Merge pull request #4677 from dotty-staging/add-Tasty-relect-LambdaTypeTree

Add TypeTree.TypeLambda to Tasty reflect

Author: nicolasstucki

compiler/src/dotty/tools/dotc/tastyreflect/TastyImpl.scala

@@ -606,6 +606,12 @@ object TastyImpl extends scala.tasty.Tasty {
       }
     }
 
+    object TypeLambdaTree extends TypeLambdaTreeExtractor {
+      def unapply(x: TypeTree)(implicit ctx: Context): Option[(List[TypeDef], TypeOrBoundsTree)] = x match {
+        case Trees.LambdaTypeTree(tparams, body) => Some((tparams, body))
+        case _ => None
+      }
+    }
   }
 
   // ----- TypeBoundsTrees ------------------------------------------------

library/src/scala/tasty/Tasty.scala

@@ -440,6 +440,10 @@ abstract class Tasty { tasty =>
       def unapply(x: TypeTree)(implicit ctx: Context): Option[TypeTree]
     }
 
+    val TypeLambdaTree: TypeLambdaTreeExtractor
+    abstract class TypeLambdaTreeExtractor {
+      def unapply(x: TypeTree)(implicit ctx: Context): Option[(List[TypeDef], TypeOrBoundsTree)]
+    }
   }
 
   // ----- TypeBoundsTrees ------------------------------------------------

library/src/scala/tasty/util/ShowExtractors.scala

@@ -110,6 +110,8 @@ class ShowExtractors[T <: Tasty with Singleton](tasty0: T) extends Show[T](tasty
         this += "TypeTree.ByName(" += result += ")"
       case TypeTree.Annotated(arg, annot) =>
         this += "TypeTree.Annotated(" += arg += ", " += annot += ")"
+      case TypeTree.TypeLambdaTree(tparams, body) =>
+        this += "LambdaTypeTree(" ++= tparams += ", " += body += ")"
       case TypeBoundsTree(lo, hi) =>
         this += "TypeBoundsTree(" += lo += ", " += hi += ")"
       case SyntheticBounds() =>
@@ -185,6 +187,8 @@ class ShowExtractors[T <: Tasty with Singleton](tasty0: T) extends Show[T](tasty
         this += "Type.ThisType(" += tp += ")"
       case Type.RecursiveThis(binder) =>
         this += "Type.RecursiveThis(" += binder += ")"
+      case Type.RecursiveType(underlying) =>
+        this += "Type.RecursiveType(" += underlying += ")"
       case Type.MethodType(argNames, argTypes, resType) =>
         this += "Type.MethodType(" ++= argNames += ", " ++= argTypes += ", " += resType += ")"
       case Type.PolyType(argNames, argBounds, resType) =>

library/src/scala/tasty/util/ShowSourceCode.scala

@@ -148,7 +148,7 @@ class ShowSourceCode[T <: Tasty with Singleton](tasty0: T) extends Show[T](tasty
 
       case tdef@TypeDef(name, rhs) =>
         this += "type "
-        printTargDef(tdef)
+        printTargDef(tdef, isMember = true)
 
       case vdef@ValDef(name, tpt, rhs) =>
         val flags = vdef.flags
@@ -469,7 +469,7 @@ class ShowSourceCode[T <: Tasty with Singleton](tasty0: T) extends Show[T](tasty
       }
     }
 
-    def printTargDef(arg: TypeDef): Buffer = {
+    def printTargDef(arg: TypeDef, isMember: Boolean = false): Buffer = {
       val TypeDef(name, rhs) = arg
       this += name
       rhs match {
@@ -488,6 +488,28 @@ class ShowSourceCode[T <: Tasty with Singleton](tasty0: T) extends Show[T](tasty
           }
         case rhs @ SyntheticBounds() =>
           printTypeOrBound(rhs.tpe)
+        case rhs @ TypeTree.TypeLambdaTree(tparams, body) =>
+          def printSeparated(list: List[TypeDef]): Unit = list match {
+            case Nil =>
+            case x :: Nil =>
+              val TypeDef(name, trhs) = x
+              this += name
+              printTypeOrBoundsTree(trhs)
+            case x :: xs =>
+              val TypeDef(name, trhs) = x
+              this += name
+              printTypeOrBoundsTree(trhs)
+              this += ", "
+              printSeparated(xs)
+          }
+          this += "["
+          printSeparated(tparams)
+          this += "]"
+          if (isMember) {
+            this += " = "
+            printTypeOrBoundsTree(body)
+          }
+          else this
         case rhs @ TypeTree() =>
           this += " = "
           printTypeTree(rhs)
@@ -672,6 +694,11 @@ class ShowSourceCode[T <: Tasty with Singleton](tasty0: T) extends Show[T](tasty
         this += "=> "
         printTypeTree(result)
 
+      case TypeTree.TypeLambdaTree(tparams, body) =>
+        printTargsDefs(tparams)
+        this += " => "
+        printTypeOrBoundsTree(body)
+
       case _ =>
         throw new MatchError(tree.show)
 
@@ -757,6 +784,30 @@ class ShowSourceCode[T <: Tasty with Singleton](tasty0: T) extends Show[T](tasty
           case _ => this
         }
 
+      case Type.TypeLambda(paramNames, tparams, body) =>
+        this += "["
+        def printSeparated(list: List[(String, TypeBounds)]): Unit = list match {
+          case Nil =>
+          case (name, bounds) :: Nil =>
+            this += name
+            printTypeOrBound(bounds)
+          case (name, bounds) :: xs =>
+            this += name
+            printTypeOrBound(bounds)
+            this += ", "
+            printSeparated(xs)
+        }
+        printSeparated(paramNames.zip(tparams))
+        this += "] => "
+        printTypeOrBound(body)
+
+      case Type.ParamRef(lambda, idx) =>
+        lambda match {
+          case Type.MethodType(params, _, _) => this += params(idx)
+          case Type.PolyType(params, _, _) => this += params(idx)
+          case Type.TypeLambda(params, _, _) => this += params(idx)
+        }
+
       case _ =>
         throw new MatchError(tpe.show)
     }

tests/pos/i1181.decompiled

@@ -0,0 +1,8 @@
+/** Decompiled from out/posTestFromTasty/pos/i1181/Test.class */
+object Test {
+  def foo[M[_$1 >: scala.Nothing <: scala.Any]](x: M[scala.Int]): M[scala.Int] = x
+  type Alias[A >: scala.Nothing <: scala.Any] = scala.Tuple2[A, A]
+  val x: Test.Alias[scala.Int] = scala.Tuple2.apply[scala.Int, scala.Int](1, 2)
+  Test.foo[Test.Alias](Test.x)
+  Test.foo[[A >: scala.Nothing <: scala.Any] => scala.Tuple2[A, A]](Test.x)
+}

tests/pos/tasty/definitions.scala

@@ -100,6 +100,7 @@ object definitions {
     case And(left: TypeTree, right: TypeTree)
     case Or(left: TypeTree, right: TypeTree)
     case ByName(tpt: TypeTree)
+    case TypeLambda(tparams: List[TypeDef], body: Type | TypeBoundsTree)
   }
 
   /** Trees denoting type bounds */