Fix tags in quoted.Type

Author: nicolasstucki

compiler/src/dotty/tools/dotc/core/quoted/PickledQuotes.scala

@@ -12,6 +12,8 @@ import dotty.tools.dotc.core.Symbols._
 import dotty.tools.dotc.core.tasty.{TastyPickler, TastyPrinter, TastyString}
 import dotty.tools.dotc.interpreter.RawQuoted
 
+import scala.reflect.ClassTag
+
 object PickledQuotes {
   import tpd._
 
@@ -33,6 +35,18 @@ object PickledQuotes {
   def quotedToTree(expr: quoted.Quoted)(implicit ctx: Context): Tree = expr match {
     case expr: quoted.TastyQuoted => unpickleQuote(expr)
     case expr: quoted.Liftable.ConstantExpr[_] => Literal(Constant(expr.value))
+    case expr: quoted.Type.TaggedPrimitive[_] =>
+      val tpe = expr.ct match {
+        case ClassTag.Unit => defn.UnitType
+        case ClassTag.Byte => defn.ByteType
+        case ClassTag.Char => defn.CharType
+        case ClassTag.Short => defn.ShortType
+        case ClassTag.Int => defn.IntType
+        case ClassTag.Long => defn.LongType
+        case ClassTag.Float => defn.FloatType
+        case ClassTag.Double => defn.FloatType
+      }
+      TypeTree(tpe)
     case expr: RawQuoted => expr.tree
   }
 

library/src/scala/quoted/Type.scala

@@ -1,11 +1,23 @@
 package scala.quoted
 
+import scala.reflect.ClassTag
+
 class Type[T] extends Quoted {
   type unary_~ = T
 }
 
 /** Some basic type tags, currently incomplete */
 object Type {
-  implicit def IntTag: Type[Int] = new Type[Int]
-  implicit def BooleanTag: Type[Boolean] = new Type[Boolean]
+
+  class TaggedPrimitive[T] private[Type] (implicit val ct: ClassTag[T]) extends Type[T]
+
+  implicit def UnitTag: Type[Unit] = new TaggedPrimitive[Unit]
+  implicit def BooleanTag: Type[Boolean] = new TaggedPrimitive[Boolean]
+  implicit def ByteTag: Type[Byte] = new TaggedPrimitive[Byte]
+  implicit def CharTag: Type[Char] = new TaggedPrimitive[Char]
+  implicit def ShortTag: Type[Short] = new TaggedPrimitive[Short]
+  implicit def IntTag: Type[Int] = new TaggedPrimitive[Int]
+  implicit def LongTag: Type[Long] = new TaggedPrimitive[Long]
+  implicit def FloatTag: Type[Float] = new TaggedPrimitive[Float]
+  implicit def DoubleTag: Type[Double] = new TaggedPrimitive[Double]
 }

tests/run-with-compiler/i3823-b.check

@@ -0,0 +1,4 @@
+{
+  val z: Int = 2
+  ()
+}

tests/run-with-compiler/i3823-b.scala

@@ -0,0 +1,10 @@
+import dotty.tools.dotc.quoted.Runners._
+import scala.quoted._
+object Test {
+  def main(args: Array[String]): Unit = {
+    def f[T](x: Expr[T])(t: Type[T]) = '{
+      val z: t.unary_~ = ~x
+    }
+    println(f('(2))(Type.IntTag).show)
+  }
+}