Merge pull request #5935 from dotty-staging/drop-andor-typetree

Drop AndTypeTree and OrTypeTree

Author: odersky

compiler/src/dotty/tools/dotc/ast/Desugar.scala

@@ -1440,7 +1440,7 @@ object desugar {
     def collect(tree: Tree): Unit = tree match {
       case Bind(nme.WILDCARD, tree1) =>
         collect(tree1)
-      case tree @ Bind(_, Typed(tree1, tpt)) if !mayBeTypePat(tpt) =>
+      case tree @ Bind(_, Typed(tree1, tpt)) =>
         add(tree, tpt)
         collect(tree1)
       case tree @ Bind(_, tree1) =>

compiler/src/dotty/tools/dotc/ast/DesugarEnums.scala

@@ -154,7 +154,7 @@ object DesugarEnums {
     parentTypes.head match {
       case parent: RefTree if parent.name == enumClass.name =>
         // need a widen method to compute correct type parameters for enum base class
-        val widenParamType = (appliedEnumRef /: parentTypes.tail)(AndTypeTree)
+        val widenParamType = (appliedEnumRef /: parentTypes.tail)(makeAndType)
         val widenParam = makeSyntheticParameter(tpt = widenParamType)
         val widenDef = DefDef(
           name = s"${cdef.name}$$to$$${enumClass.name}".toTermName,
@@ -164,7 +164,7 @@ object DesugarEnums {
           rhs = Ident(widenParam.name))
         (TypeTree(), widenDef :: Nil)
       case _ =>
-        (parentTypes.reduceLeft(AndTypeTree), Nil)
+        (parentTypes.reduceLeft(makeAndType), Nil)
     }
   }
 

compiler/src/dotty/tools/dotc/ast/TreeInfo.scala

@@ -164,17 +164,6 @@ trait TreeInfo[T >: Untyped <: Type] { self: Trees.Instance[T] =>
   /** Is name a left-associative operator? */
   def isLeftAssoc(operator: Name): Boolean = !operator.isEmpty && (operator.toSimpleName.last != ':')
 
-  /** can this type be a type pattern? */
-  def mayBeTypePat(tree: Tree): Boolean = unsplice(tree) match {
-    case AndTypeTree(tpt1, tpt2) => mayBeTypePat(tpt1) || mayBeTypePat(tpt2)
-    case OrTypeTree(tpt1, tpt2) => mayBeTypePat(tpt1) || mayBeTypePat(tpt2)
-    case RefinedTypeTree(tpt, refinements) => mayBeTypePat(tpt) || refinements.exists(_.isInstanceOf[Bind])
-    case AppliedTypeTree(tpt, args) => mayBeTypePat(tpt) || args.exists(_.isInstanceOf[Bind])
-    case Select(tpt, _) => mayBeTypePat(tpt)
-    case Annotated(tpt, _) => mayBeTypePat(tpt)
-    case _ => false
-  }
-
   /** Is this argument node of the form <expr> : _*, or is it a reference to
    *  such an argument ? The latter case can happen when an argument is lifted.
    */

compiler/src/dotty/tools/dotc/ast/Trees.scala

@@ -626,18 +626,6 @@ object Trees {
     type ThisTree[-T >: Untyped] = SingletonTypeTree[T]
   }
 
-  /** left & right */
-  case class AndTypeTree[-T >: Untyped] private[ast] (left: Tree[T], right: Tree[T])(implicit @constructorOnly src: SourceFile)
-    extends TypTree[T] {
-    type ThisTree[-T >: Untyped] = AndTypeTree[T]
-  }
-
-  /** left | right */
-  case class OrTypeTree[-T >: Untyped] private[ast] (left: Tree[T], right: Tree[T])(implicit @constructorOnly src: SourceFile)
-    extends TypTree[T] {
-    type ThisTree[-T >: Untyped] = OrTypeTree[T]
-  }
-
   /** tpt { refinements } */
   case class RefinedTypeTree[-T >: Untyped] private[ast] (tpt: Tree[T], refinements: List[Tree[T]])(implicit @constructorOnly src: SourceFile)
     extends ProxyTree[T] with TypTree[T] {
@@ -934,8 +922,6 @@ object Trees {
     type Inlined = Trees.Inlined[T]
     type TypeTree = Trees.TypeTree[T]
     type SingletonTypeTree = Trees.SingletonTypeTree[T]
-    type AndTypeTree = Trees.AndTypeTree[T]
-    type OrTypeTree = Trees.OrTypeTree[T]
     type RefinedTypeTree = Trees.RefinedTypeTree[T]
     type AppliedTypeTree = Trees.AppliedTypeTree[T]
     type LambdaTypeTree = Trees.LambdaTypeTree[T]
@@ -1102,14 +1088,6 @@ object Trees {
         case tree: SingletonTypeTree if (ref eq tree.ref) => tree
         case _ => finalize(tree, untpd.SingletonTypeTree(ref)(sourceFile(tree)))
       }
-      def AndTypeTree(tree: Tree)(left: Tree, right: Tree)(implicit ctx: Context): AndTypeTree = tree match {
-        case tree: AndTypeTree if (left eq tree.left) && (right eq tree.right) => tree
-        case _ => finalize(tree, untpd.AndTypeTree(left, right)(sourceFile(tree)))
-      }
-      def OrTypeTree(tree: Tree)(left: Tree, right: Tree)(implicit ctx: Context): OrTypeTree = tree match {
-        case tree: OrTypeTree if (left eq tree.left) && (right eq tree.right) => tree
-        case _ => finalize(tree, untpd.OrTypeTree(left, right)(sourceFile(tree)))
-      }
       def RefinedTypeTree(tree: Tree)(tpt: Tree, refinements: List[Tree])(implicit ctx: Context): RefinedTypeTree = tree match {
         case tree: RefinedTypeTree if (tpt eq tree.tpt) && (refinements eq tree.refinements) => tree
         case _ => finalize(tree, untpd.RefinedTypeTree(tpt, refinements)(sourceFile(tree)))
@@ -1271,10 +1249,6 @@ object Trees {
               tree
             case SingletonTypeTree(ref) =>
               cpy.SingletonTypeTree(tree)(transform(ref))
-            case AndTypeTree(left, right) =>
-              cpy.AndTypeTree(tree)(transform(left), transform(right))
-            case OrTypeTree(left, right) =>
-              cpy.OrTypeTree(tree)(transform(left), transform(right))
             case RefinedTypeTree(tpt, refinements) =>
               cpy.RefinedTypeTree(tree)(transform(tpt), transformSub(refinements))
             case AppliedTypeTree(tpt, args) =>
@@ -1399,10 +1373,6 @@ object Trees {
               x
             case SingletonTypeTree(ref) =>
               this(x, ref)
-            case AndTypeTree(left, right) =>
-              this(this(x, left), right)
-            case OrTypeTree(left, right) =>
-              this(this(x, left), right)
             case RefinedTypeTree(tpt, refinements) =>
               this(this(x, tpt), refinements)
             case AppliedTypeTree(tpt, args) =>

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

@@ -161,12 +161,6 @@ object tpd extends Trees.Instance[Type] with TypedTreeInfo {
   def SingletonTypeTree(ref: Tree)(implicit ctx: Context): SingletonTypeTree =
     ta.assignType(untpd.SingletonTypeTree(ref), ref)
 
-  def AndTypeTree(left: Tree, right: Tree)(implicit ctx: Context): AndTypeTree =
-    ta.assignType(untpd.AndTypeTree(left, right), left, right)
-
-  def OrTypeTree(left: Tree, right: Tree)(implicit ctx: Context): OrTypeTree =
-    ta.assignType(untpd.OrTypeTree(left, right), left, right)
-
   def RefinedTypeTree(parent: Tree, refinements: List[Tree], refineCls: ClassSymbol)(implicit ctx: Context): Tree =
     ta.assignType(untpd.RefinedTypeTree(parent, refinements), parent, refinements, refineCls)
 

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

@@ -309,8 +309,6 @@ object untpd extends Trees.Instance[Untyped] with UntypedTreeInfo {
   def Inlined(call: tpd.Tree, bindings: List[MemberDef], expansion: Tree)(implicit src: SourceFile): Inlined = new Inlined(call, bindings, expansion)
   def TypeTree()(implicit src: SourceFile): TypeTree = new TypeTree()
   def SingletonTypeTree(ref: Tree)(implicit src: SourceFile): SingletonTypeTree = new SingletonTypeTree(ref)
-  def AndTypeTree(left: Tree, right: Tree)(implicit src: SourceFile): AndTypeTree = new AndTypeTree(left, right)
-  def OrTypeTree(left: Tree, right: Tree)(implicit src: SourceFile): OrTypeTree = new OrTypeTree(left, right)
   def RefinedTypeTree(tpt: Tree, refinements: List[Tree])(implicit src: SourceFile): RefinedTypeTree = new RefinedTypeTree(tpt, refinements)
   def AppliedTypeTree(tpt: Tree, args: List[Tree])(implicit src: SourceFile): AppliedTypeTree = new AppliedTypeTree(tpt, args)
   def LambdaTypeTree(tparams: List[TypeDef], body: Tree)(implicit src: SourceFile): LambdaTypeTree = new LambdaTypeTree(tparams, body)
@@ -403,6 +401,9 @@ object untpd extends Trees.Instance[Untyped] with UntypedTreeInfo {
     case _ => Tuple(ts)
   }
 
+  def makeAndType(left: Tree, right: Tree)(implicit ctx: Context): AppliedTypeTree =
+    AppliedTypeTree(ref(defn.andType.typeRef), left :: right :: Nil)
+
   def makeParameter(pname: TermName, tpe: Tree, mods: Modifiers = EmptyModifiers)(implicit ctx: Context): ValDef =
     ValDef(pname, tpe, EmptyTree).withMods(mods | Param)
 

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

@@ -153,6 +153,11 @@ class Definitions {
     sym
   }
 
+  private def enterBinaryAlias(name: TypeName, op: (Type, Type) => Type): TypeSymbol =
+    enterAliasType(name,
+      HKTypeLambda(TypeBounds.empty :: TypeBounds.empty :: Nil)(
+      tl => op(tl.paramRefs(0), tl.paramRefs(1))))
+
   private def enterPolyMethod(cls: ClassSymbol, name: TermName, typeParamCount: Int,
                     resultTypeFn: PolyType => Type, flags: FlagSet = EmptyFlags,
                     useCompleter: Boolean = false) = {
@@ -323,6 +328,9 @@ class Definitions {
   }
   def AnyKindType: TypeRef = AnyKindClass.typeRef
 
+  lazy val andType: TypeSymbol = enterBinaryAlias(tpnme.AND, AndType(_, _))
+  lazy val orType: TypeSymbol = enterBinaryAlias(tpnme.OR, OrType(_, _))
+
   /** Marker method to indicate an argument to a call-by-name parameter.
    *  Created by byNameClosures and elimByName, eliminated by Erasure,
    */
@@ -1327,6 +1335,8 @@ class Definitions {
     AnyClass,
     AnyRefAlias,
     AnyKindClass,
+    andType,
+    orType,
     RepeatedParamClass,
     ByNameParamClass2x,
     AnyValClass,

compiler/src/dotty/tools/dotc/core/tasty/TastyFormat.scala

@@ -106,8 +106,6 @@ Standard-Section: "ASTs" TopLevelStat*
                   LAMBDAtpt      Length TypeParam* body_Term
                   TYPEBOUNDStpt  Length low_Term high_Term?
                   ANNOTATEDtpt   Length underlying_Term fullAnnotation_Term
-                  ANDtpt         Length left_Term right_Term
-                  ORtpt          Length left_Term right_Term
                   MATCHtpt       Length bound_Term? sel_Term CaseDef*
                   BYNAMEtpt             underlying_Term
                   SHAREDterm            term_ASTRef
@@ -246,7 +244,7 @@ Standard Section: "Comments" Comment*
 object TastyFormat {
 
   final val header: Array[Int] = Array(0x5C, 0xA1, 0xAB, 0x1F)
-  val MajorVersion: Int = 12
+  val MajorVersion: Int = 13
   val MinorVersion: Int = 0
 
   /** Tags used to serialize names */
@@ -419,9 +417,7 @@ object TastyFormat {
   final val TYPEBOUNDS = 163
   final val TYPEBOUNDStpt = 164
   final val ANDtype = 165
-  final val ANDtpt = 166
   final val ORtype = 167
-  final val ORtpt = 168
   final val POLYtype = 169
   final val TYPELAMBDAtype = 170
   final val LAMBDAtpt = 171
@@ -517,8 +513,6 @@ object TastyFormat {
        | LAMBDAtpt
        | TYPEBOUNDStpt
        | ANNOTATEDtpt
-       | ANDtpt
-       | ORtpt
        | BYNAMEtpt
        | MATCHtpt
        | BIND => true
@@ -647,9 +641,7 @@ object TastyFormat {
     case TYPEBOUNDStpt => "TYPEBOUNDStpt"
     case TYPEALIAS => "TYPEALIAS"
     case ANDtype => "ANDtype"
-    case ANDtpt => "ANDtpt"
     case ORtype => "ORtype"
-    case ORtpt => "ORtpt"
     case BYNAMEtype => "BYNAMEtype"
     case BYNAMEtpt => "BYNAMEtpt"
     case POLYtype => "POLYtype"

compiler/src/dotty/tools/dotc/core/tasty/TreePickler.scala

@@ -559,12 +559,6 @@ class TreePickler(pickler: TastyPickler) {
         case AppliedTypeTree(tycon, args) =>
           writeByte(APPLIEDtpt)
           withLength { pickleTree(tycon); args.foreach(pickleTree) }
-        case AndTypeTree(tp1, tp2) =>
-          writeByte(ANDtpt)
-          withLength { pickleTree(tp1); pickleTree(tp2) }
-        case OrTypeTree(tp1, tp2) =>
-          writeByte(ORtpt)
-          withLength { pickleTree(tp1); pickleTree(tp2) }
         case MatchTypeTree(bound, selector, cases) =>
           writeByte(MATCHtpt)
           withLength {

compiler/src/dotty/tools/dotc/core/tasty/TreeUnpickler.scala

@@ -1175,14 +1175,11 @@ class TreeUnpickler(reader: TastyReader,
               // types. This came up in #137 of collection strawman.
               val tycon = readTpt()
               val args = until(end)(readTpt())
-              untpd.AppliedTypeTree(tycon, args).withType(tycon.tpe.safeAppliedTo(args.tpes))
-            case ANDtpt =>
-              val tpt1 = readTpt()
-              val tpt2 = readTpt()
-              // FIXME: We need to do this instead of "AndType(tpt1, tpt2)" to avoid self-type cyclic reference in tasty_tools
-              untpd.AndTypeTree(tpt1, tpt2).withType(AndType(tpt1.tpe, tpt2.tpe))
-            case ORtpt =>
-              OrTypeTree(readTpt(), readTpt())
+              val ownType =
+                if (tycon.symbol == defn.andType) AndType(args(0).tpe, args(1).tpe)
+                else if (tycon.symbol == defn.orType) OrType(args(0).tpe, args(1).tpe)
+                else tycon.tpe.safeAppliedTo(args.tpes)
+              untpd.AppliedTypeTree(tycon, args).withType(ownType)
             case ANNOTATEDtpt =>
               Annotated(readTpt(), readTerm())
             case LAMBDAtpt =>