TypeErasure: Rename wildcardOK to inSigName

Its meaning was expanded in the previous commit.

Author: smarter

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

@@ -172,9 +172,9 @@ object TypeErasure {
     }
   }
 
-  private def erasureIdx(sourceLanguage: SourceLanguage, semiEraseVCs: Boolean, isConstructor: Boolean, isSymbol: Boolean, wildcardOK: Boolean) =
+  private def erasureIdx(sourceLanguage: SourceLanguage, semiEraseVCs: Boolean, isConstructor: Boolean, isSymbol: Boolean, inSigName: Boolean) =
     extension (b: Boolean) def toInt = if b then 1 else 0
-    wildcardOK.toInt
+    inSigName.toInt
     + (isSymbol.toInt         << 1)
     + (isConstructor.toInt    << 2)
     + (semiEraseVCs.toInt     << 3)
@@ -187,16 +187,16 @@ object TypeErasure {
     semiEraseVCs <- List(false, true)
     isConstructor <- List(false, true)
     isSymbol <- List(false, true)
-    wildcardOK <- List(false, true)
+    inSigName <- List(false, true)
   do
-    erasures(erasureIdx(sourceLanguage, semiEraseVCs, isConstructor, isSymbol, wildcardOK)) =
-      new TypeErasure(sourceLanguage, semiEraseVCs, isConstructor, isSymbol, wildcardOK)
+    erasures(erasureIdx(sourceLanguage, semiEraseVCs, isConstructor, isSymbol, inSigName)) =
+      new TypeErasure(sourceLanguage, semiEraseVCs, isConstructor, isSymbol, inSigName)
 
   /** Produces an erasure function. See the documentation of the class [[TypeErasure]]
    *  for a description of each parameter.
    */
-  private def erasureFn(sourceLanguage: SourceLanguage, semiEraseVCs: Boolean, isConstructor: Boolean, isSymbol: Boolean, wildcardOK: Boolean): TypeErasure =
-    erasures(erasureIdx(sourceLanguage, semiEraseVCs, isConstructor, isSymbol, wildcardOK))
+  private def erasureFn(sourceLanguage: SourceLanguage, semiEraseVCs: Boolean, isConstructor: Boolean, isSymbol: Boolean, inSigName: Boolean): TypeErasure =
+    erasures(erasureIdx(sourceLanguage, semiEraseVCs, isConstructor, isSymbol, inSigName))
 
   /** The current context with a phase no later than erasure */
   def preErasureCtx(using Context) =
@@ -207,19 +207,19 @@ object TypeErasure {
    *  @param tp            The type to erase.
   */
   def erasure(tp: Type)(using Context): Type =
-    erasureFn(sourceLanguage = SourceLanguage.Scala3, semiEraseVCs = false, isConstructor = false, isSymbol = false, wildcardOK = false)(tp)(using preErasureCtx).nn
+    erasureFn(sourceLanguage = SourceLanguage.Scala3, semiEraseVCs = false, isConstructor = false, isSymbol = false, inSigName = false)(tp)(using preErasureCtx).nn
 
   /** The value class erasure of a Scala type, where value classes are semi-erased to
    *  ErasedValueType (they will be fully erased in [[ElimErasedValueType]]).
    *
    *  @param tp            The type to erase.
    */
   def valueErasure(tp: Type)(using Context): Type =
-    erasureFn(sourceLanguage = SourceLanguage.Scala3, semiEraseVCs = true, isConstructor = false, isSymbol = false, wildcardOK = false)(tp)(using preErasureCtx).nn
+    erasureFn(sourceLanguage = SourceLanguage.Scala3, semiEraseVCs = true, isConstructor = false, isSymbol = false, inSigName = false)(tp)(using preErasureCtx).nn
 
   /** The erasure that Scala 2 would use for this type. */
   def scala2Erasure(tp: Type)(using Context): Type =
-    erasureFn(sourceLanguage = SourceLanguage.Scala2, semiEraseVCs = true, isConstructor = false, isSymbol = false, wildcardOK = false)(tp)(using preErasureCtx).nn
+    erasureFn(sourceLanguage = SourceLanguage.Scala2, semiEraseVCs = true, isConstructor = false, isSymbol = false, inSigName = false)(tp)(using preErasureCtx).nn
 
   /** Like value class erasure, but value classes erase to their underlying type erasure */
   def fullErasure(tp: Type)(using Context): Type =
@@ -229,7 +229,7 @@ object TypeErasure {
 
   def sigName(tp: Type, sourceLanguage: SourceLanguage)(using Context): TypeName = {
     val normTp = tp.translateFromRepeated(toArray = sourceLanguage.isJava)
-    val erase = erasureFn(sourceLanguage, semiEraseVCs = !sourceLanguage.isJava, isConstructor = false, isSymbol = false, wildcardOK = true)
+    val erase = erasureFn(sourceLanguage, semiEraseVCs = !sourceLanguage.isJava, isConstructor = false, isSymbol = false, inSigName = true)
     erase.sigName(normTp)(using preErasureCtx)
   }
 
@@ -259,7 +259,7 @@ object TypeErasure {
   def transformInfo(sym: Symbol, tp: Type)(using Context): Type = {
     val sourceLanguage = SourceLanguage(sym)
     val semiEraseVCs = !sourceLanguage.isJava // Java sees our value classes as regular classes.
-    val erase = erasureFn(sourceLanguage, semiEraseVCs, sym.isConstructor, isSymbol = true, wildcardOK = false)
+    val erase = erasureFn(sourceLanguage, semiEraseVCs, sym.isConstructor, isSymbol = true, inSigName = false)
 
     def eraseParamBounds(tp: PolyType): Type =
       tp.derivedLambdaType(
@@ -585,10 +585,10 @@ import TypeErasure._
  *                        If false, they are erased like normal classes.
  *  @param isConstructor  Argument forms part of the type of a constructor
  *  @param isSymbol       If true, the type being erased is the info of a symbol.
- *  @param wildcardOK     Wildcards and uninstantiated type variables are valid input
- *                        (only set to true by `TypeErasure.sigName`)
+ *  @param inSigName      This eraser is used for `TypeErasure.sigName`,
+ *                        see `TypeErasure#apply` for more information.
  */
-class TypeErasure(sourceLanguage: SourceLanguage, semiEraseVCs: Boolean, isConstructor: Boolean, isSymbol: Boolean, wildcardOK: Boolean) {
+class TypeErasure(sourceLanguage: SourceLanguage, semiEraseVCs: Boolean, isConstructor: Boolean, isSymbol: Boolean, inSigName: Boolean) {
 
   /**  The erasure |T| of a type T. 
    *
@@ -661,7 +661,7 @@ class TypeErasure(sourceLanguage: SourceLanguage, semiEraseVCs: Boolean, isConst
     case RefinedType(parent, nme.apply, refinedInfo: MethodType) if defn.isErasedFunctionType(parent) =>
       eraseErasedFunctionApply(refinedInfo)
     case tp: TypeVar if !tp.inst.exists =>
-      assert(wildcardOK, i"Cannot erase non-permanently instantiated type variable $tp")
+      assert(inSigName, i"Cannot erase non-permanently instantiated type variable $tp")
       null
     case tp: TypeProxy =>
       this(tp.underlying)
@@ -694,7 +694,7 @@ class TypeErasure(sourceLanguage: SourceLanguage, semiEraseVCs: Boolean, isConst
         else TypeComparer.orType(e1, e2, isErased = true)
     case tp: MethodType =>
       def paramErasure(tpToErase: Type) =
-        erasureFn(sourceLanguage, semiEraseVCs, isConstructor, isSymbol, wildcardOK = false)(tpToErase).nn
+        erasureFn(sourceLanguage, semiEraseVCs, isConstructor, isSymbol, inSigName = false)(tpToErase).nn
       val (names, formals0) = if tp.hasErasedParams then
         tp.paramNames
           .zip(tp.paramInfos)
@@ -747,11 +747,11 @@ class TypeErasure(sourceLanguage: SourceLanguage, semiEraseVCs: Boolean, isConst
     case _: ErrorType | JavaArrayType(_) =>
       tp
     case tp: WildcardType =>
-      assert(wildcardOK, i"Cannot erase wildcard type $tp")
+      assert(inSigName, i"Cannot erase wildcard type $tp")
       null
     case tp if (tp `eq` NoType) || (tp `eq` NoPrefix) => // Why is this check different?
       tp
-  ).ensuring(etp => etp != null || wildcardOK)
+  ).ensuring(etp => etp != null || inSigName)
 
   /** Like translucentSuperType, but issue a fatal error if it does not exist. */
   private def checkedSuperType(tp: TypeProxy)(using Context): Type =
@@ -783,7 +783,7 @@ class TypeErasure(sourceLanguage: SourceLanguage, semiEraseVCs: Boolean, isConst
     if (isGenericArrayElement(elemtp, isScala2 = sourceLanguage.isScala2)) defn.ObjectType
     else
       try
-        val eElem = erasureFn(sourceLanguage, semiEraseVCs = false, isConstructor, isSymbol, wildcardOK)(elemtp)
+        val eElem = erasureFn(sourceLanguage, semiEraseVCs = false, isConstructor, isSymbol, inSigName)(elemtp)
         if eElem == null then null
         else JavaArrayType(eElem)
       catch case ex: Throwable =>
@@ -805,7 +805,7 @@ class TypeErasure(sourceLanguage: SourceLanguage, semiEraseVCs: Boolean, isConst
    *  to the underlying type.
    */
   def eraseInfo(tp: Type, sym: Symbol)(using Context): Type =
-    assert(!wildcardOK) // therefore apply(...).nn won't fail
+    assert(!inSigName) // therefore apply(...).nn won't fail
     val tp1 = tp match
       case tp: MethodicType => integrateContextResults(tp, contextResultCount(sym))
       case _ => tp
@@ -833,7 +833,7 @@ class TypeErasure(sourceLanguage: SourceLanguage, semiEraseVCs: Boolean, isConst
       val underlying = tp.select(unbox).widen.resultType
 
       // The underlying part of an ErasedValueType cannot be an ErasedValueType itself
-      val erase = erasureFn(sourceLanguage, semiEraseVCs = false, isConstructor, isSymbol, wildcardOK)
+      val erase = erasureFn(sourceLanguage, semiEraseVCs = false, isConstructor, isSymbol, inSigName)
       val erasedUnderlying = erase(underlying)
       if erasedUnderlying == null then return null
 
@@ -869,12 +869,12 @@ class TypeErasure(sourceLanguage: SourceLanguage, semiEraseVCs: Boolean, isConst
 
   /** The erasure of a function result type. */
   def eraseResult(tp: Type)(using Context): Type =
-    assert(!wildcardOK) // therefore apply(...).nn won't fail
+    assert(!inSigName) // therefore apply(...).nn won't fail
     // For a value class V, "new V(x)" should have type V for type adaptation to work
     // correctly (see SIP-15 and [[Erasure.Boxing.adaptToType]]), so the result type of a
     // constructor method should not be semi-erased.
     if semiEraseVCs && isConstructor && !tp.isInstanceOf[MethodOrPoly] then
-      erasureFn(sourceLanguage, semiEraseVCs = false, isConstructor, isSymbol, wildcardOK).eraseResult(tp)
+      erasureFn(sourceLanguage, semiEraseVCs = false, isConstructor, isSymbol, inSigName).eraseResult(tp)
     else tp match
       case tp: TypeRef =>
         val sym = tp.symbol