Properly display value of value class in repl

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

@@ -37,7 +37,7 @@ class ReplPrinter(_ctx: Context) extends RefinedPrinter(_ctx) {
       if (sym.is(Method)) {
         sym.info match {
           case tp: ExprType => ":" ~~ toText(tp.resType)
-          case _ => toText(sym.info)
+          case info => toText(info)
         }
       }
       else if (sym.isType && sym.info.isTypeAlias) toText(sym.info)

compiler/src/dotty/tools/repl/Rendering.scala

@@ -106,11 +106,17 @@ private[repl] class Rendering(parentClassLoader: Option[ClassLoader] = None) {
       resObj
         .getDeclaredMethods.find(_.getName == sym.name.encode.toString)
         .map(_.invoke(null))
-    val string = value.map(replStringOf(_))
+
+    val resultSym = sym.info.classSymbol
+    val valueString = if (resultSym.isValueClass && !resultSym.isPrimitiveValueClass) then
+      value.map(value => s"${sym.info.classSymbol.name}@${value.hashCode.toHexString}")
+    else
+      value.map(replStringOf(_))
+
     if (!sym.is(Flags.Method) && sym.info == defn.UnitType)
       None
     else
-      string.map { s =>
+      valueString.map { s =>
         if (s.startsWith(REPL_WRAPPER_NAME_PREFIX))
           s.drop(REPL_WRAPPER_NAME_PREFIX.length).dropWhile(c => c.isDigit || c == '$')
         else

compiler/test-resources/repl/i15493

@@ -0,0 +1,107 @@
+scala> class NInt(val x: Int) extends AnyVal
+// defined class NInt
+
+scala> NInt(23)
+val res0: NInt = NInt@17
+
+scala> res0.toString
+val res1: String = NInt@17
+
+scala> 23
+val res2: Int = 23
+
+scala> class NBoolean(val x: Boolean) extends AnyVal
+// defined class NBoolean
+
+scala> NBoolean(true)
+val res3: NBoolean = NBoolean@4cf
+
+scala> res3.toString
+val res4: String = NBoolean@4cf
+
+scala> true
+val res5: Boolean = true
+
+scala> class NByte(val x: Byte) extends AnyVal
+// defined class NByte
+
+scala> NByte(1)
+val res6: NByte = NByte@1
+
+scala> res6.toString
+val res7: String = NByte@1
+
+scala> val res8: Byte = 1
+val res8: Byte = 1
+
+scala> class NShort(val x: Short) extends AnyVal
+// defined class NShort
+
+scala> NShort(1)
+val res9: NShort = NShort@1
+
+scala> res9.toString
+val res10: String = NShort@1
+
+scala> val res11: Short = 1
+val res11: Short = 1
+
+scala> class NLong(val x: Long) extends AnyVal
+// defined class NLong
+
+scala> NLong(1)
+val res12: NLong = NLong@1
+
+scala> res12.toString
+val res13: String = NLong@1
+
+scala> 1L
+val res14: Long = 1
+
+scala> class NFloat(val x: Float) extends AnyVal
+// defined class NFloat
+
+scala> NFloat(1L)
+val res15: NFloat = NFloat@3f800000
+
+scala> res15.toString
+val res16: String = NFloat@3f800000
+
+scala> 1.0F
+val res17: Float = 1.0
+
+scala> class NDouble(val x: Double) extends AnyVal
+// defined class NDouble
+
+scala> NDouble(1D)
+val res18: NDouble = NDouble@3ff00000
+
+scala> res18.toString
+val res19: String = NDouble@3ff00000
+
+scala> 1.0D
+val res20: Double = 1.0
+
+scala> class NChar(val x: Char) extends AnyVal
+// defined class NChar
+
+scala> NChar('a')
+val res21: NChar = NChar@61
+
+scala> res21.toString
+val res22: String = NChar@61
+
+scala> 'a'
+val res23: Char = a
+
+scala> class NString(val x: String) extends AnyVal
+// defined class NString
+
+scala> NString("test")
+val res24: NString = NString@364492
+
+scala> res24.toString
+val res25: String = NString@364492
+
+scala> "test"
+val res26: String = test