Remove TupledFunction

We remove from functions form 3.0 as it is not required for any other language feature. This can be added into 3.1 or later version.

Author: nicolasstucki

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

@@ -894,10 +894,6 @@ class Definitions {
     lazy val RuntimeTuple_isInstanceOfEmptyTuple: Symbol = RuntimeTupleModule.requiredMethod("isInstanceOfEmptyTuple")
     lazy val RuntimeTuple_isInstanceOfNonEmptyTuple: Symbol = RuntimeTupleModule.requiredMethod("isInstanceOfNonEmptyTuple")
 
-  @tu lazy val TupledFunctionTypeRef: TypeRef = requiredClassRef("scala.util.TupledFunction")
-  def TupledFunctionClass(using Context): ClassSymbol = TupledFunctionTypeRef.symbol.asClass
-  def RuntimeTupleFunctionsModule(using Context): Symbol = requiredModule("scala.runtime.TupledFunctions")
-
   // Annotation base classes
   @tu lazy val AnnotationClass: ClassSymbol = requiredClass("scala.annotation.Annotation")
   @tu lazy val ClassfileAnnotationClass: ClassSymbol = requiredClass("scala.annotation.ClassfileAnnotation")

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

@@ -77,50 +77,6 @@ class Synthesizer(typer: Typer)(using @constructorOnly c: Context):
     }
   end synthesizedTypeTest
 
-  val synthesizedTupleFunction: SpecialHandler = (formal, span) =>
-    formal match
-      case AppliedType(_, funArgs @ fun :: tupled :: Nil) =>
-        def functionTypeEqual(baseFun: Type, actualArgs: List[Type],
-            actualRet: Type, expected: Type) =
-          expected =:= defn.FunctionOf(actualArgs, actualRet,
-            defn.isContextFunctionType(baseFun), defn.isErasedFunctionType(baseFun))
-        val arity: Int =
-          if defn.isErasedFunctionType(fun) || defn.isErasedFunctionType(fun) then -1 // TODO support?
-          else if defn.isFunctionType(fun) then
-            // TupledFunction[(...) => R, ?]
-            fun.dropDependentRefinement.dealias.argInfos match
-              case funArgs :+ funRet
-              if functionTypeEqual(fun, defn.tupleType(funArgs) :: Nil, funRet, tupled) =>
-                // TupledFunction[(...funArgs...) => funRet, ?]
-                funArgs.size
-              case _ => -1
-          else if defn.isFunctionType(tupled) then
-            // TupledFunction[?, (...) => R]
-            tupled.dropDependentRefinement.dealias.argInfos match
-              case tupledArgs :: funRet :: Nil =>
-                defn.tupleTypes(tupledArgs.dealias) match
-                  case Some(funArgs) if functionTypeEqual(tupled, funArgs, funRet, fun) =>
-                    // TupledFunction[?, ((...funArgs...)) => funRet]
-                    funArgs.size
-                  case _ => -1
-              case _ => -1
-          else
-            // TupledFunction[?, ?]
-            -1
-        if arity == -1 then
-          EmptyTree
-        else if arity <= Definitions.MaxImplementedFunctionArity then
-          ref(defn.RuntimeTupleFunctionsModule)
-            .select(s"tupledFunction$arity".toTermName)
-            .appliedToTypes(funArgs)
-        else
-          ref(defn.RuntimeTupleFunctionsModule)
-            .select("tupledFunctionXXL".toTermName)
-            .appliedToTypes(funArgs)
-      case _ =>
-        EmptyTree
-  end synthesizedTupleFunction
-
   /** If `formal` is of the form Eql[T, U], try to synthesize an
     *  `Eql.eqlAny[T, U]` as solution.
     */
@@ -408,7 +364,6 @@ class Synthesizer(typer: Typer)(using @constructorOnly c: Context):
     defn.ClassTagClass        -> synthesizedClassTag,
     defn.TypeTestClass        -> synthesizedTypeTest,
     defn.EqlClass             -> synthesizedEql,
-    defn.TupledFunctionClass  -> synthesizedTupleFunction,
     defn.ValueOfClass         -> synthesizedValueOf,
     defn.Mirror_ProductClass  -> synthesizedProductMirror,
     defn.Mirror_SumClass      -> synthesizedSumMirror,

docs/docs/reference/other-new-features/tupled-function.md

@@ -101,8 +101,6 @@ sidebar:
               url: docs/reference/other-new-features/parameter-untupling.html
             - title: Kind Polymorphism
               url: docs/reference/other-new-features/kind-polymorphism.html
-            - title: Tupled Function
-              url: docs/reference/other-new-features/tupled-function.html
             - title: threadUnsafe Annotation
               url: docs/reference/other-new-features/threadUnsafe-annotation.html
             - title: targetName Annotation