Move erasedParams into MethodType

Author: nicolasstucki

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

@@ -3721,8 +3721,6 @@ object Types {
 
     def companion: LambdaTypeCompanion[ThisName, PInfo, This]
 
-    def erasedParams(using Context) = List.fill(paramInfos.size)(false)
-
     /** The type `[tparams := paramRefs] tp`, where `tparams` can be
      *  either a list of type parameter symbols or a list of lambda parameters
      *
@@ -4019,7 +4017,7 @@ object Types {
     final override def isContextualMethod: Boolean =
       companion.eq(ContextualMethodType)
 
-    override def erasedParams(using Context): List[Boolean] =
+    def erasedParams(using Context): List[Boolean] =
       paramInfos.map(p => p.hasAnnotation(defn.ErasedParamAnnot))
 
     def nonErasedParamCount(using Context): Int =

compiler/src/dotty/tools/dotc/printing/PlainPrinter.scala

@@ -297,10 +297,10 @@ class PlainPrinter(_ctx: Context) extends Printer {
     "(" ~ toTextRef(tp) ~ " : " ~ toTextGlobal(tp.underlying) ~ ")"
 
   protected def paramsText(lam: LambdaType): Text = {
-    val erasedParams = lam.erasedParams
-    def paramText(ref: ParamRef, erased: Boolean) =
+    def paramText(ref: ParamRef) =
+      val erased = ref.underlying.hasAnnotation(defn.ErasedParamAnnot)
       keywordText("erased ").provided(erased) ~ ParamRefNameString(ref) ~ lambdaHash(lam) ~ toTextRHS(ref.underlying, isParameter = true)
-    Text(lam.paramRefs.lazyZip(erasedParams).map(paramText), ", ")
+    Text(lam.paramRefs.map(paramText), ", ")
   }
 
   protected def ParamRefNameString(name: Name): String = nameString(name)