Hide context bounds expansion for poly functions under modularity feature

Author: KacperFKorban

compiler/src/dotty/tools/dotc/parsing/Parsers.scala

@@ -68,7 +68,7 @@ object Parsers {
     def acceptsVariance =
       this == Class || this == CaseClass || this == Hk
     def acceptsCtxBounds =
-      !(this == Hk)
+      !(this == Type || this == Hk)
     def acceptsWildcard =
       this == Type || this == Hk
 
@@ -3452,7 +3452,9 @@ object Parsers {
             else ident().toTypeName
           val hkparams = typeParamClauseOpt(ParamOwner.Hk)
           val bounds =
-            if paramOwner.acceptsCtxBounds then typeAndCtxBounds(name) else typeBounds()
+            if paramOwner.acceptsCtxBounds then typeAndCtxBounds(name)
+            else if in.featureEnabled(Feature.modularity) && paramOwner == ParamOwner.Type then typeAndCtxBounds(name)
+            else typeBounds()
           TypeDef(name, lambdaAbstract(hkparams, bounds)).withMods(mods)
         }
       }

compiler/src/dotty/tools/dotc/typer/Typer.scala

@@ -1930,7 +1930,8 @@ class Typer(@constructorOnly nestingLevel: Int = 0) extends Namer
 
   def typedPolyFunction(tree: untpd.PolyFunction, pt: Type)(using Context): Tree =
     val tree1 = desugar.normalizePolyFunction(tree)
-    val tree2 = desugar.expandPolyFunctionContextBounds(tree1)
+    val tree2 = if Feature.enabled(Feature.modularity) then desugar.expandPolyFunctionContextBounds(tree1)
+                else tree1
     if (ctx.mode is Mode.Type) typed(desugar.makePolyFunctionType(tree2), pt)
     else typedPolyFunctionValue(tree2, pt)
 

tests/pos/contextbounds-for-poly-functions.scala

@@ -1,7 +1,6 @@
 import scala.language.experimental.modularity
 import scala.language.future
 
-
 trait Ord[X]:
   def compare(x: X, y: X): Int