Add QuotedRuntimePatterns_higherOrderHoleWithTypes

This commit also allows splitQuotePattern to support type args

Author: zeptometer

compiler/src/dotty/tools/dotc/core/Definitions.scala

@@ -882,6 +882,7 @@ class Definitions {
   @tu lazy val QuotedRuntimePatterns: Symbol = requiredModule("scala.quoted.runtime.Patterns")
     @tu lazy val QuotedRuntimePatterns_patternHole: Symbol = QuotedRuntimePatterns.requiredMethod("patternHole")
     @tu lazy val QuotedRuntimePatterns_higherOrderHole: Symbol = QuotedRuntimePatterns.requiredMethod("higherOrderHole")
+    @tu lazy val QuotedRuntimePatterns_higherOrderHoleWithTypes: Symbol = QuotedRuntimePatterns.requiredMethod("higherOrderHoleWithTypes")
     @tu lazy val QuotedRuntimePatterns_patternTypeAnnot: ClassSymbol = QuotedRuntimePatterns.requiredClass("patternType")
     @tu lazy val QuotedRuntimePatterns_fromAboveAnnot: ClassSymbol = QuotedRuntimePatterns.requiredClass("fromAbove")
 

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

@@ -205,8 +205,16 @@ object QuotePatterns:
           val patType1 = patType.translateFromRepeated(toArray = false)
           val pat1 = if (patType eq patType1) pat else pat.withType(patType1)
           patBuf += pat1
-          if args.isEmpty then ref(defn.QuotedRuntimePatterns_patternHole.termRef).appliedToType(tree.tpe).withSpan(tree.span)
-          else ref(defn.QuotedRuntimePatterns_higherOrderHole.termRef).appliedToType(tree.tpe).appliedTo(SeqLiteral(args, TypeTree(defn.AnyType))).withSpan(tree.span)
+          if typeargs.isEmpty && args.isEmpty then ref(defn.QuotedRuntimePatterns_patternHole.termRef).appliedToType(tree.tpe).withSpan(tree.span)
+          else if typeargs.isEmpty then
+            ref(defn.QuotedRuntimePatterns_higherOrderHole.termRef)
+              .appliedToType(tree.tpe)
+              .appliedTo(SeqLiteral(args, TypeTree(defn.AnyType)))
+              .withSpan(tree.span)
+          else ref(defn.QuotedRuntimePatterns_higherOrderHoleWithTypes.termRef)
+            .appliedToTypeTrees(List(TypeTree(tree.tpe), tpd.hkNestedPairsTypeTree(typeargs)))
+            .appliedTo(SeqLiteral(args, TypeTree(defn.AnyType)))
+            .withSpan(tree.span)
         case _ =>
           super.transform(tree)
       }

library/src/scala/quoted/runtime/Patterns.scala

@@ -1,6 +1,7 @@
 package scala.quoted.runtime
 
 import scala.annotation.{Annotation, compileTimeOnly}
+import scala.annotation.experimental
 
 @compileTimeOnly("Illegal reference to `scala.quoted.runtime.Patterns`")
 object Patterns {
@@ -26,6 +27,14 @@ object Patterns {
   @compileTimeOnly("Illegal reference to `scala.quoted.runtime.Patterns.higherOrderHole`")
   def higherOrderHole[U](args: Any*): U = ???
 
+  /** A higher order splice in a quoted pattern is desugared by the compiler into a call to this method.
+   *
+   *  Calling this method in source has undefined behavior at compile-time
+   */
+  @experimental
+  @compileTimeOnly("Illegal reference to `scala.quoted.runtime.Patterns.higherOrderHole`")
+  def higherOrderHoleWithTypes[U, T](args: Any*): U = ???
+
   /** A splice of a name in a quoted pattern is that marks the definition of a type splice.
    *
    *  Adding this annotation in source has undefined behavior at compile-time