Print and highlight erased arguments

Author: OlivierBlanvillain

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

@@ -169,7 +169,9 @@ class PlainPrinter(_ctx: Context) extends Printer {
         "<noprefix>"
       case tp: MethodType =>
         changePrec(GlobalPrec) {
-          (if (tp.isImplicitMethod) "(implicit " else "(") ~ paramsText(tp) ~
+          ("(" + (if (tp.isImplicitMethod) "implicit " else "")
+               + (if (tp.isErasedMethod)   "erased "   else "")
+          ) ~ paramsText(tp) ~
           (if (tp.resultType.isInstanceOf[MethodType]) ")" else "): ") ~
           toText(tp.resultType)
         }

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

@@ -31,7 +31,7 @@ object SyntaxHighlighting {
   private val tripleQs = Console.RED_B + "???" + NoColor
 
   private val keywords: Seq[String] = for {
-    index <- IF to ENUM // All alpha keywords
+    index <- IF to ERASED // All alpha keywords
   } yield tokenString(index)
 
   private val interpolationPrefixes =

compiler/test-resources/repl/erased

@@ -0,0 +1,2 @@
+scala> def f(erased a: Int): Int = ???
+def f(erased a: Int): Int