Merge pull request #3241 from dotty-staging/private-this-var

Replace `private var` by `private[this] var` where possible

Author: smarter

compiler/sjs/backend/sjs/JSCodeGen.scala

@@ -72,7 +72,7 @@ class JSCodeGen()(implicit ctx: Context) {
   /* See genSuperCall()
    * TODO Can we avoid this unscoped var?
    */
-  private var isModuleInitialized: Boolean = false
+  private[this] var isModuleInitialized: Boolean = false
 
   private def currentClassType = encodeClassType(currentClassSym)
 

compiler/sjs/backend/sjs/ScopedVar.scala

@@ -5,7 +5,7 @@ import language.implicitConversions
 class ScopedVar[A](init: A) {
   import ScopedVar.Assignment
 
-  private var value = init
+  private[this] var value = init
 
   def this()(implicit ev: Null <:< A) = this(ev(null))
 

compiler/src/dotty/tools/backend/jvm/GenBCode.scala

@@ -77,9 +77,9 @@ class GenBCodePipeline(val entryPoints: List[Symbol], val int: DottyBackendInter
 
 //  class BCodePhase() {
 
-    private var bytecodeWriter  : BytecodeWriter   = null
-    private var mirrorCodeGen   : JMirrorBuilder   = null
-    private var beanInfoCodeGen : JBeanInfoBuilder = null
+    private[this] var bytecodeWriter  : BytecodeWriter   = null
+    private[this] var mirrorCodeGen   : JMirrorBuilder   = null
+    private[this] var beanInfoCodeGen : JBeanInfoBuilder = null
 
     /* ---------------- q1 ---------------- */
 

compiler/src/dotty/tools/dotc/Bench.scala

@@ -10,7 +10,7 @@ import reporting.Reporter
  */
 object Bench extends Driver {
 
-  @sharable private var numRuns = 1
+  @sharable private[this] var numRuns = 1
 
   private def ntimes(n: Int)(op: => Reporter): Reporter =
     (emptyReporter /: (0 until n)) ((_, _) => op)

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

@@ -33,7 +33,7 @@ object Trees {
   /** Property key for trees with documentation strings attached */
   val DocComment = new Property.Key[Comment]
 
-  @sharable private var nextId = 0 // for debugging
+  @sharable private[this] var nextId = 0 // for debugging
 
   type LazyTree = AnyRef     /* really: Tree | Lazy[Tree] */
   type LazyTreeList = AnyRef /* really: List[Tree] | Lazy[List[Tree]] */

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

@@ -209,7 +209,7 @@ object untpd extends Trees.Instance[Untyped] with UntypedTreeInfo {
    */
   abstract class DerivedTypeTree extends TypeTree {
 
-    private var myWatched: Tree = EmptyTree
+    private[this] var myWatched: Tree = EmptyTree
 
     /** The watched tree; used only for printing */
     def watched: Tree = myWatched

compiler/src/dotty/tools/dotc/config/JavaPlatform.scala

@@ -11,7 +11,7 @@ import transform.ExplicitOuter, transform.SymUtils._
 
 class JavaPlatform extends Platform {
 
-  private var currentClassPath: Option[ClassPath] = None
+  private[this] var currentClassPath: Option[ClassPath] = None
 
   def classPath(implicit ctx: Context): ClassPath = {
     if (currentClassPath.isEmpty)

compiler/src/dotty/tools/dotc/config/OutputDirs.scala

@@ -12,12 +12,12 @@ import io._
  */
 class OutputDirs {
   /** Pairs of source directory - destination directory. */
-  private var outputDirs: List[(AbstractFile, AbstractFile)] = Nil
+  private[this] var outputDirs: List[(AbstractFile, AbstractFile)] = Nil
 
   /** If this is not None, the output location where all
    *  classes should go.
    */
-  private var singleOutDir: Option[AbstractFile] = None
+  private[this] var singleOutDir: Option[AbstractFile] = None
 
   /** Add a destination directory for sources found under srcdir.
    *  Both directories should exits.

compiler/src/dotty/tools/dotc/config/Settings.scala

@@ -25,8 +25,8 @@ object Settings {
   val DirectoryTag = ClassTag(classOf[Directory])
 
   class SettingsState(initialValues: Seq[Any]) {
-    private var values = ArrayBuffer(initialValues: _*)
-    private var _wasRead: Boolean = false
+    private[this] var values = ArrayBuffer(initialValues: _*)
+    private[this] var _wasRead: Boolean = false
 
     override def toString = s"SettingsState(values: ${values.toList})"
 
@@ -68,7 +68,7 @@ object Settings {
     depends: List[(Setting[_], Any)] = Nil,
     propertyClass: Option[Class[_]] = None)(private[Settings] val idx: Int) {
 
-    private var changed: Boolean = false
+    private[this] var changed: Boolean = false
 
     def withAbbreviation(abbrv: String): Setting[T] =
       copy(aliases = aliases :+ abbrv)(idx)

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

@@ -38,7 +38,7 @@ object Annotations {
     override def symbol(implicit ctx: Context): Symbol
     def complete(implicit ctx: Context): Tree
 
-    private var myTree: Tree = null
+    private[this] var myTree: Tree = null
     def tree(implicit ctx: Context) = {
       if (myTree == null) myTree = complete(ctx)
       myTree
@@ -62,8 +62,8 @@ object Annotations {
   }
 
   case class LazyBodyAnnotation(private var bodyExpr: Context => Tree) extends BodyAnnotation {
-    private var evaluated = false
-    private var myBody: Tree = _
+    private[this] var evaluated = false
+    private[this] var myBody: Tree = _
     def tree(implicit ctx: Context) = {
       if (evaluated) assert(myBody != null)
       else {

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

@@ -30,7 +30,7 @@ trait ConstraintHandling {
   val state: TyperState
   import state.constraint
 
-  private var addConstraintInvocations = 0
+  private[this] var addConstraintInvocations = 0
 
   /** If the constraint is frozen we cannot add new bounds to the constraint. */
   protected var frozenConstraint = false

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

@@ -5,8 +5,8 @@ import Contexts._
 import config.Printers.typr
 
 trait ConstraintRunInfo { self: RunInfo =>
-  private var maxSize = 0
-  private var maxConstraint: Constraint = _
+  private[this] var maxSize = 0
+  private[this] var maxConstraint: Constraint = _
   def recordConstraintSize(c: Constraint, size: Int) =
     if (size > maxSize) {
       maxSize = size

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

@@ -160,12 +160,12 @@ object Contexts {
     /** An optional diagostics buffer than is used by some checking code
      *  to provide more information in the buffer if it exists.
      */
-    private var _diagnostics: Option[StringBuilder] = _
+    private[this] var _diagnostics: Option[StringBuilder] = _
     protected def diagnostics_=(diagnostics: Option[StringBuilder]) = _diagnostics = diagnostics
     def diagnostics: Option[StringBuilder] = _diagnostics
 
     /** The current bounds in force for type parameters appearing in a GADT */
-    private var _gadt: GADTMap = _
+    private[this] var _gadt: GADTMap = _
     protected def gadt_=(gadt: GADTMap) = _gadt = gadt
     def gadt: GADTMap = _gadt
 
@@ -175,14 +175,14 @@ object Contexts {
     def freshNames: FreshNameCreator = _freshNames
 
     /** A map in which more contextual properties can be stored */
-    private var _moreProperties: Map[Key[Any], Any] = _
+    private[this] var _moreProperties: Map[Key[Any], Any] = _
     protected def moreProperties_=(moreProperties: Map[Key[Any], Any]) = _moreProperties = moreProperties
     def moreProperties: Map[Key[Any], Any] = _moreProperties
 
     def property[T](key: Key[T]): Option[T] =
       moreProperties.get(key).asInstanceOf[Option[T]]
 
-    private var _typeComparer: TypeComparer = _
+    private[this] var _typeComparer: TypeComparer = _
     protected def typeComparer_=(typeComparer: TypeComparer) = _typeComparer = typeComparer
     def typeComparer: TypeComparer = {
       if (_typeComparer.ctx ne this)
@@ -224,7 +224,7 @@ object Contexts {
     }
 
     /** The history of implicit searches that are currently active */
-    private var _searchHistory: SearchHistory = null
+    private[this] var _searchHistory: SearchHistory = null
     protected def searchHistory_= (searchHistory: SearchHistory) = _searchHistory = searchHistory
     def searchHistory: SearchHistory = _searchHistory
 
@@ -233,8 +233,8 @@ object Contexts {
       * phasedCtxs is array that uses phaseId's as indexes,
       * contexts are created only on request and cached in this array
       */
-    private var phasedCtx: Context = _
-    private var phasedCtxs: Array[Context] = _
+    private[this] var phasedCtx: Context = _
+    private[this] var phasedCtxs: Array[Context] = _
 
     /** This context at given phase.
      *  This method will always return a phase period equal to phaseId, thus will never return squashed phases
@@ -268,7 +268,7 @@ object Contexts {
     /** If -Ydebug is on, the top of the stack trace where this context
      *  was created, otherwise `null`.
      */
-    private var creationTrace: Array[StackTraceElement] = _
+    private[this] var creationTrace: Array[StackTraceElement] = _
 
     private def setCreationTrace() =
       if (this.settings.YtraceContextCreation.value)
@@ -393,7 +393,7 @@ object Contexts {
 
     /** A condensed context containing essential information of this but
      *  no outer contexts except the initial context.
-    private var _condensed: CondensedContext = null
+    private[this] var _condensed: CondensedContext = null
     def condensed: CondensedContext = {
       if (_condensed eq outer.condensed)
         _condensed = base.initialCtx.fresh
@@ -557,7 +557,7 @@ object Contexts {
     val loaders = new SymbolLoaders
 
     /** The platform, initialized by `initPlatform()`. */
-    private var _platform: Platform = _
+    private[this] var _platform: Platform = _
 
     /** The platform */
     def platform: Platform = {
@@ -670,7 +670,7 @@ object Contexts {
     // Test that access is single threaded
 
     /** The thread on which `checkSingleThreaded was invoked last */
-    @sharable private var thread: Thread = null
+    @sharable private[this] var thread: Thread = null
 
     /** Check that we are on the same thread as before */
     def checkSingleThreaded() =
@@ -695,7 +695,7 @@ object Contexts {
   }
 
   class GADTMap(initBounds: SimpleIdentityMap[Symbol, TypeBounds]) extends util.DotClass {
-    private var myBounds = initBounds
+    private[this] var myBounds = initBounds
     def setBounds(sym: Symbol, b: TypeBounds): Unit =
       myBounds = myBounds.updated(sym, b)
     def bounds = myBounds

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

@@ -950,8 +950,8 @@ class Definitions {
 
   /** This class would also be obviated by the implicit function type design */
   class PerRun[T](generate: Context => T) {
-    private var current: RunId = NoRunId
-    private var cached: T = _
+    private[this] var current: RunId = NoRunId
+    private[this] var cached: T = _
     def apply()(implicit ctx: Context): T = {
       if (current != ctx.runId) {
         cached = generate(ctx)

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

@@ -1122,9 +1122,9 @@ object Denotations {
      */
     def filterExcluded(excluded: FlagSet)(implicit ctx: Context): PreDenotation
 
-    private var cachedPrefix: Type = _
-    private var cachedAsSeenFrom: AsSeenFromResult = _
-    private var validAsSeenFrom: Period = Nowhere
+    private[this] var cachedPrefix: Type = _
+    private[this] var cachedAsSeenFrom: AsSeenFromResult = _
+    private[this] var validAsSeenFrom: Period = Nowhere
     type AsSeenFromResult <: PreDenotation
 
     /** The denotation with info(s) as seen from prefix type */

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

@@ -189,7 +189,7 @@ object Names {
     def underlying: TermName = unsupported("underlying")
 
     @sharable // because of synchronized block in `and`
-    private var derivedNames: AnyRef /* immutable.Map[NameInfo, DerivedName] | j.u.HashMap */ =
+    private[this] var derivedNames: AnyRef /* immutable.Map[NameInfo, DerivedName] | j.u.HashMap */ =
       immutable.Map.empty[NameInfo, DerivedName]
 
     private def getDerived(info: NameInfo): DerivedName /* | Null */= derivedNames match {
@@ -537,15 +537,15 @@ object Names {
 
   /** The number of characters filled. */
   @sharable // because it's only mutated in synchronized block of termName
-  private var nc = 0
+  private[this] var nc = 0
 
   /** Hashtable for finding term names quickly. */
   @sharable // because it's only mutated in synchronized block of termName
-  private var table = new Array[SimpleName](InitialHashSize)
+  private[this] var table = new Array[SimpleName](InitialHashSize)
 
   /** The number of defined names. */
   @sharable // because it's only mutated in synchronized block of termName
-  private var size = 1
+  private[this] var size = 1
 
   /** The hash of a name made of from characters cs[offset..offset+len-1].  */
   private def hashValue(cs: Array[Char], offset: Int, len: Int): Int =

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

@@ -544,7 +544,7 @@ class OrderingConstraint(private val boundsMap: ParamBounds,
     upperMap.foreachBinding((_, paramss) => paramss.foreach(_.foreach(checkClosedType(_, "upper"))))
   }
 
-  private var myUninstVars: mutable.ArrayBuffer[TypeVar] = _
+  private[this] var myUninstVars: mutable.ArrayBuffer[TypeVar] = _
 
   /** The uninstantiated typevars of this constraint */
   def uninstVars: collection.Seq[TypeVar] = {

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

@@ -318,16 +318,16 @@ object Phases {
 
     def exists: Boolean = true
 
-    private var myPeriod: Period = Periods.InvalidPeriod
-    private var myBase: ContextBase = null
-    private var myErasedTypes = false
-    private var myFlatClasses = false
-    private var myRefChecked = false
-    private var mySymbolicRefs = false
-    private var myLabelsReordered = false
-
-    private var mySameMembersStartId = NoPhaseId
-    private var mySameParentsStartId = NoPhaseId
+    private[this] var myPeriod: Period = Periods.InvalidPeriod
+    private[this] var myBase: ContextBase = null
+    private[this] var myErasedTypes = false
+    private[this] var myFlatClasses = false
+    private[this] var myRefChecked = false
+    private[this] var mySymbolicRefs = false
+    private[this] var myLabelsReordered = false
+
+    private[this] var mySameMembersStartId = NoPhaseId
+    private[this] var mySameParentsStartId = NoPhaseId
 
     /** The sequence position of this phase in the given context where 0
      * is reserved for NoPhase and the first real phase is at position 1.

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

@@ -210,11 +210,11 @@ object Scopes {
 
     /** the hash table
      */
-    private var hashTable: Array[ScopeEntry] = null
+    private[this] var hashTable: Array[ScopeEntry] = null
 
     /** a cache for all elements, to be used by symbol iterator.
      */
-    private var elemsCache: List[Symbol] = null
+    private[this] var elemsCache: List[Symbol] = null
 
     /** The synthesizer to be used, or `null` if no synthesis is done on this scope */
     private var synthesize: SymbolSynthesizer = null

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

@@ -1874,9 +1874,9 @@ object SymDenotations {
     def apply(sym: Symbol) = this
     def apply(module: TermSymbol, modcls: ClassSymbol) = this
 
-    private var myDecls: Scope = EmptyScope
-    private var mySourceModuleFn: Context => Symbol = NoSymbolFn
-    private var myModuleClassFn: Context => Symbol = NoSymbolFn
+    private[this] var myDecls: Scope = EmptyScope
+    private[this] var mySourceModuleFn: Context => Symbol = NoSymbolFn
+    private[this] var myModuleClassFn: Context => Symbol = NoSymbolFn
 
     /** A proxy to this lazy type that keeps the complete operation
      *  but provides fresh slots for scope/sourceModule/moduleClass
@@ -2046,7 +2046,7 @@ object SymDenotations {
     final def isValid(implicit ctx: Context): Boolean =
       cache != null && isValidAt(ctx.phase)
 
-    private var locked = false
+    private[this] var locked = false
 
     /** Computing parent member names might force parents, which could invalidate
      *  the cache itself. In that case we should cancel invalidation and
@@ -2144,9 +2144,9 @@ object SymDenotations {
 
   /** A class to combine base data from parent types */
   class BaseDataBuilder {
-    private var classes: List[ClassSymbol] = Nil
-    private var classIds = new Array[Int](32)
-    private var length = 0
+    private[this] var classes: List[ClassSymbol] = Nil
+    private[this] var classIds = new Array[Int](32)
+    private[this] var length = 0
 
     private def resize(size: Int) = {
       val classIds1 = new Array[Int](size)
@@ -2182,5 +2182,5 @@ object SymDenotations {
     def baseClasses: List[ClassSymbol] = classes
   }
 
-  @sharable private var indent = 0 // for completions printing
+  @sharable private[this] var indent = 0 // for completions printing
 }

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

@@ -150,7 +150,7 @@ class SymbolLoaders {
     override def sourceModule(implicit ctx: Context) = _sourceModule
     def description(implicit ctx: Context) = "package loader " + sourceModule.fullName
 
-    private var enterFlatClasses: Option[Context => Unit] = None
+    private[this] var enterFlatClasses: Option[Context => Unit] = None
 
     Stats.record("package scopes")