Make sure captured types are listed before terms

compiler/src/dotty/tools/dotc/ast/TreeTypeMap.scala

@@ -146,11 +146,12 @@ class TreeTypeMap(
           val bind1 = tmap.transformSub(bind)
           val expr1 = tmap.transform(expr)
           cpy.Labeled(labeled)(bind1, expr1)
-        case tree @ Hole(_, _, args, content, tpt) =>
+        case tree @ Hole(_, _, targs, args, content, tpt) =>
+          val targs1 = targs.mapConserve(transform)
           val args1 = args.mapConserve(transform)
           val content1 = transform(content)
           val tpt1 = transform(tpt)
-          cpy.Hole(tree)(args = args1, content = content1, tpt = tpt1)
+          cpy.Hole(tree)(targs = targs1, args = args1, content = content1, tpt = tpt1)
         case tree1 =>
           super.transform(tree1)
       }

compiler/src/dotty/tools/dotc/ast/Trees.scala

@@ -976,20 +976,47 @@ object Trees {
   def genericEmptyTree[T <: Untyped]: Thicket[T]        = theEmptyTree.asInstanceOf[Thicket[T]]
 
   /** Tree that replaces a level 1 splices in pickled (level 0) quotes.
-   *  It is only used when picking quotes (will never be in a TASTy file).
+   *
+   *  It is only used when encoding pickled quotes. These will be encoded
+   *  as TastyQuoteHole when pickled. These holes will be inserted in the
+   *  Staging phase and pickled (without the content) as TASTy HOLE in the
+   *  PickleQuotes phase.
    *
    *  @param isTermHole If this hole is a term, otherwise it is a type hole.
    *  @param idx The index of the hole in it's enclosing level 0 quote.
-   *  @param args The arguments of the splice to compute its content
-   *  @param content Lambda that computes the content of the hole. This tree is empty when in a quote pickle.
+   *  @param targs The type arguments of the splice to compute its content
+   *  @param args The term (or type) arguments of the splice to compute its content
    *  @param tpt Type of the hole
+   *  @param content Lambda that computes the content of the hole. This tree is empty when in a quote pickle.
    */
-  case class Hole[+T <: Untyped](isTermHole: Boolean, idx: Int, args: List[Tree[T]], content: Tree[T], tpt: Tree[T])(implicit @constructorOnly src: SourceFile) extends Tree[T] {
+  case class Hole[+T <: Untyped](isTermHole: Boolean, idx: Int, targs: List[Tree[T]], args: List[Tree[T]], content: Tree[T], tpt: Tree[T])(implicit @constructorOnly src: SourceFile) extends Tree[T] {
     type ThisTree[+T <: Untyped] <: Hole[T]
     override def isTerm: Boolean = isTermHole
     override def isType: Boolean = !isTermHole
   }
 
+  /** Tree that replaces a level 1 splices in pickled (level 0) quotes.
+   *  It is only used when unpicking quotes TASTy HOLE. These holes will
+   *  only be present in pickled quotes. These are unpickled and replaced
+   *  with other trees in PickledQuotes.
+   *
+   *  Hole created by this compiler separate the targs from the args. Holes
+   *  generated with 3.0-3.3 contain all type args and targs in any order in
+   *  a single list. For backwards compatibility we read holes from tasty as
+   *  if they had no targs and have only args. Therefore the args may contain
+   *  type trees.
+   *
+   *  @param isTermHole If this hole is a term, otherwise it is a type hole.
+   *  @param idx The index of the hole in it's enclosing level 0 quote.
+   *  @param args The term (or type) arguments of the splice to compute its content
+   *  @param tpt Type of the hole
+   */
+  case class TastyQuoteHole[+T <: Untyped](isTermHole: Boolean, idx: Int, args: List[Tree[T]], tpt: Tree[T])(implicit @constructorOnly src: SourceFile) extends Tree[T] {
+    type ThisTree[+T <: Untyped] <: TastyQuoteHole[T]
+    override def isTerm: Boolean = isTermHole
+    override def isType: Boolean = !isTermHole
+  }
+
   def flatten[T <: Untyped](trees: List[Tree[T]]): List[Tree[T]] = {
     def recur(buf: ListBuffer[Tree[T]] | Null, remaining: List[Tree[T]]): ListBuffer[Tree[T]] | Null =
       remaining match {
@@ -1112,6 +1139,7 @@ object Trees {
     type Thicket = Trees.Thicket[T]
 
     type Hole = Trees.Hole[T]
+    type TastyQuoteHole = Trees.TastyQuoteHole[T]
 
     @sharable val EmptyTree: Thicket = genericEmptyTree
     @sharable val EmptyValDef: ValDef = genericEmptyValDef
@@ -1337,9 +1365,13 @@ object Trees {
         case tree: Thicket if (trees eq tree.trees) => tree
         case _ => finalize(tree, untpd.Thicket(trees)(sourceFile(tree)))
       }
-      def Hole(tree: Tree)(isTerm: Boolean, idx: Int, args: List[Tree], content: Tree, tpt: Tree)(using Context): Hole = tree match {
-        case tree: Hole if isTerm == tree.isTerm && idx == tree.idx && args.eq(tree.args) && content.eq(tree.content) && content.eq(tree.content) => tree
-        case _ => finalize(tree, untpd.Hole(isTerm, idx, args, content, tpt)(sourceFile(tree)))
+      def Hole(tree: Tree)(isTerm: Boolean, idx: Int, targs: List[Tree], args: List[Tree], content: Tree, tpt: Tree)(using Context): Hole = tree match {
+        case tree: Hole if isTerm == tree.isTerm && idx == tree.idx && targs.eq(tree.targs) && args.eq(tree.args) && content.eq(tree.content) && tpt.eq(tree.tpt) => tree
+        case _ => finalize(tree, untpd.Hole(isTerm, idx, targs, args, content, tpt)(sourceFile(tree)))
+      }
+      def TastyQuoteHole(tree: Tree)(isTerm: Boolean, idx: Int, args: List[Tree], tpt: Tree)(using Context): TastyQuoteHole = tree match {
+        case tree: TastyQuoteHole if isTerm == tree.isTerm && idx == tree.idx && args.eq(tree.args) && tpt.eq(tree.tpt) => tree
+        case _ => finalize(tree, untpd.TastyQuoteHole(isTerm, idx, args, tpt)(sourceFile(tree)))
       }
 
       // Copier methods with default arguments; these demand that the original tree
@@ -1362,8 +1394,10 @@ object Trees {
         TypeDef(tree: Tree)(name, rhs)
       def Template(tree: Template)(using Context)(constr: DefDef = tree.constr, parents: List[Tree] = tree.parents, derived: List[untpd.Tree] = tree.derived, self: ValDef = tree.self, body: LazyTreeList = tree.unforcedBody): Template =
         Template(tree: Tree)(constr, parents, derived, self, body)
-      def Hole(tree: Hole)(isTerm: Boolean = tree.isTerm, idx: Int = tree.idx, args: List[Tree] = tree.args, content: Tree = tree.content, tpt: Tree = tree.tpt)(using Context): Hole =
-        Hole(tree: Tree)(isTerm, idx, args, content, tpt)
+      def Hole(tree: Hole)(isTerm: Boolean = tree.isTerm, idx: Int = tree.idx, targs: List[Tree] = tree.targs, args: List[Tree] = tree.args, content: Tree = tree.content, tpt: Tree = tree.tpt)(using Context): Hole =
+        Hole(tree: Tree)(isTerm, idx, targs, args, content, tpt)
+      def TastyQuoteHole(tree: TastyQuoteHole)(isTerm: Boolean = tree.isTerm, idx: Int = tree.idx, args: List[Tree] = tree.args, tpt: Tree = tree.tpt)(using Context): TastyQuoteHole =
+        TastyQuoteHole(tree: Tree)(isTerm, idx, args, tpt)
 
     }
 
@@ -1494,8 +1528,10 @@ object Trees {
             case Thicket(trees) =>
               val trees1 = transform(trees)
               if (trees1 eq trees) tree else Thicket(trees1)
-            case tree @ Hole(_, _, args, content, tpt) =>
-              cpy.Hole(tree)(args = transform(args), content = transform(content), tpt = transform(tpt))
+            case tree @ Hole(_, _, targs, args, content, tpt) =>
+              cpy.Hole(tree)(targs = transform(targs), args = transform(args), content = transform(content), tpt = transform(tpt))
+            case tree @ TastyQuoteHole(_, _, args, tpt) =>
+              cpy.TastyQuoteHole(tree)(args = transform(args), tpt = transform(tpt))
             case _ =>
               transformMoreCases(tree)
           }
@@ -1635,8 +1671,10 @@ object Trees {
               this(this(x, arg), annot)
             case Thicket(ts) =>
               this(x, ts)
-            case Hole(_, _, args, content, tpt) =>
-              this(this(this(x, args), content), tpt)
+            case Hole(_, _, targs, args, content, tpt) =>
+              this(this(this(this(x, targs), args), content), tpt)
+            case TastyQuoteHole(_, _, args, tpt) =>
+              this(this(x, args), tpt)
             case _ =>
               foldMoreCases(x, tree)
           }

compiler/src/dotty/tools/dotc/ast/tpd.scala

@@ -391,8 +391,8 @@ object tpd extends Trees.Instance[Type] with TypedTreeInfo {
   def Throw(expr: Tree)(using Context): Tree =
     ref(defn.throwMethod).appliedTo(expr)
 
-  def Hole(isTermHole: Boolean, idx: Int, args: List[Tree], content: Tree, tpt: Tree)(using Context): Hole =
-    ta.assignType(untpd.Hole(isTermHole, idx, args, content, tpt), tpt)
+  def Hole(isTermHole: Boolean, idx: Int, targs: List[Tree], args: List[Tree], content: Tree, tpt: Tree)(using Context): Hole =
+    ta.assignType(untpd.Hole(isTermHole, idx, targs, args, content, tpt), tpt)
 
   // ------ Making references ------------------------------------------------------
 

compiler/src/dotty/tools/dotc/ast/untpd.scala

@@ -426,7 +426,8 @@ object untpd extends Trees.Instance[Untyped] with UntypedTreeInfo {
   def Export(expr: Tree, selectors: List[ImportSelector])(implicit src: SourceFile): Export = new Export(expr, selectors)
   def PackageDef(pid: RefTree, stats: List[Tree])(implicit src: SourceFile): PackageDef = new PackageDef(pid, stats)
   def Annotated(arg: Tree, annot: Tree)(implicit src: SourceFile): Annotated = new Annotated(arg, annot)
-  def Hole(isTermHole: Boolean, idx: Int, args: List[Tree], content: Tree, tpt: Tree)(implicit src: SourceFile): Hole = new Hole(isTermHole, idx, args, content, tpt)
+  def Hole(isTermHole: Boolean, idx: Int, targs: List[Tree], args: List[Tree], content: Tree, tpt: Tree)(implicit src: SourceFile): Hole = new Hole(isTermHole, idx, targs, args, content, tpt)
+  def TastyQuoteHole(isTermHole: Boolean, idx: Int, args: List[Tree], tpt: Tree)(implicit src: SourceFile): TastyQuoteHole = new TastyQuoteHole(isTermHole, idx, args, tpt)
 
   // ------ Additional creation methods for untyped only -----------------
 

compiler/src/dotty/tools/dotc/core/tasty/TreePickler.scala

@@ -665,11 +665,12 @@ class TreePickler(pickler: TastyPickler) {
               pickleTree(hi)
               pickleTree(alias)
           }
-        case Hole(_, idx, args, _, tpt) =>
+        case Hole(_, idx, targs, args, _, tpt) =>
           writeByte(HOLE)
           withLength {
             writeNat(idx)
             pickleType(tpt.tpe, richTypes = true)
+            targs.foreach(pickleTree)
             args.foreach(pickleTree)
           }
       }

compiler/src/dotty/tools/dotc/core/tasty/TreeUnpickler.scala

@@ -1439,7 +1439,7 @@ class TreeUnpickler(reader: TastyReader,
               val idx = readNat()
               val tpe = readType()
               val args = until(end)(readTerm())
-              Hole(true, idx, args, EmptyTree, TypeTree(tpe)).withType(tpe)
+              TastyQuoteHole(true, idx, args, TypeTree(tpe)).withType(tpe)
             case _ =>
               readPathTerm()
           }
@@ -1473,7 +1473,7 @@ class TreeUnpickler(reader: TastyReader,
           val idx = readNat()
           val tpe = readType()
           val args = until(end)(readTerm())
-          Hole(false, idx, args, EmptyTree, TypeTree(tpe)).withType(tpe)
+          TastyQuoteHole(false, idx, args, TypeTree(tpe)).withType(tpe)
         case _ =>
           if (isTypeTreeTag(nextByte)) readTerm()
           else {

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

@@ -724,12 +724,13 @@ class RefinedPrinter(_ctx: Context) extends PlainPrinter(_ctx) {
         "Thicket {" ~~ toTextGlobal(trees, "\n") ~~ "}"
       case MacroTree(call) =>
         keywordStr("macro ") ~ toTextGlobal(call)
-      case Hole(isTermHole, idx, args, content, tpt) =>
-        val (prefix, postfix) = if isTermHole then ("{{{", "}}}") else ("[[[", "]]]")
-        val argsText = toTextGlobal(args, ", ")
-        val contentText = toTextGlobal(content)
+      case Hole(isTermHole, idx, targs, args, content, tpt) =>
+        val (prefix, postfix) = if isTermHole then ("${", "}") else ("$[", "]")
+        val targsText = ("[" ~ toTextGlobal(targs, ", ") ~ "]").provided(targs.nonEmpty)
+        val argsText =  ("(" ~ toTextGlobal(args, ", ") ~ ")").provided(args.nonEmpty)
         val tptText = toTextGlobal(tpt)
-        prefix ~~ idx.toString ~~ "|" ~~ tptText ~~ "|" ~~ argsText ~~ "|" ~~ contentText ~~ postfix
+        val contentText = ("|" ~~ toTextGlobal(content)).provided(content ne EmptyTree)
+        prefix ~~ "`" ~ idx.toString ~ "`" ~ targsText ~ argsText ~ ":" ~~ tptText ~~ contentText ~~ postfix
       case CapturingTypeTree(refs, parent) =>
         parent match
           case ImpureByNameTypeTree(bntpt) =>

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

@@ -100,7 +100,7 @@ object PickledQuotes {
   private def spliceTerms(tree: Tree, typeHole: TypeHole, termHole: ExprHole)(using Context): Tree = {
     def evaluateHoles = new TreeMap {
       override def transform(tree: tpd.Tree)(using Context): tpd.Tree = tree match {
-        case Hole(isTermHole, idx, args, _, _) =>
+        case TastyQuoteHole(isTermHole, idx, args, _) =>
           inContext(SpliceScope.contextWithNewSpliceScope(tree.sourcePos)) {
             if isTermHole then
               val quotedExpr = termHole match
@@ -165,15 +165,15 @@ object PickledQuotes {
             val tree = typeHole match
               case TypeHole.V1(evalHole) =>
                 tdef.rhs match
-                  case TypeBoundsTree(_, Hole(_, idx, args, _, _), _) =>
+                  case TypeBoundsTree(_, TastyQuoteHole(_, idx, args, _), _) =>
                     // To keep for backwards compatibility. In some older version holes where created in the bounds.
                     val quotedType = evalHole.nn.apply(idx, reifyTypeHoleArgs(args))
                     PickledQuotes.quotedTypeToTree(quotedType)
                   case TypeBoundsTree(_, tpt, _) =>
                     // To keep for backwards compatibility. In some older version we missed the creation of some holes.
                     tpt
               case TypeHole.V2(types) =>
-                val Hole(_, idx, _, _, _) = tdef.rhs: @unchecked
+                val TastyQuoteHole(_, idx, _, _) = tdef.rhs: @unchecked
                 PickledQuotes.quotedTypeToTree(types.nn.apply(idx))
             (tdef.symbol, tree.tpe)
         }.toMap

compiler/src/dotty/tools/dotc/transform/PickleQuotes.scala

@@ -28,43 +28,42 @@ import scala.annotation.constructorOnly
  *  Transforms top level quote
  *   ```
  *   '{ ...
- *      @TypeSplice type X0 = {{ 0 | .. | contentsTpe0 | .. }}
- *      @TypeSplice type X2 = {{ 1 | .. | contentsTpe1 | .. }}
+ *      @TypeSplice type X0 = $[ `0`: ... | contentsTpe0 ]
+ *      type X1
  *      val x1: U1 = ???
  *      val x2: U2 = ???
  *      ...
- *      {{{ 3 | x1 | contents0 | T0 }}} // hole
+ *      ${ `2`(x1): T0 | contents0 } // Hole
  *      ...
- *      {{{ 4 | x2 | contents1 | T1 }}} // hole
+ *      ${ `3`[X1](x2): T1 | contents1 } // Hole
  *      ...
- *      {{{ 5 | x1, x2 | contents2 | T2 }}} // hole
+ *      ${ `4`(x1, x2): T2 | contents2 } // Hole
  *      ...
  *    }
  *    ```
  *  to
  *    ```
  *     unpickleExprV2(
- *       pickled = [[ // PICKLED TASTY
- *       @TypeSplice type X0 // with bounds that do not contain captured types
- *       @TypeSplice type X1 // with bounds that do not contain captured types
+ *       pickled = tasty""" // PICKLED TASTY
+ *         @TypeSplice type X0 // with bounds that do not contain captured types
+ *         type X1
  *         val x1 = ???
  *         val x2 = ???
  *         ...
- *      {{{ 0 | x1 | | T0 }}} // hole
- *      ...
- *      {{{ 1 | x2 | | T1 }}} // hole
- *      ...
- *      {{{ 2 | x1, x2 | | T2 }}} // hole
+ *         ${ `0`(x1): T0 } // Hole
+ *         ...
+ *         ${ `1`[X1](x2): T1 } // Hole
+ *         ...
+ *         ${ `2`(x1, x2): T2 } // Hole
  *         ...
- *       ]],
+ *       """,
  *       typeHole = (idx: Int, args: List[Any]) => idx match {
  *         case 0 => contentsTpe0.apply(args(0).asInstanceOf[Type[?]]) // beta reduced
- *         case 1 => contentsTpe1.apply(args(0).asInstanceOf[Type[?]]) // beta reduced
  *       },
  *       termHole = (idx: Int, args: List[Any], quotes: Quotes) => idx match {
- *         case 3 => content0.apply(args(0).asInstanceOf[Expr[U1]]).apply(quotes) // beta reduced
- *         case 4 => content1.apply(args(0).asInstanceOf[Expr[U2]]).apply(quotes) // beta reduced
- *         case 5 => content2.apply(args(0).asInstanceOf[Expr[U1]], args(1).asInstanceOf[Expr[U2]]).apply(quotes) // beta reduced
+ *         case 0 => content0.apply(args(0).asInstanceOf[Expr[U1]]).apply(quotes) // beta reduced
+ *         case 1 => content1.apply(args(0).asInstanceOf[Expr[U2]]).apply(quotes) // beta reduced
+ *         case 2 => content2.apply(args(0).asInstanceOf[Expr[U1]], args(1).asInstanceOf[Expr[U2]]).apply(quotes) // beta reduced
  *       },
  *     )
  *    ```
@@ -126,7 +125,7 @@ class PickleQuotes extends MacroTransform {
       private val contents = List.newBuilder[Tree]
       override def transform(tree: tpd.Tree)(using Context): tpd.Tree =
         tree match
-          case tree @ Hole(isTerm, _, _, content, _) =>
+          case tree @ Hole(isTerm, _, _, _, content, _) =>
             if !content.isEmpty then
               contents += content
             val holeType =