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Scala example source code file (Definitions.scala)

This example Scala source code file (Definitions.scala) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" TM.

Java - Scala tags/keywords

boolean, final, final, int, list, list, name, nil, nosymbol, symbol, symbol, type, type, typeref

The Scala Definitions.scala source code

/* NSC -- new Scala compiler
 * Copyright 2005-2011 LAMP/EPFL
 * @author  Martin Odersky
 */

package scala.tools.nsc
package symtab

import scala.collection.{ mutable, immutable }
import scala.collection.mutable.{ HashMap }
import scala.tools.nsc.util.NoPosition
import Flags._
import PartialFunction._
import classfile.ClassfileConstants

trait Definitions extends reflect.generic.StandardDefinitions {
  self: SymbolTable =>
  
  // the scala value classes
  trait ValueClassDefinitions {
    self: definitions.type =>
    
    private[Definitions] def valueCache(name: Name) = {
      if (name.isTypeName) ScalaPackageClass.info member name
      else ScalaPackageClass.info member name suchThat (_ hasFlag MODULE)
    }
    private[Definitions] def valueModuleMethod(className: Name, methodName: Name): Symbol = {
      valueCache(className.toTermName).moduleClass.tpe member methodName
    }

    import ClassfileConstants._
    
    private val nameToWeight = Map[Name, Int](
      tpnme.Byte   -> 2,
      tpnme.Char   -> 3,
      tpnme.Short  -> 4,
      tpnme.Int    -> 12,
      tpnme.Long   -> 24,
      tpnme.Float  -> 48,
      tpnme.Double -> 96
    )

    private val nameToTag = Map[Name, Char](
      tpnme.Byte    -> BYTE_TAG,
      tpnme.Char    -> CHAR_TAG,
      tpnme.Short   -> SHORT_TAG,
      tpnme.Int     -> INT_TAG,
      tpnme.Long    -> LONG_TAG,
      tpnme.Float   -> FLOAT_TAG,
      tpnme.Double  -> DOUBLE_TAG,
      tpnme.Boolean -> BOOL_TAG,
      tpnme.Unit    -> VOID_TAG,
      tpnme.Object  -> TVAR_TAG
    )
    
    private def classesMap[T](f: Name => T) = symbolsMap(ScalaValueClassesNoUnit, f)
    private def symbolsMap[T](syms: List[Symbol], f: Name => T): Map[Symbol, T] = syms zip (syms map (x => f(x.name))) toMap
    private def symbolsMapFilt[T](syms: List[Symbol], p: Name => Boolean, f: Name => T) = symbolsMap(syms filter (x => p(x.name)), f)    
    
    private def boxedName(name: Name) = sn.Boxed(name.toTypeName)
    
    lazy val abbrvTag         = symbolsMap(ObjectClass :: ScalaValueClasses, nameToTag)
    lazy val numericWeight    = symbolsMapFilt(ScalaValueClasses, nameToWeight.keySet, nameToWeight)
    lazy val boxedModule      = classesMap(x => getModule(boxedName(x)))
    lazy val boxedClass       = classesMap(x => getClass(boxedName(x)))
    lazy val refClass         = classesMap(x => getClass("scala.runtime." + x + "Ref"))
    lazy val volatileRefClass = classesMap(x => getClass("scala.runtime.Volatile" + x + "Ref"))
    lazy val boxMethod        = classesMap(x => valueModuleMethod(x, nme.box))
    lazy val unboxMethod      = classesMap(x => valueModuleMethod(x, nme.unbox))

    private def newClass(owner: Symbol, name: TypeName, parents: List[Type]): Symbol = {
      val clazz = owner.newClass(NoPosition, name)
      clazz.setInfo(ClassInfoType(parents, new Scope, clazz))
      owner.info.decls.enter(clazz) 
      clazz
    }

    def isNumericSubClass(sub: Symbol, sup: Symbol) = {
      val cmp = for (w1 <- numericWeight get sub ; w2 <- numericWeight get sup) yield w2 % w1
      cmp exists (_ == 0)
    }

    /** Is symbol a numeric value class? */
    def isNumericValueClass(sym: Symbol): Boolean =
      numericWeight contains sym
    
    private[Definitions] def fullNameStrings: List[String] = nme.ScalaValueNames map ("scala." + _)
    private[Definitions] lazy val fullValueName: Set[Name] = {
      val values = nme.ScalaValueNames flatMap (x => List(newTypeName("scala." + x), newTermName("scala." + x)))
      values.toSet + newTypeName("scala.AnyVal")
    }

    lazy val AnyValClass  = valueCache(tpnme.AnyVal)
    lazy val UnitClass    = valueCache(tpnme.Unit)
    lazy val ByteClass    = valueCache(tpnme.Byte)
    lazy val ShortClass   = valueCache(tpnme.Short)
    lazy val CharClass    = valueCache(tpnme.Char)
    lazy val IntClass     = valueCache(tpnme.Int)
    lazy val LongClass    = valueCache(tpnme.Long)
    lazy val FloatClass   = valueCache(tpnme.Float)
    lazy val DoubleClass  = valueCache(tpnme.Double)
    lazy val BooleanClass = valueCache(tpnme.Boolean)
      def Boolean_and = getMember(BooleanClass, nme.ZAND)
      def Boolean_or  = getMember(BooleanClass, nme.ZOR)

    def ScalaValueClassesNoUnit = ScalaValueClasses filterNot (_ eq UnitClass)
    def ScalaValueClasses: List[Symbol] = List(
      UnitClass,
      BooleanClass,
      ByteClass, 
      ShortClass,
      CharClass,
      IntClass,
      LongClass,
      FloatClass,
      DoubleClass
    )
  }

  object definitions extends AbsDefinitions with ValueClassDefinitions {
    private var isInitialized = false
    def isDefinitionsInitialized = isInitialized

    // symbols related to packages
    var emptypackagescope: Scope = null //debug
    
    // This is the package _root_.  The actual root cannot be referenced at
    // the source level, but _root_ is essentially a function () => <root>.
    lazy val RootPackage: Symbol = {
      val rp = NoSymbol.newValue(NoPosition, nme.ROOTPKG)
        .setFlag(FINAL | MODULE | PACKAGE | JAVA)
        .setInfo(NullaryMethodType(RootClass.tpe))
      RootClass.sourceModule = rp
      rp
    }
    // This is the actual root of everything, including the package _root_.
    lazy val RootClass: ModuleClassSymbol = NoSymbol.newModuleClass(NoPosition, tpnme.ROOT)
          .setFlag(FINAL | MODULE | PACKAGE | JAVA).setInfo(rootLoader)

    // The empty package, which holds all top level types without given packages.
    lazy val EmptyPackage       = RootClass.newPackage(NoPosition, nme.EMPTY_PACKAGE_NAME).setFlag(FINAL)
    lazy val EmptyPackageClass  = EmptyPackage.moduleClass

    lazy val JavaLangPackage    = getModule(sn.JavaLang)
    lazy val ScalaPackage       = getModule("scala")
    lazy val ScalaPackageClass  = ScalaPackage.tpe.typeSymbol
    
    lazy val RuntimePackage       = getModule("scala.runtime")
    lazy val RuntimePackageClass  = RuntimePackage.tpe.typeSymbol

    // convenient one-argument parameter lists
    lazy val anyparam     = List(AnyClass.typeConstructor)
    lazy val anyvalparam  = List(AnyValClass.typeConstructor)
    lazy val anyrefparam  = List(AnyRefClass.typeConstructor)
    
    // private parameter conveniences
    private def booltype    = BooleanClass.typeConstructor
    private def boolparam   = List(booltype)
    private def bytetype    = ByteClass.typeConstructor
    private def byteparam   = List(bytetype)
    private def shorttype   = ShortClass.typeConstructor
    private def shortparam  = List(shorttype)
    private def inttype     = IntClass.typeConstructor
    private def intparam    = List(inttype)
    private def longtype    = LongClass.typeConstructor
    private def longparam   = List(longtype)
    private def floattype   = FloatClass.typeConstructor
    private def floatparam  = List(floattype)
    private def doubletype  = DoubleClass.typeConstructor
    private def doubleparam = List(doubletype)
    private def chartype    = CharClass.typeConstructor
    private def charparam   = List(chartype)
    private def stringtype  = StringClass.typeConstructor
    
    // top types
    lazy val AnyClass             = newClass(ScalaPackageClass, tpnme.Any, Nil) setFlag (ABSTRACT)
    lazy val AnyRefClass          = newAlias(ScalaPackageClass, tpnme.AnyRef, ObjectClass.typeConstructor)
    lazy val ObjectClass          = getClass(sn.Object)
    lazy val AnyCompanionClass    = getClass("scala.AnyCompanion") setFlag (SEALED | ABSTRACT | TRAIT)
    lazy val AnyValCompanionClass = getClass("scala.AnyValCompanion") setFlag (SEALED | ABSTRACT | TRAIT)

    // bottom types
    lazy val NullClass            = newClass(ScalaPackageClass, tpnme.Null, anyrefparam) setFlag (ABSTRACT | TRAIT | FINAL)
    lazy val NothingClass         = newClass(ScalaPackageClass, tpnme.Nothing, anyparam) setFlag (ABSTRACT | TRAIT | FINAL)
    lazy val RuntimeNothingClass  = getClass(ClassfileConstants.SCALA_NOTHING)
    lazy val RuntimeNullClass     = getClass(ClassfileConstants.SCALA_NULL)
    
    // exceptions and other throwables
    lazy val ClassCastExceptionClass        = getClass("java.lang.ClassCastException")
    lazy val IndexOutOfBoundsExceptionClass = getClass(sn.IOOBException)
    lazy val InvocationTargetExceptionClass = getClass(sn.InvTargetException)
    lazy val MatchErrorClass                = getClass("scala.MatchError")
    lazy val NonLocalReturnControlClass     = getClass("scala.runtime.NonLocalReturnControl")
    lazy val NullPointerExceptionClass      = getClass(sn.NPException)
    lazy val ThrowableClass                 = getClass(sn.Throwable)
    lazy val UninitializedErrorClass        = getClass("scala.UninitializedFieldError")
    
    // annotations
    lazy val AnnotationClass            = getClass("scala.annotation.Annotation")
    lazy val ClassfileAnnotationClass   = getClass("scala.annotation.ClassfileAnnotation")
    lazy val StaticAnnotationClass      = getClass("scala.annotation.StaticAnnotation")
    lazy val uncheckedStableClass       = getClass("scala.annotation.unchecked.uncheckedStable") 
    lazy val uncheckedVarianceClass     = getClass("scala.annotation.unchecked.uncheckedVariance")
    lazy val UncheckedClass             = getClass("scala.unchecked")
    lazy val ThrowsClass                = getClass("scala.throws")
    lazy val TailrecClass               = getClass("scala.annotation.tailrec")
    lazy val SwitchClass                = getClass("scala.annotation.switch")
    lazy val ElidableMethodClass        = getClass("scala.annotation.elidable")
    lazy val ImplicitNotFoundClass      = getClass("scala.annotation.implicitNotFound")
    lazy val VarargsClass               = getClass("scala.annotation.varargs")
    lazy val FieldTargetClass           = getClass("scala.annotation.target.field")
    lazy val GetterTargetClass          = getClass("scala.annotation.target.getter")
    lazy val SetterTargetClass          = getClass("scala.annotation.target.setter")
    lazy val BeanGetterTargetClass      = getClass("scala.annotation.target.beanGetter")
    lazy val BeanSetterTargetClass      = getClass("scala.annotation.target.beanSetter")
    lazy val ParamTargetClass           = getClass("scala.annotation.target.param")
    lazy val ScalaInlineClass           = getClass("scala.inline")
    lazy val ScalaNoInlineClass         = getClass("scala.noinline")
    lazy val SpecializedClass           = getClass("scala.specialized")
    lazy val BridgeClass                = getClass("scala.annotation.bridge") 

    // fundamental reference classes
    lazy val ScalaObjectClass     = getClass("scala.ScalaObject")
    lazy val PartialFunctionClass = getClass("scala.PartialFunction")
    lazy val SymbolClass          = getClass("scala.Symbol")
    lazy val StringClass          = getClass(sn.String)
    lazy val StringModule         = StringClass.linkedClassOfClass
    lazy val ClassClass           = getClass(sn.Class)
      def Class_getMethod = getMember(ClassClass, nme.getMethod_)
    lazy val DynamicClass         = getClass("scala.Dynamic")

    // fundamental modules
    lazy val PredefModule: Symbol = getModule("scala.Predef")
    lazy val PredefModuleClass = PredefModule.tpe.typeSymbol
      def Predef_AnyRef = getMember(PredefModule, "AnyRef") // used by the specialization annotation
      def Predef_classOf = getMember(PredefModule, nme.classOf)
      def Predef_error    = getMember(PredefModule, nme.error)
      def Predef_identity = getMember(PredefModule, nme.identity)
      def Predef_conforms = getMember(PredefModule, nme.conforms)
      def Predef_wrapRefArray = getMember(PredefModule, nme.wrapRefArray)
    lazy val ConsoleModule: Symbol = getModule("scala.Console")
    lazy val ScalaRunTimeModule: Symbol = getModule("scala.runtime.ScalaRunTime")
    lazy val SymbolModule: Symbol = getModule("scala.Symbol")
    lazy val Symbol_apply = getMember(SymbolModule, nme.apply)
      def SeqFactory = getMember(ScalaRunTimeModule, nme.Seq)
      def arrayApplyMethod = getMember(ScalaRunTimeModule, "array_apply")
      def arrayUpdateMethod = getMember(ScalaRunTimeModule, "array_update")
      def arrayLengthMethod = getMember(ScalaRunTimeModule, "array_length")
      def arrayCloneMethod = getMember(ScalaRunTimeModule, "array_clone")
      def ensureAccessibleMethod = getMember(ScalaRunTimeModule, "ensureAccessible")
      def scalaRuntimeHash = getMember(ScalaRunTimeModule, "hash")
      def scalaRuntimeAnyValClass = getMember(ScalaRunTimeModule, "anyValClass")
      def scalaRuntimeSameElements = getMember(ScalaRunTimeModule, nme.sameElements)
    
    // classes with special meanings
    lazy val NotNullClass     = getClass("scala.NotNull")
    lazy val DelayedInitClass = getClass("scala.DelayedInit")
      def delayedInitMethod = getMember(DelayedInitClass, nme.delayedInit)
      // a dummy value that communicates that a delayedInit call is compiler-generated
      // from phase UnCurry to phase Constructors
      def delayedInitArgVal = EmptyPackageClass.newValue(NoPosition, nme.delayedInitArg)
        .setInfo(UnitClass.tpe)
    
    lazy val TypeConstraintClass   = getClass("scala.annotation.TypeConstraint")
    lazy val SingletonClass        = newClass(ScalaPackageClass, tpnme.Singleton, anyparam) setFlag (ABSTRACT | TRAIT | FINAL)
    lazy val SerializableClass     = getClass("scala.Serializable")
    lazy val JavaSerializableClass = getClass(sn.JavaSerializable)
    lazy val ComparableClass       = getClass("java.lang.Comparable")
    
    lazy val RepeatedParamClass = newCovariantPolyClass(
      ScalaPackageClass,
      tpnme.REPEATED_PARAM_CLASS_NAME, 
      tparam => seqType(tparam.typeConstructor)
    )

    lazy val JavaRepeatedParamClass = newCovariantPolyClass(
      ScalaPackageClass,
      tpnme.JAVA_REPEATED_PARAM_CLASS_NAME, 
      tparam => arrayType(tparam.typeConstructor)
    )

    def isByNameParamType(tp: Type)        = tp.typeSymbol == ByNameParamClass
    def isScalaRepeatedParamType(tp: Type) = tp.typeSymbol == RepeatedParamClass
    def isJavaRepeatedParamType(tp: Type)  = tp.typeSymbol == JavaRepeatedParamClass
    def isRepeatedParamType(tp: Type)      = isScalaRepeatedParamType(tp) || isJavaRepeatedParamType(tp)
    
    def isScalaVarArgs(params: List[Symbol]) = params.nonEmpty && isScalaRepeatedParamType(params.last.tpe)
    def isVarArgsList(params: List[Symbol])  = params.nonEmpty && isRepeatedParamType(params.last.tpe)
    def isVarArgTypes(formals: List[Type])   = formals.nonEmpty && isRepeatedParamType(formals.last)

    def isPrimitiveArray(tp: Type) = tp match {
      case TypeRef(_, ArrayClass, arg :: Nil) => isValueClass(arg.typeSymbol)
      case _                                  => false
    }
    def isArrayOfSymbol(tp: Type, elem: Symbol) = tp match {
      case TypeRef(_, ArrayClass, arg :: Nil) => arg.typeSymbol == elem
      case _                                  => false
    }

    lazy val ByNameParamClass = newCovariantPolyClass(
      ScalaPackageClass,
      tpnme.BYNAME_PARAM_CLASS_NAME,
      tparam => AnyClass.typeConstructor
    )
    lazy val EqualsPatternClass = {
      val clazz = newClass(ScalaPackageClass, tpnme.EQUALS_PATTERN_NAME, Nil)
      clazz setInfo polyType(List(newTypeParam(clazz, 0)), ClassInfoType(anyparam, new Scope, clazz))
    }

    // collections classes
    lazy val ConsClass          = getClass("scala.collection.immutable.$colon$colon")
    lazy val IterableClass      = getClass("scala.collection.Iterable")
    lazy val IteratorClass      = getClass("scala.collection.Iterator")
    lazy val ListClass          = getClass("scala.collection.immutable.List")
    lazy val SeqClass           = getClass("scala.collection.Seq")
    lazy val StringBuilderClass = getClass("scala.collection.mutable.StringBuilder")
    lazy val TraversableClass   = getClass("scala.collection.Traversable")

    lazy val ListModule       = getModule("scala.collection.immutable.List")
      lazy val List_apply = getMember(ListModule, nme.apply)
    lazy val NilModule        = getModule("scala.collection.immutable.Nil")
    lazy val SeqModule        = getModule("scala.collection.Seq")      

    // arrays and their members
    lazy val ArrayModule  = getModule("scala.Array")
      def ArrayModule_overloadedApply = getMember(ArrayModule, nme.apply)
    lazy val ArrayClass   = getClass("scala.Array")
      def Array_apply      = getMember(ArrayClass, nme.apply)
      def Array_update     = getMember(ArrayClass, nme.update)
      def Array_length     = getMember(ArrayClass, nme.length)
      lazy val Array_clone = getMember(ArrayClass, nme.clone_)
    
    // reflection / structural types
    lazy val SoftReferenceClass     = getClass("java.lang.ref.SoftReference")
    lazy val WeakReferenceClass     = getClass("java.lang.ref.WeakReference")
    lazy val MethodClass            = getClass(sn.MethodAsObject)
      def methodClass_setAccessible = getMember(MethodClass, nme.setAccessible)
    lazy val EmptyMethodCacheClass  = getClass("scala.runtime.EmptyMethodCache")
    lazy val MethodCacheClass       = getClass("scala.runtime.MethodCache")
      def methodCache_find  = getMember(MethodCacheClass, nme.find_)
      def methodCache_add   = getMember(MethodCacheClass, nme.add_)

    // scala.reflect
    lazy val PartialManifestClass  = getClass("scala.reflect.ClassManifest")
    lazy val PartialManifestModule = getModule("scala.reflect.ClassManifest")
    lazy val FullManifestClass     = getClass("scala.reflect.Manifest")
    lazy val FullManifestModule    = getModule("scala.reflect.Manifest")
    lazy val OptManifestClass      = getClass("scala.reflect.OptManifest")
    lazy val NoManifest            = getModule("scala.reflect.NoManifest")
    lazy val CodeClass             = getClass(sn.Code)
    lazy val CodeModule            = getModule(sn.Code)
      def Code_lift = getMember(CodeModule, nme.lift_)

    lazy val ScalaSignatureAnnotation = getClass("scala.reflect.ScalaSignature")
    lazy val ScalaLongSignatureAnnotation = getClass("scala.reflect.ScalaLongSignature")
    
    // invoke dynamic support
    lazy val LinkageModule = getModule("java.dyn.Linkage")
      lazy val Linkage_invalidateCallerClass = getMember(LinkageModule, "invalidateCallerClass")
    lazy val DynamicDispatchClass = getModule("scala.runtime.DynamicDispatch")
      lazy val DynamicDispatch_DontSetTarget = getMember(DynamicDispatchClass, "DontSetTarget")

    // Option classes
    lazy val OptionClass: Symbol = getClass("scala.Option")
    lazy val SomeClass: Symbol   = getClass("scala.Some")
    lazy val NoneModule: Symbol  = getModule("scala.None")

    def isOptionType(tp: Type)  = cond(tp.normalize) { case TypeRef(_, OptionClass, List(_)) => true }
    def isSomeType(tp: Type)    = cond(tp.normalize) { case TypeRef(_,   SomeClass, List(_)) => true }
    def isNoneType(tp: Type)    = cond(tp.normalize) { case TypeRef(_,   NoneModule, List(_)) => true }

    def optionType(tp: Type)    = typeRef(OptionClass.typeConstructor.prefix, OptionClass, List(tp))
    def someType(tp: Type)      = typeRef(SomeClass.typeConstructor.prefix, SomeClass, List(tp))
    def symbolType              = typeRef(SymbolClass.typeConstructor.prefix, SymbolClass, List()) 
    def longType                = typeRef(LongClass.typeConstructor.prefix, LongClass, List()) 
    
    // Product, Tuple, Function
    private def mkArityArray(name: String, arity: Int, countFrom: Int = 1): Array[Symbol] = {
      val list = countFrom to arity map (i => getClass("scala." + name + i))
      if (countFrom == 0) list.toArray
      else (NoSymbol +: list).toArray
    }
    
    val MaxTupleArity, MaxProductArity, MaxFunctionArity = 22
    /** The maximal dimensions of a generic array creation.
     *  I.e. new Array[Array[Array[Array[Array[T]]]]] creates a 5 times
     *  nested array. More is not allowed.
     */
    val MaxArrayDims = 5
    lazy val TupleClass     = mkArityArray("Tuple", MaxTupleArity)
    lazy val ProductClass   = mkArityArray("Product", MaxProductArity)
    lazy val FunctionClass  = mkArityArray("Function", MaxFunctionArity, 0)
    lazy val AbstractFunctionClass = mkArityArray("runtime.AbstractFunction", MaxFunctionArity, 0)
    
      def tupleField(n: Int, j: Int) = getMember(TupleClass(n), "_" + j)
      def isTupleType(tp: Type): Boolean = isTupleType(tp, false)
      def isTupleTypeOrSubtype(tp: Type): Boolean = isTupleType(tp, true)
      private def isTupleType(tp: Type, subtypeOK: Boolean) = tp.normalize match {
        case TypeRef(_, sym, args) if args.nonEmpty =>
          val len = args.length
          len <= MaxTupleArity && {
            val tsym = TupleClass(len)
            (sym == tsym) || (subtypeOK && !tp.isHigherKinded && sym.isSubClass(tsym))
          }
        case _ => false
      }
      
      def tupleType(elems: List[Type]) = {
        val len = elems.length
        if (len <= MaxTupleArity) {
          val sym = TupleClass(len)
          typeRef(sym.typeConstructor.prefix, sym, elems)
        } else NoType
      }

    lazy val ProductRootClass: Symbol = getClass("scala.Product")
      def Product_productArity = getMember(ProductRootClass, nme.productArity)
      def Product_productElement = getMember(ProductRootClass, nme.productElement)
      // def Product_productElementName = getMember(ProductRootClass, nme.productElementName)
      def Product_productPrefix = getMember(ProductRootClass, nme.productPrefix)
      def Product_canEqual = getMember(ProductRootClass, nme.canEqual_)
      
      def productProj(z:Symbol, j: Int): Symbol = getMember(z, nme.productAccessorName(j))
      def productProj(n: Int,   j: Int): Symbol = productProj(ProductClass(n), j)
      
      /** returns true if this type is exactly ProductN[T1,...,Tn], not some subclass */
      def isExactProductType(tp: Type): Boolean = cond(tp.normalize) {
        case TypeRef(_, sym, elems) =>
          val len = elems.length
          len <= MaxProductArity && sym == ProductClass(len)
      }

      def productType(elems: List[Type]) = {
        if (elems.isEmpty) UnitClass.tpe
        else {
          val len = elems.length
          if (len <= MaxProductArity) {
            val sym = ProductClass(len)
            typeRef(sym.typeConstructor.prefix, sym, elems)
          }
          else NoType
        }
      }

    /** if tpe <: ProductN[T1,...,TN], returns Some(T1,...,TN) else None */
    def getProductArgs(tpe: Type): Option[List[Type]] = 
      tpe.baseClasses collectFirst { case x if isExactProductType(x.tpe) => tpe.baseType(x).typeArgs }

    def unapplyUnwrap(tpe:Type) = (tpe match {
      case PolyType(_,MethodType(_, res)) => res
      case MethodType(_, res)             => res
      case tpe                            => tpe
    }).normalize
    
    def functionApply(n: Int) = getMember(FunctionClass(n), nme.apply)
    def functionType(formals: List[Type], restpe: Type) = {
      val len = formals.length
      if (len <= MaxFunctionArity) {
        val sym = FunctionClass(len)
        typeRef(sym.typeConstructor.prefix, sym, formals :+ restpe)
      } else NoType
    }
  
    def abstractFunctionForFunctionType(tp: Type) = tp.normalize match {
      case tr @ TypeRef(_, _, args) if isFunctionType(tr) =>
        val sym = AbstractFunctionClass(args.length - 1)
        typeRef(sym.typeConstructor.prefix, sym, args)
      case _ =>
        NoType
    }

    def isFunctionType(tp: Type): Boolean = tp.normalize match {
      case TypeRef(_, sym, args) if args.nonEmpty =>
        val len = args.length
        len < MaxFunctionArity && sym == FunctionClass(len - 1)
      case _ =>
        false
    }
    
    def isSeqType(tp: Type) = elementType(SeqClass, tp.normalize) != NoType

    def elementType(container: Symbol, tp: Type): Type = tp match {
      case TypeRef(_, `container`, arg :: Nil)  => arg
      case _                                    => NoType
    }
    
    def seqType(arg: Type)    = typeRef(SeqClass.typeConstructor.prefix, SeqClass, List(arg))
    def arrayType(arg: Type)  = typeRef(ArrayClass.typeConstructor.prefix, ArrayClass, List(arg))
    def byNameType(arg: Type) = appliedType(ByNameParamClass.typeConstructor, List(arg))

    def ClassType(arg: Type) = 
      if (phase.erasedTypes || forMSIL) ClassClass.tpe
      else appliedType(ClassClass.tpe, List(arg))

    //
    // .NET backend
    //
    
    lazy val ComparatorClass = getClass("scala.runtime.Comparator")    
    // System.ValueType
    lazy val ValueTypeClass: Symbol = getClass(sn.ValueType)
    // System.MulticastDelegate
    lazy val DelegateClass: Symbol = getClass(sn.Delegate)
    var Delegate_scalaCallers: List[Symbol] = List()
    // Symbol -> (Symbol, Type): scalaCaller -> (scalaMethodSym, DelegateType)
    // var Delegate_scalaCallerInfos: HashMap[Symbol, (Symbol, Type)] = _
    lazy val Delegate_scalaCallerTargets: HashMap[Symbol, Symbol] = new HashMap()
    
    def isCorrespondingDelegate(delegateType: Type, functionType: Type): Boolean = {
      isSubType(delegateType, DelegateClass.tpe) &&
      (delegateType.member(nme.apply).tpe match {
      	case MethodType(delegateParams, delegateReturn) =>
      	  isFunctionType(functionType) &&
      	  (functionType.normalize match {
      	    case TypeRef(_, _, args) =>
      	      (delegateParams.map(pt => {
                      if (pt.tpe == AnyClass.tpe) definitions.ObjectClass.tpe else pt})
      	       ::: List(delegateReturn)) == args
      	    case _ => false
      	  })
        case _ => false
      })
    }

    // members of class scala.Any
    var Any_==          : Symbol = _
    var Any_!=          : Symbol = _
    var Any_equals      : Symbol = _
    var Any_hashCode    : Symbol = _
    var Any_toString    : Symbol = _
    var Any_getClass    : Symbol = _
    var Any_isInstanceOf: Symbol = _
    var Any_asInstanceOf: Symbol = _
    var Any_##          : Symbol = _

    // members of class java.lang.{Object, String}
    var Object_eq          : Symbol = _
    var Object_ne          : Symbol = _
    var Object_==          : Symbol = _
    var Object_!=          : Symbol = _
    var Object_##          : Symbol = _
    var Object_synchronized: Symbol = _
    lazy val Object_isInstanceOf = newPolyMethod(
      ObjectClass, "$isInstanceOf",
      tparam => MethodType(List(), booltype)) setFlag (FINAL | SYNTHETIC)
    lazy val Object_asInstanceOf = newPolyMethod(
      ObjectClass, "$asInstanceOf",
      tparam => MethodType(List(), tparam.typeConstructor)) setFlag (FINAL | SYNTHETIC)

    def Object_getClass  = getMember(ObjectClass, nme.getClass_)
    def Object_clone     = getMember(ObjectClass, nme.clone_)
    def Object_finalize  = getMember(ObjectClass, nme.finalize_)
    def Object_notify    = getMember(ObjectClass, nme.notify_)
    def Object_notifyAll = getMember(ObjectClass, nme.notifyAll_)
    def Object_equals    = getMember(ObjectClass, nme.equals_)
    def Object_hashCode  = getMember(ObjectClass, nme.hashCode_)
    def Object_toString  = getMember(ObjectClass, nme.toString_)

    var String_+           : Symbol = _

    // boxed classes
    lazy val ObjectRefClass         = getClass("scala.runtime.ObjectRef")
    lazy val VolatileObjectRefClass = getClass("scala.runtime.VolatileObjectRef")
    lazy val BoxesRunTimeClass      = getModule("scala.runtime.BoxesRunTime")
    lazy val BoxedNumberClass       = getClass(sn.BoxedNumber)
    lazy val BoxedCharacterClass    = getClass(sn.BoxedCharacter)
    lazy val BoxedBooleanClass      = getClass(sn.BoxedBoolean)
    lazy val BoxedByteClass         = getClass("java.lang.Byte")
    lazy val BoxedShortClass        = getClass("java.lang.Short")
    lazy val BoxedIntClass          = getClass("java.lang.Integer")
    lazy val BoxedLongClass         = getClass("java.lang.Long")
    lazy val BoxedFloatClass        = getClass("java.lang.Float")
    lazy val BoxedDoubleClass       = getClass("java.lang.Double")
    
    lazy val BoxedUnitClass         = getClass("scala.runtime.BoxedUnit")
    lazy val BoxedUnitModule        = getModule("scala.runtime.BoxedUnit")
      def BoxedUnit_UNIT = getMember(BoxedUnitModule, "UNIT")
      def BoxedUnit_TYPE = getMember(BoxedUnitModule, "TYPE")

    // special attributes
    lazy val BeanPropertyAttr: Symbol           = getClass(sn.BeanProperty)
    lazy val BooleanBeanPropertyAttr: Symbol    = getClass(sn.BooleanBeanProperty)
    lazy val CloneableAttr: Symbol              = getClass("scala.cloneable")
    lazy val DeprecatedAttr: Symbol             = getClass("scala.deprecated")
    lazy val DeprecatedNameAttr: Symbol         = getClass("scala.deprecatedName")
    lazy val MigrationAnnotationClass: Symbol   = getClass("scala.annotation.migration")
    lazy val NativeAttr: Symbol                 = getClass("scala.native")
    lazy val RemoteAttr: Symbol                 = getClass("scala.remote")
    lazy val ScalaNumberClass: Symbol           = getClass("scala.math.ScalaNumber")
    lazy val ScalaStrictFPAttr: Symbol          = getClass("scala.annotation.strictfp")
    lazy val SerialVersionUIDAttr: Symbol       = getClass("scala.SerialVersionUID")
    lazy val SerializableAttr: Symbol           = getClass("scala.annotation.serializable") // @serializable is deprecated
    lazy val TraitSetterAnnotationClass: Symbol = getClass("scala.runtime.TraitSetter")
    lazy val TransientAttr: Symbol              = getClass("scala.transient")
    lazy val VolatileAttr: Symbol               = getClass("scala.volatile")
    
    lazy val AnnotationDefaultAttr: Symbol = {
      val attr = newClass(RuntimePackageClass, tpnme.AnnotationDefaultATTR, List(AnnotationClass.typeConstructor))
      // This attribute needs a constructor so that modifiers in parsed Java code make sense
      attr.info.decls enter (attr newConstructor NoPosition setInfo MethodType(Nil, attr.tpe))
      attr
    }

    def getModule(fullname: Name): Symbol =
      getModuleOrClass(fullname.toTermName)

    def getClass(fullname: Name): Symbol = {
      var result = getModuleOrClass(fullname.toTypeName)
      while (result.isAliasType) result = result.info.typeSymbol
      result
    }
    
    def getClassIfDefined(fullname: Name): Symbol = 
      try {
        getClass(fullname)
      } catch {
        case ex: MissingRequirementError => NoSymbol
      }

    def getMember(owner: Symbol, name: Name): Symbol = {
      if (owner == NoSymbol) NoSymbol
      else owner.info.nonPrivateMember(name) match {
        case NoSymbol => throw new FatalError(owner + " does not have a member " + name)
        case result   => result
      }
    }
    def packageExists(packageName: String): Boolean = {
      try getModuleOrClass(newTermName(packageName)).isPackage
      catch { case _: MissingRequirementError => false }
    }
    
    /** If you're looking for a class, pass a type name.
     *  If a module, a term name.
     */
    private def getModuleOrClass(path: Name): Symbol = {
      val module   = path.isTermName
      val fullname = path.toTermName
      if (fullname == nme.NO_NAME)
        return NoSymbol
        
      var sym: Symbol = RootClass
      var i = 0
      var j = fullname.pos('.', i)
      while (j < fullname.length) {
        sym = sym.info.member(fullname.subName(i, j))
        i = j + 1
        j = fullname.pos('.', i)
      }
      val result =
        if (module) sym.info.member(fullname.subName(i, j)).suchThat(_ hasFlag MODULE)
        else sym.info.member(fullname.subName(i, j).toTypeName)
      if (result == NoSymbol) {
        if (settings.debug.value)
          { log(sym.info); log(sym.info.members) }//debug
        throw new MissingRequirementError((if (module) "object " else "class ") + fullname)
      }
      result
    }

    private def newClass(owner: Symbol, name: TypeName, parents: List[Type]): Symbol = {
      val clazz = owner.newClass(NoPosition, name)
      clazz.setInfo(ClassInfoType(parents, new Scope, clazz))
      owner.info.decls.enter(clazz) 
      clazz
    }

    private def newCovariantPolyClass(owner: Symbol, name: TypeName, parent: Symbol => Type): Symbol = {
      val clazz  = newClass(owner, name, List())
      val tparam = newTypeParam(clazz, 0) setFlag COVARIANT
      val p      = parent(tparam)
/*      p.typeSymbol.initialize
      println(p.typeSymbol + " flags: " + Flags.flagsToString(p.typeSymbol.flags))
      val parents = /*if (p.typeSymbol.isTrait)
        List(definitions.AnyRefClass.tpe, p) 
                    else*/ List(p)
      println("creating " + name + " with parents " + parents) */
      clazz.setInfo(
        polyType(
          List(tparam),
          ClassInfoType(List(AnyRefClass.tpe, p), new Scope, clazz)))
    }

    private def newAlias(owner: Symbol, name: TypeName, alias: Type): Symbol = {
      val tpsym = owner.newAliasType(NoPosition, name)
      tpsym.setInfo(alias)
      owner.info.decls.enter(tpsym)
      tpsym
    }

    private def newMethod(owner: Symbol, name: TermName): Symbol = {
      val msym = owner.newMethod(NoPosition, name.encode)
      owner.info.decls.enter(msym)
      msym
    }

    private[Definitions] def newMethod(owner: Symbol, name: TermName, formals: List[Type], restpe: Type): Symbol = {
      val msym = newMethod(owner, name)
      val params = msym.newSyntheticValueParams(formals)
      msym.setInfo(MethodType(params, restpe))
    }

    /** tcon receives the type parameter symbol as argument */
    private def newPolyMethod(owner: Symbol, name: TermName, tcon: Symbol => Type): Symbol =
      newPolyMethodCon(owner, name, tparam => msym => tcon(tparam))

    /** tcon receives the type parameter symbol and the method symbol as arguments */
    private def newPolyMethodCon(owner: Symbol, name: TermName, tcon: Symbol => Symbol => Type): Symbol = {
      val msym = newMethod(owner, name)
      val tparam = newTypeParam(msym, 0)
      msym.setInfo(polyType(List(tparam), tcon(tparam)(msym)))
    }

    private def newParameterlessMethod(owner: Symbol, name: TermName, restpe: Type) =
      newMethod(owner, name).setInfo(NullaryMethodType(restpe))

    private def newTypeParam(owner: Symbol, index: Int): Symbol =
      owner.newTypeParameter(NoPosition, newTypeName("T" + index)) setInfo TypeBounds.empty

    lazy val boxedClassValues = boxedClass.values.toSet
    lazy val isUnbox = unboxMethod.values.toSet
    lazy val isBox = boxMethod.values.toSet

    /** Is symbol a phantom class for which no runtime representation exists? */
    lazy val isPhantomClass = Set[Symbol](AnyClass, AnyValClass, NullClass, NothingClass)

    private lazy val scalaValueClassesSet = ScalaValueClasses.toSet
    private lazy val boxedValueClassesSet = boxedClass.values.toSet + BoxedUnitClass

    /** Is symbol a value class? */
    def isValueClass(sym: Symbol) = scalaValueClassesSet(sym)
    def isNonUnitValueClass(sym: Symbol) = (sym != UnitClass) && isValueClass(sym)
    def isScalaValueType(tp: Type) = scalaValueClassesSet(tp.typeSymbol)
      
    /** Is symbol a boxed value class, e.g. java.lang.Integer? */
    def isBoxedValueClass(sym: Symbol) = boxedValueClassesSet(sym)
    
    /** If symbol is a value class, return the value class, with the exception
     *  that BoxedUnit remains BoxedUnit.  If not a value class, NoSymbol.
     */    
    def unboxedValueClass(sym: Symbol): Symbol =
      if (isValueClass(sym)) sym
      else if (sym == BoxedUnitClass) sym
      else boxedClass.map(_.swap).getOrElse(sym, NoSymbol)

    /** Is type's symbol a numeric value class? */
    def isNumericValueType(tp: Type): Boolean = tp match {
      case TypeRef(_, sym, _) => isNumericValueClass(sym)
      case _ => false
    }

    // todo: reconcile with javaSignature!!!
    def signature(tp: Type): String = {
      def erasure(tp: Type): Type = tp match {
        case st: SubType => erasure(st.supertype)
        case RefinedType(parents, _) => erasure(parents.head)
        case _ => tp
      }
      def flatNameString(sym: Symbol, separator: Char): String =
        if (sym == NoSymbol) ""   // be more resistant to error conditions, e.g. neg/t3222.scala
        else if (sym.owner.isPackageClass) sym.fullName('.') + (if (sym.isModuleClass) "$" else "")
        else flatNameString(sym.owner, separator) + "$" + sym.simpleName;
      def signature1(etp: Type): String = {
        if (etp.typeSymbol == ArrayClass) "[" + signature1(erasure(etp.normalize.typeArgs.head))
        else if (isValueClass(etp.typeSymbol)) abbrvTag(etp.typeSymbol).toString()
        else "L" + flatNameString(etp.typeSymbol, '/') + ";"
      }
      val etp = erasure(tp)
      if (etp.typeSymbol == ArrayClass) signature1(etp)
      else flatNameString(etp.typeSymbol, '.')
    }
    
    /** getModule2/getClass2 aren't needed at present but may be again,
     *  so for now they're mothballed.
     */
    // def getModule2(name1: Name, name2: Name) = {
    //   try getModuleOrClass(name1.toTermName)
    //   catch { case ex1: FatalError =>
    //     try getModuleOrClass(name2.toTermName)
    //     catch { case ex2: FatalError => throw ex1 }
    //   }
    // }
    // def getClass2(name1: Name, name2: Name) = {
    //   try {
    //     val result = getModuleOrClass(name1.toTypeName)
    //     if (result.isAliasType) getClass(name2) else result
    //   }
    //   catch { case ex1: FatalError =>
    //     try getModuleOrClass(name2.toTypeName)
    //     catch { case ex2: FatalError => throw ex1 }
    //   }
    // }
    
    /** Surgery on the value classes.  Without this, AnyVals defined in source
     *  files end up with an AnyRef parent.  It is likely there is a better way
     *  to evade that AnyRef.
     */
    private def setParents(sym: Symbol, parents: List[Type]): Symbol = sym.rawInfo match {
      case ClassInfoType(_, scope, clazz) =>
        sym setInfo ClassInfoType(parents, scope, clazz)
      case _ =>
        sym
    }

    def init() {
      if (isInitialized) return

      EmptyPackageClass setInfo ClassInfoType(Nil, new Scope, EmptyPackageClass)
      EmptyPackage setInfo EmptyPackageClass.tpe

      RootClass.info.decls enter EmptyPackage
      RootClass.info.decls enter RootPackage

      // members of class scala.Any
      Any_== = newMethod(AnyClass, nme.EQ, anyparam, booltype) setFlag FINAL
      Any_!= = newMethod(AnyClass, nme.NE, anyparam, booltype) setFlag FINAL
      Any_equals   = newMethod(AnyClass, nme.equals_, anyparam, booltype)
      Any_hashCode = newMethod(AnyClass, nme.hashCode_, Nil, inttype)
      Any_toString = newMethod(AnyClass, nme.toString_, Nil, stringtype)
      Any_##       = newMethod(AnyClass, nme.HASHHASH, Nil, inttype) setFlag FINAL
      
      // Any_getClass requires special handling.  The return type is determined on
      // a per-call-site basis as if the function being called were actually:
      //
      //    // Assuming `target.getClass()`
      //    def getClass[T](target: T): Class[_ <: T]
      //
      // Since getClass is not actually a polymorphic method, this requires compiler
      // participation.  At the "Any" level, the return type is Class[_] as it is in 
      // java.lang.Object.  Java also special cases the return type.
      Any_getClass = {
        val eparams = typeParamsToExistentials(ClassClass, ClassClass.typeParams)
        eparams.head setInfo TypeBounds.empty
        val tpe = existentialAbstraction(eparams, appliedType(ClassClass.tpe, List(eparams.head.tpe)))
      
        newMethod(AnyClass, nme.getClass_, Nil, tpe) setFlag DEFERRED
      }
      Any_isInstanceOf = newPolyMethod(
        AnyClass, nme.isInstanceOf_, tparam => NullaryMethodType(booltype)) setFlag FINAL
      Any_asInstanceOf = newPolyMethod(
        AnyClass, nme.asInstanceOf_, tparam => NullaryMethodType(tparam.typeConstructor)) setFlag FINAL

      // members of class java.lang.{ Object, String }
      Object_## = newMethod(ObjectClass, nme.HASHHASH, Nil, inttype) setFlag FINAL
      Object_== = newMethod(ObjectClass, nme.EQ, anyrefparam, booltype) setFlag FINAL
      Object_!= = newMethod(ObjectClass, nme.NE, anyrefparam, booltype) setFlag FINAL
      Object_eq = newMethod(ObjectClass, nme.eq, anyrefparam, booltype) setFlag FINAL
      Object_ne = newMethod(ObjectClass, nme.ne, anyrefparam, booltype) setFlag FINAL
      Object_synchronized = newPolyMethodCon(
        ObjectClass, nme.synchronized_,
        tparam => msym => MethodType(msym.newSyntheticValueParams(List(tparam.typeConstructor)), tparam.typeConstructor)) setFlag FINAL

      String_+ = newMethod(
        StringClass, "+", anyparam, stringtype) setFlag FINAL

      val forced = List( // force initialization of every symbol that is entered as a side effect
        AnnotationDefaultAttr, // #2264
        RepeatedParamClass,
        JavaRepeatedParamClass,
        ByNameParamClass,
        AnyClass,
        AnyRefClass,
        AnyValClass,
        NullClass,
        NothingClass,
        SingletonClass,
        EqualsPatternClass,
        Object_isInstanceOf,
        Object_asInstanceOf
      )
      
      /** Removing the anyref parent they acquire from having a source file.
       */
      setParents(AnyValClass, anyparam)
      ScalaValueClasses foreach { sym =>
        setParents(sym, anyvalparam)
      }

      isInitialized = true
    } //init

    var nbScalaCallers: Int = 0
    def newScalaCaller(delegateType: Type): Symbol = {
      assert(forMSIL, "scalaCallers can only be created if target is .NET")
      // object: reference to object on which to call (scala-)method
      val paramTypes: List[Type] = List(ObjectClass.tpe)
      val name: String =  "$scalaCaller$$" + nbScalaCallers
      // tparam => resultType, which is the resultType of PolyType, i.e. the result type after applying the
      // type parameter =-> a MethodType in this case
      // TODO: set type bounds manually (-> MulticastDelegate), see newTypeParam
      val newCaller = newMethod(DelegateClass, name, paramTypes, delegateType) setFlag (FINAL | STATIC)
      // val newCaller = newPolyMethod(DelegateClass, name,
      // tparam => MethodType(paramTypes, tparam.typeConstructor)) setFlag (FINAL | STATIC)
      Delegate_scalaCallers = Delegate_scalaCallers ::: List(newCaller)
      nbScalaCallers += 1
      newCaller
    }

    // def addScalaCallerInfo(scalaCaller: Symbol, methSym: Symbol, delType: Type) {
    // assert(Delegate_scalaCallers contains scalaCaller)
    // Delegate_scalaCallerInfos += (scalaCaller -> (methSym, delType))
    // }

    def addScalaCallerInfo(scalaCaller: Symbol, methSym: Symbol) {
      assert(Delegate_scalaCallers contains scalaCaller)
      Delegate_scalaCallerTargets += (scalaCaller -> methSym)
    }
  }
}

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