         if (args.nonEmpty) {
           val tycon = tp.unrefine
           val cls = tycon.typeSymbol

src/dotty/tools/dotc/typer/Applications.scala

@@ -24,6 +24,7 @@ import EtaExpansion._
 import collection.mutable
 import reflect.ClassTag
 import config.Printers._
+import TypeApplications._
 import language.implicitConversions
 
 object Applications {
@@ -266,7 +267,7 @@ trait Applications extends Compatibility { self: Typer =>
               case arg :: Nil if isVarArg(arg) =>
                 addTyped(arg, formal)
               case _ =>
-                val elemFormal = formal.typeArgs.head
+                val elemFormal = formal.argTypesLo.head
                 args foreach (addTyped(_, elemFormal))
                 makeVarArg(args.length, elemFormal)
             }
@@ -609,7 +610,7 @@ trait Applications extends Compatibility { self: Typer =>
       if (extractorMemberType(unapplyResult, nme.isDefined) isRef defn.BooleanClass) {
         if (getTp.exists)
           if (unapply.symbol.name == nme.unapplySeq) {
-            val seqArg = getTp.firstBaseTypeArg(defn.SeqClass)
+            val seqArg = boundsToHi(getTp.firstBaseArgInfo(defn.SeqClass))
             if (seqArg.exists) return args map Function.const(seqArg)
           }
           else return getSelectors(getTp)
@@ -683,6 +684,7 @@ trait Applications extends Compatibility { self: Typer =>
         }
 
         var argTypes = unapplyArgs(unapplyApp.tpe)
+        for (argType <- argTypes) assert(!argType.isInstanceOf[TypeBounds], unapplyApp.tpe.show)
         val bunchedArgs = argTypes match {
           case argType :: Nil if argType.isRepeatedParam => untpd.SeqLiteral(args) :: Nil
           case _ => args
@@ -770,7 +772,7 @@ trait Applications extends Compatibility { self: Typer =>
         val tparams = ctx.newTypeParams(alt1.symbol.owner, tp1.paramNames, EmptyFlags, bounds)
         isAsSpecific(alt1, tp1.instantiate(tparams map (_.typeRef)), alt2, tp2)
       case tp1: MethodType =>
-        def repeatedToSingle(tp: Type) = if (tp.isRepeatedParam) tp.typeArgs.head else tp
+        def repeatedToSingle(tp: Type) = if (tp.isRepeatedParam) tp.argTypesHi.head else tp
         isApplicable(alt2, tp1.paramTypes map repeatedToSingle, WildcardType) ||
         tp1.paramTypes.isEmpty && tp2.isInstanceOf[MethodOrPoly]
       case _ =>

src/dotty/tools/dotc/typer/Typer.scala

@@ -438,7 +438,7 @@ class Typer extends Namer with Applications with Implicits {
   }
 
   def typedPair(tree: untpd.Pair, pt: Type)(implicit ctx: Context) = track("typedPair") {
-    val (leftProto, rightProto) = pt.typeArgs match {
+    val (leftProto, rightProto) = pt.argTypesLo match {
       case l :: r :: Nil if pt isRef defn.PairClass => (l, r)
       case _ => (WildcardType, WildcardType)
     }
@@ -561,7 +561,7 @@ class Typer extends Namer with Applications with Implicits {
       val params = args.asInstanceOf[List[untpd.ValDef]]
       val (protoFormals, protoResult): (List[Type], Type) = pt match {
         case _ if defn.isFunctionType(pt) =>
-          (pt.dealias.typeArgs.init, pt.dealias.typeArgs.last)
+          (pt.dealias.argInfos.init, pt.dealias.argInfos.last)
         case SAMType(meth) =>
           val mt @ MethodType(_, paramTypes) = meth.info
           (paramTypes, mt.resultType)
@@ -750,7 +750,7 @@ class Typer extends Namer with Applications with Implicits {
     val expr1 = typed(tree.expr, pt)
     val handler1 = typed(tree.handler, defn.FunctionType(defn.ThrowableType :: Nil, pt))
     val finalizer1 = typed(tree.finalizer, defn.UnitType)
-    val handlerTypeArgs = handler1.tpe.baseTypeArgs(defn.FunctionClass(1))
+    val handlerTypeArgs = handler1.tpe.baseArgTypesHi(defn.FunctionClass(1))
     val ownType = if (handlerTypeArgs.nonEmpty) expr1.tpe | handlerTypeArgs(1) else expr1.tpe
     cpy.Try(tree, expr1, handler1, finalizer1) withType ownType
   }

test/dotc/tests.scala

@@ -71,5 +71,11 @@ class tests extends CompilerTest {
       "-Ylog:frontend",
       "-Xprompt"))
 
+  @Test def testIssue_34 = compileArgs(Array(
+      dotcDir + "tools/dotc/config/Properties.scala",
+      dotcDir + "tools/dotc/config/PathResolver.scala",
+      "-Ylog:frontend",
+      "-Xprompt"))
+
   //@Test def dotc_compilercommand = compileFile(dotcDir + "tools/dotc/config/", "CompilerCommand")
 }