Make more types have safe equality.

Author: odersky

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

@@ -6,7 +6,7 @@ import util.DotClass
 
 /** A base class for things that have positions (currently: modifiers and trees)
  */
-abstract class Positioned extends DotClass with Product {
+abstract class Positioned extends DotClass with Product with EqClass[Positioned] {
 
   private[this] var curPos: Position = _
 

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

@@ -32,8 +32,8 @@ trait TreeInfo[T >: Untyped <: Type] { self: Trees.Instance[T] =>
   def defKind(tree: Tree): FlagSet = unsplice(tree) match {
     case EmptyTree | _: Import => NoInitsInterface
     case tree: TypeDef => if (tree.isClassDef) NoInits else NoInitsInterface
-    case tree: DefDef => if (tree.unforcedRhs == EmptyTree) NoInitsInterface else NoInits
-    case tree: ValDef => if (tree.unforcedRhs == EmptyTree) NoInitsInterface else EmptyFlags
+    case tree: DefDef => if (tree.unforcedRhs eq EmptyTree) NoInitsInterface else NoInits
+    case tree: ValDef => if (tree.unforcedRhs eq EmptyTree) NoInitsInterface else EmptyFlags
     case _ => EmptyFlags
   }
 
@@ -254,7 +254,7 @@ trait TreeInfo[T >: Untyped <: Type] { self: Trees.Instance[T] =>
    */
   def lacksDefinition(mdef: MemberDef)(implicit ctx: Context) = mdef match {
     case mdef: ValOrDefDef =>
-      mdef.unforcedRhs == EmptyTree && !mdef.name.isConstructorName && !mdef.mods.is(ParamAccessor)
+      (mdef.unforcedRhs eq EmptyTree) && !mdef.name.isConstructorName && !mdef.mods.is(ParamAccessor)
     case mdef: TypeDef =>
       mdef.rhs.isEmpty || mdef.rhs.isInstanceOf[TypeBoundsTree]
     case _ => false

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

@@ -8,7 +8,7 @@ import dotty.tools.dotc.ast.{tpd, untpd}
 
 object Annotations {
 
-  abstract class Annotation {
+  abstract class Annotation extends EqClass[Annotation] {
     def tree(implicit ctx: Context): Tree
     def symbol(implicit ctx: Context): Symbol =
       if (tree.symbol.isConstructor) tree.symbol.owner

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

@@ -22,7 +22,7 @@ object Constants {
   // For supporting java enumerations inside java annotations (see ClassfileParser)
   final val EnumTag    = 13
 
-  case class Constant(value: Any) extends printing.Showable {
+  case class Constant(value: Any) extends printing.Showable with EqClass[Constant] {
     import java.lang.Double.doubleToRawLongBits
     import java.lang.Float.floatToRawIntBits
 

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

@@ -60,7 +60,8 @@ object Contexts {
                             with SymDenotations
                             with Reporting
                             with NamerContextOps
-                            with Cloneable { thiscontext =>
+                            with Cloneable
+                            with EqClass[Context] { thiscontext =>
     implicit def ctx: Context = this
 
     /** The context base at the root */

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

@@ -12,7 +12,7 @@ object Flags {
    *  that has the intersection of the applicability to terms/types
    *  of the two flag sets. It is checked that the intersection is not empty.
    */
-  case class FlagSet(val bits: Long) extends AnyVal {
+  case class FlagSet(val bits: Long) extends AnyVal with EqClass[FlagSet] {
 
     /** The union of this flag set and the given flag set
      */
@@ -121,7 +121,7 @@ object Flags {
    *  conjunctively. I.e. for a flag conjunction `fc`,
    *  `x is fc` tests whether `x` contains all flags in `fc`.
    */
-  case class FlagConjunction(bits: Long) {
+  case class FlagConjunction(bits: Long) extends EqClass[FlagConjunction] {
     override def toString = FlagSet(bits).toString
   }
 

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

@@ -1,7 +1,7 @@
 package dotty.tools.dotc.core
 
 /** A collection of mode bits that are part of a context */
-case class Mode(val bits: Int) extends AnyVal {
+case class Mode(val bits: Int) extends AnyVal with EqClass[Mode] {
   import Mode._
   def | (that: Mode) = Mode(bits | that.bits)
   def & (that: Mode) = Mode(bits & that.bits)

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

@@ -52,7 +52,7 @@ object Periods {
    *
    *     // Dmitry: sign == 0 isn't actually always true, in some cases phaseId == -1 is used for shifts, that easily creates code < 0
    */
-  class Period(val code: Int) extends AnyVal {
+  class Period(val code: Int) extends AnyVal with EqClass[Period] {
 
     /** The run identifier of this period. */
     def runId: RunId = code >>> (PhaseWidth * 2)

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

@@ -261,7 +261,7 @@ object Phases {
     def isAfterTyper(phase: Phase): Boolean = phase.id > typerPhase.id
   }
 
-  trait Phase extends DotClass {
+  trait Phase extends DotClass with EqClass[Phase] {
 
     def phaseName: String
 

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

@@ -23,7 +23,7 @@ import TypeErasure.sigName
  *
  *  The signatures of non-method types are always `NotAMethod`.
  */
-case class Signature(paramsSig: List[TypeName], resSig: TypeName) {
+case class Signature(paramsSig: List[TypeName], resSig: TypeName) extends EqClass[Signature] {
   import Signature._
 
   /** Does this signature coincide with that signature on their parameter parts? */

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

@@ -12,7 +12,7 @@ import printing.Texts._
 import config.Config
 import collection.mutable
 
-class TyperState(r: Reporter) extends DotClass with Showable {
+class TyperState(r: Reporter) extends DotClass with Showable with EqClass[TyperState] {
 
   /** The current reporter */
   def reporter = r

src/dotty/tools/dotc/util/Positions.scala

@@ -30,7 +30,7 @@ object Positions {
    *  is roughly where the ^ would go if an error was diagnosed at that position.
    *  All quantities are encoded opaquely in a Long.
    */
-  class Position(val coords: Long) extends AnyVal {
+  class Position(val coords: Long) extends AnyVal with EqClass[Position] {
 
     /** Is this position different from NoPosition? */
     def exists = this != NoPosition

src/dotty/tools/dotc/util/SourceFile.scala

@@ -34,7 +34,7 @@ object ScriptSourceFile {
   }
 }
 
-case class SourceFile(file: AbstractFile, content: Array[Char]) extends interfaces.SourceFile {
+case class SourceFile(file: AbstractFile, content: Array[Char]) extends interfaces.SourceFile with EqClass[SourceFile] {
 
   def this(_file: AbstractFile)                 = this(_file, _file.toCharArray)
   def this(sourceName: String, cs: Seq[Char])   = this(new VirtualFile(sourceName), cs.toArray)

src/dotty/tools/dotc/util/SourcePosition.scala

@@ -5,7 +5,7 @@ package util
 import Positions.{Position, NoPosition}
 
 /** A source position is comprised of a position in a source file */
-case class SourcePosition(source: SourceFile, pos: Position) extends interfaces.SourcePosition {
+case class SourcePosition(source: SourceFile, pos: Position) extends interfaces.SourcePosition with EqClass[SourcePosition] {
   def exists = pos.exists
 
   def lineContent: String = source.lineContent(point)