Refactor: Move allParamSyms to TreeInfo

Author: odersky

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

@@ -191,13 +191,9 @@ trait TreeInfo[T >: Untyped <: Type] { self: Trees.Instance[T] =>
     case arg => arg.typeOpt.widen.isRepeatedParam
   }
 
-  /** If this tree has type parameters, those.  Otherwise Nil.
-  def typeParameters(tree: Tree): List[TypeDef] = tree match {
-    case DefDef(_, _, tparams, _, _, _) => tparams
-    case ClassDef(_, _, tparams, _)     => tparams
-    case TypeDef(_, _, tparams, _)      => tparams
-    case _                              => Nil
-  }*/
+  /** All type and value parameter symbols of this DefDef */
+  def allParamSyms(ddef: DefDef)(using Context): List[Symbol] =
+    (ddef.tparams ::: ddef.vparamss.flatten).map(_.symbol)
 
   /** Does this argument list end with an argument of the form <expr> : _* ? */
   def isWildcardStarArgList(trees: List[Tree])(implicit ctx: Context): Boolean =

compiler/src/dotty/tools/dotc/transform/Erasure.scala

@@ -924,10 +924,8 @@ object Erasure {
       stats.mapConserve {
         case stat: DefDef if stat.symbol.isInlineMethod && stat.symbol.isInlineRetained =>
           val rdef = retainerDef(stat.symbol)
-          def allParams(ddef: DefDef) =
-            (ddef.tparams ::: ddef.vparamss.flatten).map(_.symbol)
-          val fromParams = allParams(rdef)
-          val toParams = allParams(stat)
+          val fromParams = untpd.allParamSyms(rdef)
+          val toParams = untpd.allParamSyms(stat)
           assert(fromParams.hasSameLengthAs(toParams))
           val mapBody = TreeTypeMap(
             oldOwners = rdef.symbol :: Nil,

compiler/src/dotty/tools/dotc/transform/HoistSuperArgs.scala

@@ -69,7 +69,7 @@ class HoistSuperArgs extends MiniPhase with IdentityDenotTransformer { thisPhase
         if (constr == cls.primaryConstructor)
           cls.info.decls.filter(d => d.is(TypeParam) || d.is(ParamAccessor))
         else
-          (cdef.tparams ::: cdef.vparamss.flatten).map(_.symbol)
+          allParamSyms(cdef)
 
       /** The parameter references defined by the constructor info */
       def allParamRefs(tp: Type): List[ParamRef] = tp match {